Isotope Geology of the Norilsk Deposits [1st ed.] 978-3-030-05215-7;978-3-030-05216-4

Table of contents :
Front Matter ....Pages i-ix
Helium and Argon Isotopes (Vladimir Khalenev, Edward Prasolov, Konstantin Gruzdov, Dmitry Zavilejsky, Kirill Lokhov, Edward Prilepsky et al.)....Pages 1-47
Sulphur Isotopes (Edward Prasolov, Vladimir Khalenev, Boris Belyatsky, Edward Prilepsky, Tatiana Nazarova)....Pages 49-72
Copper and Nickel Isotopes (Sergey Sergeev, Igor Kapitonov, Robert Krymsky, Dmitriy Sergeev, Elena Adamskaya, Nikolay Goltsin)....Pages 73-88
Strontium and Neodymium Isotopes (Yevgeny Bogomolov, Boris Belyatsky, Robert Krymsky, Yury Pushkarev)....Pages 89-132
Lead Isotopes (Boris Belyatsky, Yury Pushkarev, Edward Prasolov, Igor Kapitonov, Robert Krymsky, Sergey Sergeev)....Pages 133-187
Lutetium and Hafnium Isotopes in Zircons (Igor Kapitonov, Kirill Lokhov, Dmitriy Sergeev, Elena Adamskaya, Nikolay Goltsin, Sergey Sergeev)....Pages 189-205
Isotope Correlations in Rocks and Ores of Major Intrusions in the Norilsk District (Oleg Petrov, Edward Prasolov, Sergey Sergeev, Yury Pushkarev)....Pages 207-213
Isotope Chronology of Geological Processes (O. Petrov, S. Sergeev, R. Krymsky, S. Presnyakov, N. Rodionov, A. Larionov et al.)....Pages 215-302
Back Matter ....Pages 303-306

Citation preview

Springer Geology

Oleg Petrov Editor

Isotope Geology of the Norilsk Deposits

Springer Geology Series Editors Yuri Litvin, Institute of Experimental Mineralogy, Moscow, Russia Abigail Jiménez-Franco, Del. Magdalena Contreras, Mexico City, Estado de México, Mexico

The book series Springer Geology comprises a broad portfolio of scientific books, aiming at researchers, students, and everyone interested in geology. The series includes peer-reviewed monographs, edited volumes, textbooks, and conference proceedings. It covers the entire research area of geology including, but not limited to, economic geology, mineral resources, historical geology, quantitative geology, structural geology, geomorphology, paleontology, and sedimentology.

More information about this series at http://www.springer.com/series/10172

Oleg Petrov Editor

Isotope Geology of the Norilsk Deposits

123

Editor Oleg Petrov A. P. Karpinsky Russian Geological Research Institute (VSEGEI) St. Petersburg, Russia

ISSN 2197-9545 ISSN 2197-9553 (electronic) Springer Geology ISBN 978-3-030-05215-7 ISBN 978-3-030-05216-4 (eBook) https://doi.org/10.1007/978-3-030-05216-4 Library of Congress Control Number: 2019935843 Translation from the Russian language edition: Изотопная геология норильских месторождений, © Коллектив авторов 2017, © ФГБУ «Всероссийский научно-исследовательский геологический институт им. А. П. Карпинского» 2017. Published by Издательство ВСЕГЕИ. All Rights Reserved. © Springer Nature Switzerland AG 2019 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG. The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Contents

Helium and Argon Isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vladimir Khalenev, Edward Prasolov, Konstantin Gruzdov, Dmitry Zavilejsky, Kirill Lokhov, Edward Prilepsky and Vera Badinova

1

Sulphur Isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Edward Prasolov, Vladimir Khalenev, Boris Belyatsky, Edward Prilepsky and Tatiana Nazarova

49

Copper and Nickel Isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sergey Sergeev, Igor Kapitonov, Robert Krymsky, Dmitriy Sergeev, Elena Adamskaya and Nikolay Goltsin

73

Strontium and Neodymium Isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . Yevgeny Bogomolov, Boris Belyatsky, Robert Krymsky and Yury Pushkarev

89

Lead Isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Boris Belyatsky, Yury Pushkarev, Edward Prasolov, Igor Kapitonov, Robert Krymsky and Sergey Sergeev Lutetium and Hafnium Isotopes in Zircons . . . . . . . . . . . . . . . . . . . . . . 189 Igor Kapitonov, Kirill Lokhov, Dmitriy Sergeev, Elena Adamskaya, Nikolay Goltsin and Sergey Sergeev Isotope Correlations in Rocks and Ores of Major Intrusions in the Norilsk District . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Oleg Petrov, Edward Prasolov, Sergey Sergeev and Yury Pushkarev Isotope Chronology of Geological Processes . . . . . . . . . . . . . . . . . . . . . . 215 O. Petrov, S. Sergeev, R. Krymsky, S. Presnyakov, N. Rodionov, A. Larionov, E. Lepekhina and D. Sergeev Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303

v

Introduction

The methodology of isotope and geochemical studies involves the most complicated analytical procedures to obtain high-quality results and application to the analytical data of the genetic criteria developed by isotope geochemistry. Our results and recommendations can be regarded as innovative; they are for the first time based on such a broad and complete (11 systems) set of studies of independent isotope systems with nano- and micro-amounts of matter. None of the known isotope geochemical and geochronological methods is universal and self-sufficient in solving various geological problems. A successful application of such methods is achieved through an integrated approach. It is possible to ensure, technically and organizationally, the necessary efficiency of the studies using a wide range of methods including the finest ones only within a single internationally certified analytical centre. In this regard, the importance of using the facilities of the Centre of Isotopic Research (CIR) at VSEGEI for the creation, setting-up, adaptation, development, approval, certification and practical application of the innovative methods of isotopic studies of geological objects cannot be overestimated. In samples of ores, rocks and minerals, isotopic composition of the components were studied including those in the fluids of the mineral formation environment in general and ore formation environment, in particular. On the basis of the analytical results, the genetic isotope criteria were formulated making it possible to diagnose the sources of the matter of rocks and ores, to reveal the formation conditions of mineral deposits. Especially important is the diagnosis of the contribution of matter of different geospheres—crust and mantle. Many researchers now regard the crust–mantle interaction as a determining factor in the ore generation processes. An effective use of the obtained empirical isotope data allows not only to create new, more correct models of deposit formation, but also to find the isotopic search criteria. Isotopic composition of helium (3He/4He isotope ratio) is used to diagnose the contribution of the mantle helium. The above ratio in the upper mantle is about 600-fold versus that in helium forming in crustal rocks. This is the strongest and most unambiguous criterion of the mantle origin of fluids. vii

viii

Introduction 40

Ar/36Ar isotope ratio makes it possible to unambiguously and with a high degree of precision detect the atmospheric component of argon and other gases as well as the association of mineral-forming fluids with near-surface sedimentation and infiltration water. The study of noble gas isotopes offers extensive possibilities for determining the formation conditions of the sources of mineral matter. We studied the isotopic composition of noble gases (helium and argon) in gas– liquid microinclusions (but not in the crystal lattice of minerals) to avoid distortions caused by radioactive processes in the “hard” part of the rocks. Isotopic composition of helium giving a possibility of a numerical determination of the contribution of the crustal and mantle components in fluids as well as the composition of argon was studied in rock samples from a number of intrusions in the Norilsk district. Isotope helium–argon systematics is most reliable for determining the source of the fluid and a quantitative assessment of the contribution of different sources to the formation of ore-transporting fluids. It allows a quantitative evaluation of the main reservoirs of volatiles—the upper mantle, the continental crust, surface water. The systematics allows a reliable control of the evolution of fluid systems. Isotopic composition of sulphur (d34S value) which is in the ore minerals— sulphides, in some cases—allows diagnosing their genesis. In particular, it is possible to assess the presence of mantle sulphur as well as sulphur of evaporites. Results of rubidium–strontium (Rb–Sr) and samarium–neodymium (Sm–Nd) analysis point to the source of the matter of rock-forming and metasomatic minerals. To establish the possible sources of ore matter, isotopic composition of lead in sulphides is determined using local sampling (LA–ICP) as well as sulphur in the same samples. A lot of data were obtained on the age of rocks and occurrence time of geological processes on the basis of rhenium–osmium (Re–Os) and in situ uranium– lead dating of accessory zircons and ore minerals from a broad range of rocks. Multisystem isotopic studies of a series of intrusions were carried out at CIR VSEGEI in two stages. In 2003–2008 (I stage) and 2012–2014 (II stage), they were aimed at determining the sources of matter, time and generation pattern of ore bodies which are of great importance. A large collection of new samples (more than 250) taken from the exploratory wells in 22 intrusions in the Norilsk district was studied. New quantitative genetic indicators of 11 different isotopic systems were obtained which, in general, allow refining the generation models of unique Cu–Ni–PGE-deposits. For example, the origin of silicate matter of the Norilsk intrusions was traditionally regarded as mantle. However, the first study of isotopic composition of fluid components of He and Ar carried out by S. S. Neruchev and E. M. Prasolov and of sulphur performed by L. N. Grinenko revealed an extensive crust–mantle interaction. Under governmental contracts with the Federal Agency on Mineral Resources and contracts with the Norilsk Nickel, VSEGEI Centre of Isotopic Research made over 5000 isotopic analyses including measurements of helium and argon of fluid microinclusions in rocks and ores, as well as sulphur, copper and nickel from

Introduction

ix

sulphides. The absolute (isotopic) age of sulphide ores and zircons from rocks in intrusions characterized by different ore potential was determined. Eleven isotopic systems were studied in different substances—in silicate matter, in ore (in sulphide), in paleofluids. Data of Russian and foreign researchers of the Norilsk region were also used to obtain an integrated picture. Team of authors is grateful to the PJSC MMS Norilsk Nickel for financial support of the publication and fruitful cooperation in studying geology and metallogeny of the Norilsk ore district.

Helium and Argon Isotopes Vladimir Khalenev, Edward Prasolov, Konstantin Gruzdov, Dmitry Zavilejsky, Kirill Lokhov, Edward Prilepsky and Vera Badinova

Abstract The results of helium and argon isotope composition measurements (3He/4He, 40Ar/36Ar ratios and others) are presented in the chapter. In paleofluids from the Norilsk intrusions, the crustal helium is dominant, and the fraction of mantle helium is in the range from 0.1 to 22%. The contribution of crustal helium (0.1–4%) in rich and medium intrusions is especially low. In this parameter, poor intrusions (4–22%) are significantly different, with much more mantle helium. In fluid inclusions of the studied targets, the share of air argon is high, 60–100%. It is especially high in rich intrusions, from 88 to 100%. Consequently, air-saturated waters from enclosing sedimentary rocks actively participated in the formation of rocks and ores of the intrusions in the region. Average (by reserves) intrusions differ significantly from the rich ones; they contain only 60–85% of atmospheric argon.

Geochemistry of isotopes of noble gases offers to the researchers unique possibilities of determining the origin of fluids. Helium isotopic composition (3He/4He isotope ratio) is considered to be, virtually, the only reliable and strong criterion of the association of mineral-forming fluids with mantle. It was found that helium isotope ratio in the Earth’s upper mantle (1.2
10−5) is approximately 600 times higher than in helium forming in crustal rocks (about 2
10−8) [1–3]. This makes it possible to reveal and calculate the share of mantle helium, if it exceeds 1% of total helium in the sample. Isotopic composition of argon (40Ar/36Ar ratio) enables to precisely calculate the share of argon of atmospheric origin in mineral-forming fluids. The only path for air argon penetration into the subsurface is migration with infiltration and sedimentation water. Therefore, isotope ratio indicates the extent of participation of near-surface water in mineral formation, or the degree of openness of geosystems for near-surface fluids.

V. Khalenev (&)  E. Prasolov  K. Gruzdov  D. Zavilejsky  K. Lokhov  E. Prilepsky  V. Badinova Russian Geological Research Institute (VSEGEI), St. Petersburg, Russia e-mail: [email protected] © Springer Nature Switzerland AG 2019 O. Petrov (ed.), Isotope Geology of the Norilsk Deposits, Springer Geology, https://doi.org/10.1007/978-3-030-05216-4_1

1

2

V. Khalenev et al.

1 Methodology, Samples According to some methodological considerations, gas-liquid microinclusions were used as a direct study object. Extraction of gases from inclusions was performed by mechanical destruction of samples (weighing 2 g) in vacuum applying the methodologies developed in [4, 5]. The released noble gases were cleaned from active components using getters in an inflow system. Light gases (He + Ne) were separated from heavy gases (Ar + Kr + Xe) using activated carbon at −196 °C. Light and heavy gases were successively transferred to the analyzer cell of mass spectrometer Micromass NG5400 (England, Manchester), where under the static pumping mode 3He/4He, 4 He/20Ne, 40Ar/36Ar, 38Ar/36Ar ratios were determined as well as the number of 4He and 40Ar isotopes. Helium and argon blank of the entire equipment set: 4He of the inlet systems 4
10−9 cm3, full 2.2
10−8 cm3 or 1.1
10−8 cm3/g; Ar40 of the inlet system 6
10−9 cm3, full 1.0
10−8 cm3 or 5
10−9 cm3/g; isotope ratio close to that of air. Random errors (1r) based on the results of repeated isotope measurements in samples at 2–5 V signal constituted 3He/4He ratio of 4% with at value *6
10−8 and (1.2)% at (2–8)
10−7. Measurement errors of 4He/20Ne ratio are *10%; those of 40Ar/36Ar, 0.05–0.18%; and 38Ar/36Ar, 0.05–0.15%. Measurement accuracy appeared to be quite sufficient for a correct data interpretation. Analytical data on helium and argon isotopes obtained at the I stage [6] using MI9303 and MS10 mass spectrometers had approximately the same metrological characteristics. They were slightly better when studying gases from the crystal lattice; gases were extracted by melting samples at 1700 °C in a high-vacuum jacketed resistance furnace. Presumably, the attained metrological characteristics are sufficient for obtaining correct results on the spread of noble gas isotopes in rocks of the Norilsk-Taimyr district intrusions. For the convenience of geological interpretation of data, isotope ratios were transformed to the values showing the share of mantle helium (m), atmospheric (a) and radiogenic (r) argon. Calculation of the first of these values was carried out proceeding from the values of 3He/4He ratio in the Earth’s mantle and crust 1.2
10−5 and 2
10−8 from the following formula: 3

mð%Þ ¼ Hemantle =He =







 3 He/4 He crust sample
3 He/ 4 He mantle

He/4 He


100:

Share of atmospheric helium in the vast majority of samples was very small (the first thousandths), and the corrections made [2] practically did not change the measured value of 3He/4He ratio in samples.

Helium and Argon Isotopes

3

Calculation of the shares of air and radiogenic argon was performed taking into account the atmospheric ratio of 40Ar/36Ara 296: 

Ar=36 Ar  að%Þ ¼ Ara =Ar =  40 Ar=36 Ar 40

 a


100:

sample

rð%Þ ¼ Arr =Ar ¼ 100a: The first studies of helium and argon isotopes in 32 samples from the Talnakh and some other intrusions in the Norilsk district [6] showed that the inclusions from mafic rocks and ores were dominated by crustal helium and atmospheric argon. At the II stage (2004–2005), the distribution of isotopes of noble gases in gas-liquid inclusions from rocks and crystal lattice of minerals in Norilsk-1 intrusion was investigated (8 samples). Later, at the III stage (2006–2008), at CIR VSEGEI, over 70 samples of noble gas isotopes were studied in 16 intrusions of the Norilsk-Taimyr district with varying degrees of ore content (inclusions were dominated by crustal helium and air argon). It also appeared that the isotopic composition of noble gases was different in intrusions depending on their ore content. This made it possible to propose a He–Ar isotopic criterion of ore presence in intrusions. At the last, IV stage (2012–2014), isotopic composition of helium and argon was studied to improve the reliability of Table 1 Intrusives studied at the I, II and III stages (1995, 2005, 2008) Intrusive

Borehole

Types of intrusives

Kharaelakh

KZ-963

Commercial ore-bearing (rich)

Talnakh

OUG-2, KZ-1710, KZ-1739

Norilsk-1

MN-2 (MS-33)

Chernogorsk

MP-2bis

Vologochan

OV-29

South Pyasina

OV-25

Zub-Marksheidersky

MP-27

Zelenaya Griva

F-233

Tulaj-Kiryak

2.18

Bootankaga

8A

Lower Fokino

NF

Maslovsky

OM-31

Lower Talnakh

TG-31

Lower Norilsk

NP-37

Mikchangda

MD-48

Binyuda

S-1

Non-commercial ore-bearing (average)

Weakly ore-bearing (poor)

Satellites of commercial ore-bearing intrusives

Potentially ore-bearing

4

V. Khalenev et al.

Table 2 Objects studied at the IV stage (2014) Object

Borehole

Kharaelakh intrusive, Oktyabrskoe deposit Western flank ZF-13, ZF-30, KZ-931, KZ-952, KZ1319 Central part PT-2, KZ-1089, KZ-1112, KZ-1535 Southern flank KZ-361, KZ-1084 Total 11 boreholes Deposits Talnakh KZ-774 Zub-Marksheidersky MP-25, 13074 Chernogorsk MP-2 Maslovsky OM-32, OM-123, OM-10 Areas Vologochan OV-28, OV-36 Koevo PK-11 Tangnarylakh 13090, 13096, 13097 Mokulaj 13005, 13016, 13020, 13033, 13049 Oganer Listvyanka Krasny Kamen

Number of samples 20, including 6 (ore) 17, including 9 (ore) 5, including 5 (ore) 42, including 20 (ore) 1 2 1 12, rocks 10, rocks 7, basalts 8, gabbro 5, basalts 2 2 2

the proposed criteria. In particular, isotopic measurements were performed on individual intrusions in a group of wells, but not in a single well. Isotopic heterogeneity of intrusions was estimated, and the amount of the material was obtained (wells, samples) required for a correct evaluation of ore presence. In addition, isotopic studies of ores proper were significantly expanded—of massive (rich) and disseminated ones. The list of the studied objects is presented in Tables 1 and 2. At all the four stages, noble gases from gas-liquid inclusions were investigated. This was due to the fact that the contents of microinclusions disseminated in minerals and inter-mineral space of rocks is the only reliable evidence of the origin of mineral-forming fluids. The study of the gaseous phase of inclusions is particularly important when investiga-ting noble gases due to the hazard of radiogenic isotope formation in the crystal lattice of minerals. In this work, we investigate the occurrence of noble gas isotopes in gas-liquid inclusions. Isotopic composition of helium and argon was studied in relic fluids preserved in gas-liquid microinclusions in minerals and rock pores. Rock and ore samples were taken from different drill core depth intervals. Each intrusion was characterized, on the average, by 5–6 bulk samples. At the I, II and III stages, the information about helium and argon isotopes in more than 100 rock and mineral samples was obtained.

Helium and Argon Isotopes

5

Fig. 1 Area of work

The investigated intrusions represented three main geological economic types: commercially mineralized containing solid (massive), disseminated and vein-disseminated ores (rich); mineralized (non-commercial) containing disseminated and vein-disseminated ores (average); weakly mineralized, not containing commercial mineralization (poor). Satellites of commercially mineralized intrusions are distinguished as an independent type. Also investigated were poorly studied intrusions—objects of a prognostic assessment. Names of intrusions, well numbers and belonging to the above types are presented in Tables 1 and 2, and their distribution within the Norilsk-Taimyr district is shown in Figs. 1 and 2. One part of the samples was provided by the researchers of IGEM RAS and KNIIGiMS, another one was collected in the field by the geologists of VSEGEI and VNIIOkeangeologia. Published data on the Talnakh, Norilsk-1 and certain Taimyr intrusions were used [6–12]. The use of bulk rock samples significantly simplified the procedure of sample preparation for the analysis. No significant differences were revealed in isotopic composition of bulk samples and monomineral fractions (olivine, pyroxene). The identified isotopic variations along the section of the intrusions appeared to be relatively low, and the averaged isotopic characteristics were acceptable for determining the difference (or similarity) between the intrusions.

6

V. Khalenev et al.

Fig. 2 Location of the studied intrusions in the Norilsk district. 1—effusive traps; 2—sedimentary deposits; 3—trappean intrusions; 4—granitoid intrusions; 5—regional faults. Numbers of intrusives (in circles): 1—Kharaelakh; 2—Talnakh; 3—Norilsk-1; 4—Chernogorsk; 5—Vologochan; 6—South Pyasina; 7—Zub-Marksheidersky; 8—Zelenaya Griva; 9—Lower Fokino; 10—Lower Talnakh; 11— Lower Norilsk; 12—Mikchangda

A comparison of measurement results showed the lack of significant differences between the rocks and ores. This is important not only for approval of the notions about the unity of the processes of formation/alteration of rocks and ores. It is, undoubtedly, convenient for the practical diagnosis of ore presence prospects, since it allows using as test samples not only ores (not yet discovered!), but also rocks from the section of the intrusion.

He,
10−6 cm3/ g He/20Ne (meas.)

4

He/4He (corr.)
10−6

3

0.51 5.7 0.46 0.56 0.91 0.11 0.35 4.7 0.27 0.38 5.1 0.31 0.50 4.7 0.43 0.51 2.8 0.40 0.78 0.088 2500 Note Zr—zircon, Bd—baddeleyite, Bt—biotite, Hb—hornblende, Pl—plagioclase, Ol—olivine, WR—whole rock, PR1 and 2—Proterozoic, Early and Late, AR—Archaean, IDTIMS—isotopic dilution method, thermionization mass spectrometry, SIMS SHRIMP—secondary ion mass spectrometry, ion microprobe

Norilsk district is characterized by the presence above basalt covers of a complex rock assemblage, Paleozoic sediments to 5 km thick and more ancient (900– 2300 Ma [22]) Late Proterozoic volcanogenic sedimentary series to 4 km thick and Proterozoic granite-gneiss basements. This suggests the presence in mafic

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O. Petrov et al.

intrusions of a large number of xenogenic refractory zircon trapped during penetration and partial assimilation of fusible felsic host rocks and present both in the form of individual grains and as seed cores during the growth of proper magmatic zircon. A good benchmark for dating is the age of zircons and baddeleyite in leucogabbro from Norilsk-1 intrusion obtained in 1996 by the classical method of isotope dilution ID-TIMS [11]. This determination corresponds to 251.2 ± 0.3 Ma and enables culling out multiple “ancientized” datings, associated with a wide presence of inherited zircon phases, obtained by local SIMS. It is obvious that most of U–Pb ratio variations reflect the heterogeneity in factors such as the nonradiogenic lead content, degree of secondary alteration, admixture of inherited component, fluctuation in measuring parameters. This follows from the identity of such variations in dating of zircons, leucogabbros and other rocks in all intrusions from the Norilsk district. In fact, only two age valuegroups are real, 255–240 and 230–220 Ma. They can be traced in different intrusions and identify two principalstages in the evolution of magmatic and ore systems of Norilsk type intrusions, magmatic and postmagmatic. Modern geochronology of the Norilsk district intrusions is mainly based on the U–Pb SIMS SHRIMP method by accessory zircons. The very presence of igneous zircons in mafic intrusive rocks is an uncharacteristic phenomenon. Nevertheless, in gabbro dolerites from Norilsk-1, Talnakh, and Kharaelakh intrusions, zircon content amounts to 50–70 ppm, corresponding to >100 ppm of zircon in the rock. The major advantage of local SIMS SHRIMP is a preliminary identification of the analysed volume (*30  20  2 µm) within the zircon grain that enables to choose for dating an undisturbed area with a known genetic identity. The most complete analytical information that affords to reconstruct all thestages of non-ferrous and precious metal deposits formation with accessory zircon has been obtained by us for the main mineralized intrusions in the Norilsk district. Consideration of the analytical results in their entirety, taking into account geochemical characteristics of the studied zircons, their internal structure and location of the source geological samples suggests the following data interpretation for the studied intrusions. The main difficulty at thisstage was to separate the real age of zircon crystallization from the measured values. All intrusions contain “magmatic” zircons (250–240 Ma) presented by large (to 200 µm) subidiomorphic crystals with a distinct oscillatory zoning, containing a small number of gas-liquid and mineral inclusions and unusual geochemical characteristics—Th/U ratio in them is from 1.5 to 4.5 at very high uranium concentrations, generally from 1000 to 6000 ppm (Fig. 1a). Most high-uranium zircons are in the Talnakh intrusion. Age of magmatic zircon crystallization corresponds to the age of silicate matrix of intrusion rocks. This indicates a high probability of the presence of uranium mineralization in the genetic and spatial association with mafic intrusions. Along with magmatic crystals, zircon population from intrusions rocks contains inherited grains (trapped from various assimilated host rocks during injection). Inherited (allochthonous) zircons with ages between 0.3 and 2.7 Ga may be present

Isotope Chronology of Geological Processes

223

Fig. 1 Characteristic varieties of zircons from intrusives of Norilsk Region. a magmatic; b inherited; c secondary. Diameter of circumferences (sampling points) 30 µm

in the form of cores in magmatic crystals (Fig. 1b); recrystallized and corroded secondary zircons (220–230 Ma) arising from metasomatic recrystallization of rocks can form fouling shells (Fig. 1c). The number and variety of inherited and post-magmatic zircons are directly dependent on the intensity of secondary alteration and extent of rock strata assimilation. Thus, dating of all the discovered zircon varieties enables to characterize the time of crystallization and recrystallization of intrusive rocks and to assess the contaminant source. It is noteworthy that varieties of inherited zircons are different for the three main intrusions in the Norilsk district (Table 3). These differences can be explained by the fact that the Norilsk district is spatially confined to the development area of near N-S Riphean (Late Proterozoic) trough, which accumulated thick sedimentary beds with volcanic formations. Igneous rocks from the Cambrian to the Upper Paleozoic have not been revealed. As mentioned above, Paleozoic sediments, Late Proterozoic volcanicsedimentary strata and granite-gneiss basement are present below the basalt covers. This explains the presence in mafic intrusions of a large number of xenogenic refractory zircon trapped during penetration and partial assimilation of fusible felsic host rocks. Such zircon is present both in the form of individual grains and as seed cores during the growth of proper magmatic zircon occurring at magmatic silicate melt crystallization. A convincing illustration of the data above is a large bulk of our evidence for Norilsk-1 intrusion (Fig. 2), which allows to see a statistically reasonable distinction between younger, proper magmatic zircons, and older, metasomatic ones, the

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O. Petrov et al.

Table 3 U–Pb age of zircons of different genesis and Re–Os isochron age of sulphide ores in mafic intrusives of the Norilsk District (Ma) Intrusive

Magmatic zircons

Postmagmatic zircons

251 ± 2 252 ± 8

228 ± 2 230–235

Inherited zircons

Massive and disseminated ores

1900 – 290, 250 ± 2 347 ± 16 Talnakh 256 ± 1 221–231 None 251 ± 13 Zub-Marksheidersky 249 ± 4 225 None 248 ± 14 Imangda 243 ± 4 223 ± 3 320–330 – Chernogorsk 244 ± 3 227 290 248 ± 14 Pyasina-Vologochan 242 ± 10 225 330, 2730 248 ± 14 Mikchangda 256 ± 2 230 293 – South Pyasina 242 ± 3 210 None 248 ± 14 Kruglogorsky 241 ± 4 225 303–306 – Zelenaya Griva 241 ± 6 None None 250 ± 14 Lower Talnakh 254 ± 4 220–230 270, 300 247 ± 45 Lower Norilsk 247 ± 6 230 1900 251 ± 20 Binyuda (Taimyr) 249 ± 11 None None 251 ± 13 Note For calculations, only concordant and subconcordant (>85% concordance) values of UPb age were used. Initial UPb isotope data for zircons are given in Table 6 Norilsk-1 Kharaelakh

formation of which occurred simultaneously with the injection in the Norilsk district of later granodiorite (e.g., Bolgotokh). Older datings are mostly confined to the marginal parts of grains. The total age data aggregate also allows us to identify statistically (and, probably, geologically) a significant difference in the age of magmatic crystallization of the Norilsk district intrusions. There are “early” (255–250 Ma) and “late” (245– 240 Ma) intrusions at virtually indistinguishable geochemical composition of rocks building them up and a close spatial conjugation of intrusions. The time difference between these two magmatism pulses is negligible in geological sense, no more than 5 million years, yet it would be wrong to postulate a continuous rather than a discrete magmatic cycle to 20 million years long. Belonging to an older group may be of metallogenic significance, especially in the recognition of a large-scale assimilation of ore components from enclosing rocks. In the second scenario, a “younger” group of intrusions injects into the association of enclosing sedimentary and metamorphic rocks already depleted in ore and fluid components. To understand the problem of sulphide ore origin from the Norilsk district, of great interest is the experience of separation and dating of zircons directly from the ore material (Fig. 3a–c). These zircons must have a direct genetic relationship either to mineralization, or to the ore component source. The first results of dating zircons separated from rich sulphide ores of the Oktyabrsky deposit (sample CG-1319, 598.4 m) have revealed the presence of as many as eight agegroups of detrital

Isotope Chronology of Geological Processes

225

Fig. 2 Complex U–Pb isotope systematics of zircons obtained by local method of SIMS SHRIMP. As an example of presorting of two generations of zircons in rocks, a large data array is given (197 datings of SIMS SHRIMP on Norilsk-1 intrusion; rocks of Medvezhij Ruchej open pit); a diagram with Tera-Wasserburg concordia with all the results (without errors). Average value of 237 Ma has no geological meaning if there are several generations of zircon; b the same data as a histogram. Age is adjusted for common Pb204. Two clusters are distinguished; c and d two data clusters on Tera-Wasserburg diagrams (errors ellipses) with ages 251 Ma (interpreted as crystallization time of Norilsk-1 intrusive) and 228 Ma (postmagmatic recrystallization and formation process of metasomatic zircon)

zircons, corresponding to different carrier rock sources. No zircons synchronous to the crystallization time of silicate matrix of layered intrusions (approx. 250 Ma) have been identified. The youngest detrital zircons (minimum age of sedimentation) are Vendian, 620 Ma, prevailing, 1940 and 2750 Ma (20–25%), the rest are intermediate Proterozoic and Late Archean (1550, 1660, 1860, 2050, and 2650 Ma). It is noteworthy that detrital zircons separated from Igarka copper sandstone (sample I-1) and quartz geode with native copper (sample Kum-1) have very similar

226

O. Petrov et al.

Isotope Chronology of Geological Processes

227

JFig. 3 Typical zircons from ores (a–c) and magmatic rocks of Cretaceous age (d) in Norilsk

Region. Figures—concordant U–Pb age of zircons (Ma) and share of population (%). Diameter of circumferences (sampling points) 30 µm. a five age clusters of detritic zircons in cupriferous Igarka sandstones (sample I-1); b one age cluster of zircon from a quartz zeode with native Cu, Kumga R. (sample Kum-1); c eight age clusters of inherited zircons in rich cupriferous-noble metal ore of Oktyabrskoe deposit (sample KZ-1319, 599 m, gabbro-doleritic pyrrhotitechalcopyrite breccia); d magmatic zircons from gabbro-dolerites spatially conjugated with Maslovsky deposit (sample OM-32, 1,085 m, 152 Ma), and Krasnye Kamni basalts (sample N-2, 148 Ma)

ages (620, 710, 910, 1840, 2650, 2700 Ma), but with a predominance of the Vendian-Riphean material. This is one of the compelling and visual arguments in favour of a purely crustal origin, at least, for a substantial portion of ore components. Of particular note is that the expansion of geochronological studies in the Norilsk district in 2013–2014 enabled us to first discover signs of the presence of mafic intrusive rocks younger than the prevailing Triassic ones. Their main distribution area is around theMaslovskoye intrusion (15 km south of Norilsk), where the density of tectonic dislocations increases greatly. Zircons from gabbro-dolerite and basalt are very few, but have all the signs of crystallization from the melt and exhibit undisturbed isotope U–Pb system (Fig. 3d), which enables to assume reasonably manifestation of a magmatic event in the Norilsk ore district at the Jurassic and Cretaceous boundary. It is noteworthy that young basalts contain inherited zircons (about 40%) both of Paleozoic (280–350 Ma), and Proterozoic (1900– 2000 Ma) age reflecting the composition of intruded strata. Sampling locations for zircon separation and analytical data are given in Tables 4, 5 and 6. Table 4 Sites of taking 64 samples for distinguishing zircons in the Norilsk District (2012–2014) Sample

Rock

Oktyabrskoe deposit, western flank, boreholes ZF 13/18/19/21/30/31/43, KZ 931/1319 ZF 13 Gabbro-dolerite, sulph. (15%) ZF 13 (448) Coarse-grained olivinic gabbro, sulph. (15%) ZF 13 (474.9–475.5) Coarse-grained breccia, metasom., albite, gabbro, hornfels ZF 18 (402.5) Medium-grained olivinic dolerite, sulph. (3%) ZF 18 (409.2) Coarse-grained leucogabbro, sulph. (3%) ZF 18 (419.1) Medium-grained leucogabbro, metasom., sulph. (10%) ZF 18 (437.2) Medium-grained leucogabbro, sulph. (1%) ZF 18 (450) Coarse-grained olivinic gabbro, sulph. (1%) ZF 18 (460.9) Coarse-grained olivinic dolerite, sulph. (1%) ZF 18 (471) Pyrox. hornfels, sulph. (5%) ZF 19 (429.7) Olivinic gabbro, sulph. (3%) ZF 19 (445) Coarse-grained metagabbro, sulph. (5%) ZF 19 (449) The same (continued)

228

O. Petrov et al.

Table 4 (continued) Sample

Rock

ZF 19 (479.1) Pl.-porphyr. coarse-grained olivinic dolerite, sulph. (1%) ZF 19 (488.6) Pl.-porphyr. coarse-grained olivinic dolerite, sulph. (1%) ZF 21 Medium-grained gabbro-dolerite, carb. ZF 21 (446.0–446.4) Coarse-grained leucogabbro, sulph. (5%) ZF 21 (457.6–457.9) Coarse-grained leucogabbro, sulph. (1%) ZF 21 (465.0–465.6) Medium-grained dolerite, sulph. (1%) ZF 21 (472.8–473.1) Pyrox. hornfels, sulph. (1%) ZF 30 (378.7) Olivinic pyrox. leucogabbro, sulph. (5%), carb. ZF 31 (539.8) Hornfels, coarse-grained leucogabbro, sulph. (1%) ZF 43 (625.5) Fine-grained dolerite, sulph. (1%) KZ 931 (616–622) Pl. wehrlite, pyrox. olivinic sulph. KZ 1319 (598.4) Rich sulph. Ores Oktyabrskoe deposit, central part, boreholes PT 2, KZ 981/1112 PT 2 Gabbro-dolerite, sulph. PT 2 (1368.4) Medium-grained dolerite, sulph. (3%) PT 2 (1371.2–1371.8) The same PT 2 (1415) Olivinic pyrox. gabbro-dolerite,sulph. (2%) PT 2 (1419.1) Coarse-grained pl. wehrlite, sulph. (5%) PT 2 (1423) Coarse-grained olivinic leucogabbro, sulph. (1%) PT 2 (1425) Medium-grained Pl. wehrlite, sulph. (10%) PT-2 (1438.7–1439.3) Medium-grained olivinic pyrox. pl. wehrlite, sulph. (15%) KZ 981 Medium-grained gabbrodolerite KZ 981(1126.3–1126.9) Medium-grained olivinic pyrox. gabbro, sulph. (1%) KZ 1112 (1098.4) Sulph. ore in feldspar rocks, hornfels Oktyabrskoe deposit, southern flank, boreholes KZ 361bis/1084 KZ 361bis Medium-grained pyrox. gabbrodolerite KZ 1084 (1150.1) Gabbrodolerite, gabbro, hornfels. sulph. Talnakh deposit KZ 774 Olivinic gabbro KZ 774 (1023) Medium-grained olivinic dolerite, sulph. (1%) KZ 774 (1029) Medium-grained olivinic dolerite, sulph. (10%) KZ 774 (1032.4–1033.0) Medium-grained wehrlite, sulph. (5%), anhydride Maslovsky deposit, boreholes OM 10/32/123 OM 10 (1061) Medium-grained olivinic pyrox. pl. wehrlite, sulph. (5%) OM 10 (1068) The same OM 32 (1084.8) Medium-grained olivinic gabbro, sulph. (5%) OM 123 (1005.6) Medium-grained olivinic gabbro, sulph. (1%) OM 123 (1033.7) Medium-grained olivinic pyrox. pl. wehrlite, sulph. (5%) Zub-Marksheidersky deposit MP 25 KZ (37.8) Coarse-grained olivinic metagabbro, sulph. (15%) (continued)

Isotope Chronology of Geological Processes

229

Table 4 (continued) Sample Chernogorsk deposit 12 N 18 12 N 19A 12 N 19B 12 N 21 MP 2 206 fg Listvyanka R. area 12 N 05 12 N 07 12 N 08 Krasnye Kamni area N 2/N 2 N3 Vologochan area, Bh. OV 28 OV 28 (703) OV 28 (711) OV 28 (827) Burkan M. area 657 2b Host rocks I1 KYM 1

Rock Coarse-grained metagabbro, sulph. (10%) (P) Medium-grained metagabbro, sulph. (5%) (T1) Coarse-grained metaleucogabbro, albite (T1) Hornfels after qu. feldspath. sandstone (Yu) (sulph. (1%) Medium-grained olivinic gabbro, sulph. (1%) (T2) Basalt, Syverma (T1) area Leucogabbro (Yu) Basalt, Tuklonskaya (P) area Basalt (Yu) Basalt Coarse-grained gabbro, sulph. (3%) The same Coarse-grained olivinic gabbro, sulph. (5%) Coarse-grained olivinic dolerite, sulph. (M) Cupriferous sandstone, Igarka Qu. nodule with copper

Table 5 Sites of taking 72 samples for distinguishing zircons in Norilsk and Taimyr Districts (2005–2007) Sample Norilsk intrusive, Medvezhij Ruchej, N/N 1 3 N16 N 1 7/8 N11 N12 Talnakh intrusive, Bh. OUG2 T2 T3 T5

Rock name Bh. MN2 Leucogabbro Olivinic gabbro Pl. wehrlite Gabbrodiorite Leucogabbro Diorite-pegmatite Gabbrodiorite Leucogabbro (continued)

230

O. Petrov et al.

Table 5 (continued) Sample

Rock name

T6 Olivinic gabbro T8 T 10 T 12 T 13 Pl. wehrlite, sulph. T 14 T 15 T 16 Troctolite, sulph. T 17 Pl. pyroxenite, sulph. T 18 Olivinic gabbro, sulph. T 22 Pl. wehrlite, sulph. Kharaelakh intrusive, Bh. KZ 844 844 1 Olivinic gabbro 844 6 Troctolite, sulph. 844 7 Pl. wehrlite 844 10 Troctolite Lower Talnakh intrusive, Bh. TG 31 31 1 Gabbro 31 3 Troctolite 31 7 Pl. wehrlite 31 9 Pl. olivinic gabbro 31 10 Pl. wehrlite 31 11 Troctolite 31 13 Pl. wehrlite 31 16 Troctolite Zub-Marksheidersky intrusive, Bh. 27 27 1 Metasomatite 27 3 27 4 27 5 Diorite 27 6 Olivinic gabbro 27 7 27 13 Troctolite sulph (10%) 27 14 Olivinic gabbro, sulph. Imangda intrusive, Bh. 4 43 Troctolite, sulph. (2%) 46 Pl. wehrlite sulph. (4%) 48 Troctolite, sulph. (2%) 49 Olivinic leucogabbro 4 10 Olivinic gabbro, sulph. (continued)

Isotope Chronology of Geological Processes Table 5 (continued) Sample

Rock name

Chernogorsk intrusive, Bh. MP 2bis CH 9 Olivinic gabbro CH 10 Troctolite, sulph. (2%) CH 11 Troctolite, sulph. (20%) South Pyasina intrusive, Bh.OV 25 25 2 Metasomatite 25 4 Olivinic gabbro, sulph. (10%) 25 9 Olivinic gabbro, sulph. (5%) 25 31/35 Troctolite, sulph. Vologochan intrusive, Bh.OV 29 29 5 Olivinic gabbro 29 9 Troctolite, sulph. 29 16 Troctolite, sulph. (15%) 29 17 Troctolite, sulph. Mikchangda intrusive, Bh. MD-48 48 18 Olivinic gabbro 48 25(9) Troctolite 48 30 Binyuda intrusive, Bh. C1 C1 4 3 Troctolite Dyumptalej intrusive, Bh. TP 43 43 27 Gabbro Lower Norilsk intrusive, Bh. NP 37 37 12 Olivinic gabbro 37 23 Pl. wehrlite Zelenaya Griva intrusive, Bh. F 233 233 2 Olivinic gabbro 233 4 Metasomatite 233 6 Pl. wehrlite 233 7 Troctolite Kruglogorsky intrusive, Bh. MP 2bis К9 Olivinic gabbro Morongo intrusive, Ruinnaya Mountain Ru2 Troctolite Daldykan intrusive, Bh. NP 37 37 34 Olivinic dolerite Oganer intrusive, Bh. MD 48 48 7 Olivinic dolerite Ergalakh intrusive, Bh. NP 37 37 52 Trachydolerite

231

0.12

0.22

ZF-13_5.1

ZF-13_6.1

ZF-13-474.9-475.5_1.1

0.52

10.71

0.01

ZF-18(402.5)_7.1

ZF-18(402.5)_3.2

ZF-18(402.5)_11.1

0.24

0.01

ZF-18(402.5)_1.1

ZF-18(402.5)_2.1

0.30

0.89

ZF-18(402.5)_3.1

ZF-18(402.5)_8.1

0.01

0.79

ZF-18(402.5)_5.1

ZF-18(402.5)_4.1

0.98

0.22

ZF-18(402.5)_5.2

ZF-18(402.5)_8.2

0.42

0.08

ZF-18(402.5)_14.1

ZF-18(402.5)_10.1

0.01

4.30

ZF-18(402.5)_6.1

ZF-18(402.5)_15.1

ZF 18 (402.5)

0.21

1.40

ZF-13-448.0_2.1

ZF 13 (474.9–475.5)

0.38

ZF-13-448.0_1.1

ZF 13 (448.0)

0.16

0.23

ZF-13_2.1

ZF-13_1.1

3.34

0.18

Pbc, %

ZF-13_3.1

206

ZF-13_4.1

ZF 13

Crater

1685

78

451

872

644

227

1031

811

380

681

447

863

491

546

583

205

1286

538

1739

2743

1134

937

1366

554

U, ppm

2329

61

459

910

617

258

978

783

816

641

452

871

323

626

635

137

3319

1066

1509

10,622

3626

3734

3194

192

Th, ppm

Th/238U

1.43

0.81

1.05

1.08

0.99

1.17

0.98

1.00

2.22

0.97

1.05

1.04

0.68

1.18

1.12

0.69

2.67

2.05

0.90

4.00

3.30

4.12

2.42

0.36

232

Pb*, ppm

59.3

2.4

11.1

19.9

14.7

5.2

23.3

18.2

8.4

15.0

9.9

18.9

10.6

12.3

12.5

63.3

47.4

19.0

61.5

96.6

39.8

32.8

47.4

12.3

206

258.7

206.0

181.4

169.1

168.7

167.9

167.1

165.1

164.3

163.1

162.8

161.8

159.8

159.6

158.9

1974.0

267.1

258.8

259.5

258.7

257.4

257.0

254.9

172 920 251

±3.7 ±15.0 ±4.5

122 121

±3.1 ±3.1

130 146

±3.0 ±3.8

226 207

±3.2 ±3.1

166 121

±3.2 ±3.0

211 135

±3.1 ±2.9

175 221

±3.0 ±3.5

1978

–

±18.0

–

±2.6

263 227

±3.7 ±3.8 ±2.7

246 218

±3.8 ±3.8

55 257

±2.9

Pb*/235U

±30

±1600

±150

±49

±87

0.289

0.310

0.195

0.178

0.177

0.176 0.178

±87

0.180

0.180

0.171

0.174

0.171

0.174

0.175

0.171

6

0.299

0.278

0.287

0.291

0.284

0.287

0.286

0.162

207

±250

±170

±80

±81

±210

±62

±120

±420

±66

±24

–

–

±50

±35

±55

±70

±46

±350

207 Pb*/206Pb* Age

±3.8

Pb*/238U Age

158.9

206

2.2

79.0

6.7

2.8

4.1

11.0

4.1

7.8

4.0

3.9

9.0

3.2

5.7

18.0

3.4

1.7

5.8

4.7

2.7

2.1

2.8

3.4

2.5

15.0

±%

0.0410

0.0325

0.0285

0.0266

0.0265

0.0264

0.0263

0.0259

0.0258

0.0256

0.0256

0.0254

0.0251

0.0251

0.0250

0.3583

0.0423

0.0410

0.0411

0.0409

0.0407

0.0407

0.0403

0.0250

Pb*/238U

206

0.803

0.095

0.309

0.660

0.454

0.213

0.446

0.245

0.491

0.476

0.221

0.569

0.343

0.121

0.556

0.620

0.176

0.229

0.570

0.699

0.527

0.440

0.598

0.122

КК

(continued)

1.8

7.5

2.1

1.8

1.9

2.3

1.8

1.9

2.0

1.9

2.0

1.8

1.9

2.2

1.9

1.0

1.0

1.1

1.5

1.5

1.5

1.5

1.5

1.8

±%

Table 6 Summary of results of U–Pb SIMS SHRIMP isotope analyzes of zircons from 72 samples of 2005–2007 from rocks and ores of Norilsk and Taimyr Districts and 64 samples of 2012–2014

232 O. Petrov et al.

0.15

ZF-18(402.5)_13.1

0.51

0.01

ZF-18(409.2)_12.1

ZF-18(409.2)_13.1

0.26

0.01

ZF-18(419.1)_6.1

ZF-18(419.1)_1.1

0.39

0.53

0.47

ZF-18(437.2)_1.1

ZF-18(437.2)_1.2

ZF-18(437.2)_2.1

ZF 18 (437.2)

2.29

0.06

ZF-18(419.1)_2.1

ZF-18(419.1)_5.1

0.08

0.46

ZF-18(419.1)_4.1

ZF-18(419.1)_3.1

ZF 18 (419.1)

0.34

0.01

ZF-18(409.2)_10.1

ZF-18(409.2)_11.1

0.19

0.51

ZF-18(409.2)_8.1

ZF-18(409.2)_9.1

0.06

0.66

ZF-18(409.2)_6.1

ZF-18(409.2)_7.1

0.06

0.61

ZF-18(409.2)_5.1

ZF-18(409.2)_5.2

0.03

0.85

ZF-18(409.2)_3.1

ZF-18(409.2)_4.1

0.90

0.01

ZF-18(409.2)_1.1

ZF-18(409.2)_2.1

ZF 18 (409.2)

0.01

0.09

Pbc, %

ZF-18(402.5)_11.2

206

ZF-18(402.5)_9.1

Crater

Table 6 (continued)

534

758

985

2

920

3550

638

1678

1992

729

437

838

1500

1464

748

250

2811

1443

2611

623

1893

636

873

3913

2094

2708

U, ppm

177

442

589

1

498

8189

2057

2894

3877

1000

823

1558

2937

3334

1503

451

8693

4305

10,671

2946

5226

1946

4397

5874

2108

5023

Th, ppm

Th/238U

0.34

0.60

0.62

0.03

0.56

2.38

3.33

1.78

2.01

1.42

1.95

1.92

2.02

2.35

2.08

1.86

3.20

3.08

4.22

4.89

2.85

3.16

5.21

1.55

1.04

1.92

232

Pb*, ppm

18.8

26.6

34.7

0.5

37.9

128.0

23.5

59.5

70.0

24.8

14.2

28.1

52.3

51.7

25.7

8.3

94.9

50.1

91.4

21.9

66.2

21.3

30.9

148.0

74.0

95.3

206

257.3

256.5

258.0

2055

301.2

265.7

264.4

259.4

258.2

249.9

238.8

247.1

255.5

258.2

252.2

242.2

248.4

253.7

257.5

256.3

257.2

246.6

257.8

277.3

259.5

239 370 310

±2.9 ±3.1

254 2191

±3.4 ±98.0

±3.0

235 202

±4.0 ±2.7

268 234

±2.4

153 346

±4.7 ±4.6

±2.5

298 216

±4.6 ±4.5

339 130

±4.6 ±4.8

238 123

±4.4 ±5.0

205 277

±4.4 ±4.8

303 215

±4.4 ±4.8

306 242

±4.6

219

±5.3

±4.4

248 245

±4.5

Pb*/235U

0.294 ±76

±110

±110

±100

±140

0.295

0.302

0.287

7.100

0.338

0.291

±370 ±49

0.288

0.291

0.291

0.256

0.272

0.292

0.274

0.293

0.256

0.276

0.287

0.282

0.282

0.294

0.274

0.295

0.306

0.289

0.289

207

±77

±43

±49

±150

±49

±61

±100

±67

±190

±30

±99

±32

±140

±28

±47

±120

±55

±43

±29

207 Pb*/206Pb* Age

±4.5

Pb*/238U Age

258.9

206

5.1

4.8

4.6

9.8

3.5

2.3

16.0

3.5

2.1

2.9

6.8

2.8

3.2

4.7

3.5

8.5

2.2

4.7

2.2

6.3

2.1

2.7

5.7

3.1

2.6

2.2

±%

0.0407

0.0406

0.0408

0.3750

0.0478

0.0421

0.0419

0.0411

0.0409

0.0395

0.0377

0.0391

0.0404

0.0409

0.0399

0.0383

0.0393

0.0402

0.0408

0.0406

0.0407

0.0390

0.0408

0.0440

0.0411

0.0410

Pb*/238U

206

0.240

0.246

0.248

0.569

0.329

0.440

0.095

0.279

0.443

0.655

0.296

0.657

0.565

0.404

0.536

0.248

0.812

0.405

0.784

0.303

0.821

0.665

0.317

0.638

0.685

0.816

КК

(continued)

1.2

1.2

1.1

5.6

1.1

1.0

1.5

1.0

0.9

1.9

2.0

1.9

1.8

1.9

1.9

2.1

1.8

1.9

1.7

1.9

1.8

1.8

1.8

2.0

1.8

1.8

±%

Isotope Chronology of Geological Processes 233

0.19

390

0.01

0.57

0.01

ZF18_450_13.1

ZF18_450_14.1

ZF18_450_15.1

0.22

0.01

ZF18_450_11.1

ZF18_450_12.1

0.31

0.25

ZF18_450_9.1

ZF18_450_10.1

947

3.58

0.91

ZF18_450_8.1

ZF18_450_8.2

539

262

268

103

127

244

223

1651

1720

0.01

0.15

ZF18_450_6.1

199

2174

351

147

26

288

640

1208

693

ZF18_450_7.1

0.85

0.53

ZF18_450_4.2

ZF18_450_5.1

0.01

1.58

ZF18_450_3.1

ZF18_450_4.1

0.32

0.01

ZF18_450_1.1

ZF18_450_2.1

ZF 18 (450)

ZF-18(437.2)_11.1

1539

0.13

0.31

ZF-18(437.2)_9.1

ZF-18(437.2)_10.1

1523

0.01

0.09

ZF-18(437.2)_7.1

ZF-18(437.2)_8.1

859

693

0.01

0.18

ZF-18(437.2)_5.1

1704

720

U, ppm

ZF-18(437.2)_6.1

0.33

0.01

Pbc, %

ZF-18(437.2)_3.1

206

ZF-18(437.2)_4.1

Crater

Table 6 (continued)

258

422

116

140

293

114

236

755

1122

2436

1455

216

595

344

230

21

383

360

800

754

1033

542

507

448

1733

290

Th, ppm

Th/238U

1.02

1.63

1.17

1.14

1.24

0.53

0.63

0.82

0.70

1.46

2.79

1.12

0.28

1.01

1.62

0.85

1.37

0.58

0.68

0.51

0.70

0.81

0.76

0.54

1.05

0.42

232

Pb*, ppm

8.7

8.7

3.4

4.3

18.9

36.8

13.0

32.7

62.7

60.5

17.6

6.6

79.7

11.8

4.8

0.8

9.8

22.4

42.2

53.7

54.1

24.2

23.8

30.7

59.8

24.7

206

246.6

238.3

243.4

247.6

554.0

1128.0

244.1

252.2

269.1

258.4

240.9

244.6

267.0

244.9

242.9

235.7

249.4

256.6

256.0

256.2

260.8

257.1

252.3

262.5

258.2

267 145 392

±4.4 ±3.1 ±3.7

384 378

±6.0 ±4.0

23 1294

±2.7 ±11.0

43 215

±2.9 ±2.6

246 323

±2.4 ±2.9

160 201

±2.2 ±3.4

225 479

±3.6 ±3.5

123 684

±3.0

237

±2.9

±7.5

255 154

±2.6 ±2.7

276 246

±2.9 ±2.6

232 295

±2.8 ±2.8

227 227

±2.8

Pb*/235U

0.247 ±75

±150

±160

±140

±110

0.293

0.254

0.274

0.292

0.672

2.217

±110 ±35

0.277

0.276

0.298

0.268

0.267

0.287

0.303

0.268

0.320

0.264

0.285

0.274

0.287

0.291

0.291

0.287

0.291

0.286

0.278

207

±110

±200

±51

±71

±150

±89

±200

±110

±230

±110

±110

±69

±46

±52

±54

±65

±51

±35

±89

207 Pb*/206Pb* Age

±2.6

Pb*/238U Age

251.6

206

6.7

6.9

6.2

5.4

3.5

2.1

4.8

5.0

8.5

2.5

3.3

6.8

3.9

9.3

5.1

11.0

5.0

5.1

3.1

2.3

2.5

2.6

3.1

2.5

1.8

4.0

±%

0.0390

0.0377

0.0385

0.0392

0.0897

0.1913

0.0386

0.0399

0.0426

0.0409

0.0381

0.0387

0.0423

0.0387

0.0384

0.0372

0.0394

0.0406

0.0405

0.0406

0.0413

0.0407

0.0399

0.0416

0.0409

0.0398

Pb*/238U

206

0.227

0.190

0.295

0.305

0.322

0.503

0.235

0.209

0.129

0.452

0.315

0.208

0.220

0.157

0.302

0.292

0.247

0.226

0.337

0.456

0.418

0.433

0.372

0.448

0.554

0.286

КК

(continued)

1.5

1.3

1.8

1.6

1.1

1.1

1.1

1.0

1.1

1.1

1.0

1.4

0.9

1.5

1.5

3.2

1.2

1.2

1.1

1.0

1.0

1.1

1.1

1.1

1.0

1.2

±%

234 O. Petrov et al.

0.05

0.12

ZF-18(460.3–460.9)_8.1

ZF-18(460.3–460.9)_9.1

399

0.08

0.10

ZF18_471_9.1

ZF18_471_10.1

0.40

0.45

0.54

0.39

ZF-19-429.7_1.1

ZF-19-429.7_2.1

ZF-19-429.7_3.1

ZF-19-429.7_4.1

ZF 19 (429.7)

776

0.10

0.12

ZF18_471_7.1

ZF18_471_8.1

526

480

576

439

901

1028

865

1039

0.19

0.22

ZF18_471_5.1

598

379

180

2777

1967

1331

949

865

1113

1158

1076

1410

932

2799

978

813

U, ppm

ZF18_471_6.1

0.14

0.21

ZF18_471_3.1

ZF18_471_4.1

0.06

0.33

ZF18_471_1.1

ZF18_471_2.1

ZF 18 (471)

0.18

0.08

ZF-18(460.3–460.9)_7.1

ZF-18(460.3–460.9)_7.2

0.09

0.10

ZF-18(460.3–460.9)_6.1

ZF-18(460.3–460.9)_6.2

0.14

0.08

ZF-18(460.3–460.9)_4.1

ZF-18(460.3–460.9)_5.1

0.07

0.21

ZF-18(460.3–460.9)_2.2

ZF-18(460.3–460.9)_3.1

0.09

0.01

Pbc, %

ZF-18(460.3–460.9)_1.1

206

ZF-18(460.3–460.9)_2.1

ZF 18 (460.9)

Crater

Table 6 (continued)

563

498

902

500

772

214

585

1026

638

1008

436

224

58

4286

2388

6528

3889

3309

3105

5285

5623

6076

3220

6193

1354

1091

Th, ppm

Th/238U

1.10

1.07

1.62

1.18

0.89

0.56

0.78

1.03

0.76

1.00

0.75

0.61

0.33

1.60

1.25

5.07

4.23

3.95

2.88

4.71

5.40

4.45

3.57

2.29

1.43

1.39

232

Pb*, ppm

18.0

16.7

20.4

15.3

31.8

123.0

26.6

34.7

29.3

35.8

20.9

112.0

52.1

99.3

72.3

47.4

33.2

30.0

39.5

40.6

37.7

50.4

32.7

103.0

35.2

29.6

206

250.2

254.9

259.7

255.2

259.2

1974.0

251.6

248.0

248.9

253.2

256.0

1906.0

1868.0

262.7

269.8

261.7

256.8

254.9

260.5

257.3

257.8

262.3

257.5

269.6

264.7

177 183 238 169

±3.2 ±3.2 ±3.1

1894 244

±18.0 ±2.5

±3.1

238 219

±2.6 ±2.4

203 228

±2.6 ±2.3

1903 207

±15.0 ±2.9

211 1859

±2.1

255 240

±4.3 ±5.3

±17.0

263 249

±4.6 ±4.4

224 288

±4.4 ±4.5

310 251

±4.4 ±4.4

251 198

±4.4 ±4.3

264 264

±4.3

±120

±130

±120

±120

±51

±14

±57

±47

±74

±56

±73

±16

±28

±39

±47

±33

±46

±52

±47

±46

±37

±55

±57

±28

±32

±46

207 Pb*/206Pb* Age

±4.4

Pb*/238U Age

267.4

206

Pb*/235U

0.270

0.283

0.282

0.276

0.289

5.726

0.277

0.276

0.275

0.277

0.281

5.527

5.270

0.289

0.301

0.293

0.287

0.286

0.296

0.284

0.288

0.301

0.281

0.302

0.298

0.301

207

5.3

6.0

5.2

5.4

2.4

1.3

2.6

2.3

3.4

2.6

3.3

1.3

1.9

1.9

2.9

2.2

2.7

2.9

2.7

2.6

2.4

3.0

3.0

2.1

2.2

2.6

±%

0.0396

0.0403

0.0411

0.0404

0.0410

0.3583

0.0398

0.0392

0.0394

0.0401

0.0405

0.3441

0.3361

0.0416

0.0427

0.0414

0.0406

0.0403

0.0412

0.0407

0.0408

0.0415

0.0408

0.0427

0.0419

0.0424

Pb*/238U

206

0.241

0.216

0.235

0.239

0.401

0.806

0.372

0.464

0.284

0.402

0.351

0.731

0.565

0.445

0.702

0.759

0.661

0.636

0.656

0.658

0.738

0.577

0.570

0.813

0.772

0.629

КК

(continued)

1.3

1.3

1.2

1.3

1.0

1.1

1.0

1.1

1.0

1.1

1.2

0.9

1.1

0.8

2.0

1.7

1.8

1.9

1.8

1.7

1.7

1.7

1.7

1.7

1.7

1.6

±%

Isotope Chronology of Geological Processes 235

0.19

ZF-19-429.7_2.2

0.39

0.31

ZF-19-449_7.1

ZF-19-449_8.1

0.01

0.43

0.01

0.23

ZF-19-479.1_1.1

ZF-19-479.1_7.1

ZF-19-479.1_12.1

ZF-19-479.1_3.1

0.06

0.18

ZF-19-479.1_11.2

ZF-19-479.1_8.1

0.12

0.09

ZF-19-479.1_6.1

ZF-19-479.1_2.1

0.04

0.08

ZF-19-479.1_11.1

ZF-19-479.1_10.1

0.17

0.22

ZF-19-479.1_5.1

ZF-19-479.1_4.1

0.11

0.06

ZF-19-479.1_9.1

ZF-19-479.1_10.2

ZF 9 (479.1)

0.29

0.16

ZF-19-449_5.1

ZF-19-449_6.1

0.30

0.75

ZF-19-449_3.1

ZF-19-449_4.1

0.72

0.61

ZF-19-449_1.1

ZF-19-449_2.1

ZF 19 (449)

0.81

0.09

ZF-19-445_1.1

ZF-19-445_2.1

ZF 19 (445)

0.16

0.14

Pbc, %

ZF-19-429.7_1.2

206

ZF-19-429.7_1.3

Crater

Table 6 (continued)

2767

5948

2619

2688

2280

2534

5307

1294

1621

2243

2148

2224

2176

966

1408

726

1595

1093

995

995

403

257

1175

1642

925

2705

1984

U, ppm

3452

10,275

5457

4865

2945

3523

14,637

3081

1497

2968

4350

2997

4151

1748

2144

665

1660

1396

2163

3253

793

350

3069

3642

1719

2730

1080

Th, ppm

Th/238U

1.29

1.78

2.15

1.87

1.33

1.44

2.85

2.46

0.95

1.37

2.09

1.39

1.97

1.87

1.57

0.95

1.08

1.32

2.24

3.38

2.03

1.41

2.70

2.29

1.92

1.04

0.56

232

Pb*, ppm

107.0

225.0

94.4

96.2

81.4

90.1

188.0

45.7

57.0

78.7

74.9

77.3

75.0

32.9

49.8

25.9

57.4

38.0

36.5

36.8

14.5

9.0

41.8

60.9

31.7

96.4

70.5

206

281.9

278.1

263.9

263.0

262.1

261.3

260.3

259.5

258.5

258.0

255.9

255.2

253.4

250.3

259.3

261.5

264.2

254.8

267.1

271.0

262.8

254.1

261.4

270.2

251.7

261.8

265 272 277 187

±2.2 ±2.5 ±3.2 ±3.5

252 228

±3.0 ±3.0

293 228

±2.5 ±3.0

269 226

±2.6 ±2.6

245 311

±2.8 ±2.9

223 244

±2.7

169 302

±4.4 ±4.3

±2.5

190 259

±4.3 ±4.4

167 267

±4.7 ±4.6

338 125

±4.9 ±4.9

219 303

±4.5

363

±2.8

±4.3

249 202

±2.6

Pb*/235U

0.296 ±33

±61

±21

±59

±25

±55

0.307

0.315

0.298

0.296

0.290

0.292

0.288

±46 ±27

0.286

0.291

0.294

0.285

0.282

0.276

0.297

0.282

0.297

0.277

0.301

0.292

0.278

0.295

0.299

0.298

0.295

0.287

0.292

207

±41

±40

±52

±46

±34

±63

±58

±78

±39

±64

±110

±82

±190

±150

±49

±110

±63

±40

±48

207 Pb*/206Pb* Age

±2.6

Pb*/238U Age

260.9

206

2.9

1.5

2.8

1.4

2.7

1.9

1.6

2.2

2.1

2.0

2.6

2.3

1.8

2.9

3.1

3.8

2.4

3.2

4.9

3.9

8.3

6.9

2.7

4.9

3.0

2.0

2.3

±%

0.0447

0.0441

0.0418

0.0417

0.0415

0.0414

0.0412

0.0411

0.0409

0.0408

0.0405

0.0404

0.0401

0.0396

0.0411

0.0414

0.0419

0.0403

0.0423

0.0429

0.0416

0.0402

0.0414

0.0428

0.0398

0.0414

0.0413

Pb*/238U

206

0.433

0.798

0.351

0.614

0.445

0.636

0.707

0.446

0.499

0.507

0.453

0.487

0.564

0.373

0.549

0.459

0.701

0.527

0.354

0.450

0.230

0.286

0.616

0.348

0.373

0.508

0.440

КК

(continued)

1.3

1.2

1.0

0.9

1.2

1.2

1.2

1.0

1.0

1.0

1.2

1.1

1.0

1.1

1.7

1.7

1.7

1.7

1.7

1.8

1.9

2.0

1.7

1.7

1.1

1.0

1.0

±%

236 O. Petrov et al.

0.08

0.08

0.11

0.05

0.18

0.01

0.01

4.07

0.15

0.09

0.14

ZF-19-488.6_5.1

ZF-19-488.6_6.1

ZF-19-488.6_7.1

ZF-19-488.6_8.1

ZF-19-488.6_10.1

ZF-19-488.6_9.1

ZF-19-488.6_2.1

ZF-19-488.6_1.1

ZF-19-488.6_4.1

ZF-19-488.6_7.2

0.06

0.06

0.08

0.08

0.10

ZF-21_3.1

ZF-21_5.1

ZF-21_4.2

ZF-21_4.1

ZF-21_2.1

5.01

ZF-21-446.0–446.4_1.2

0.77

0.24

0.32

0.05

1.57

ZF-21-457.6–457.9_4.1

ZF-21-457.6–457.9_3.2

ZF-21-457.6–457.9_2.1

ZF-21-457.6–457.9_3.1

ZF-21-457.6–457.9_1.1

ZF 21 (457.6–457.9)

0.46

ZF-21-446.0–446.4_1.1

ZF 21 (446.0–446.4)

0.31

ZF-21_1.1

ZF 21

0.08

ZF-19-488.6_3.2

Pbc, %

206

ZF-19-488.6_3.1

ZF 19 (488.6)

Crater

Table 6 (continued)

1286

3092

2840

2100

2091

519

563

4760

3600

2361

2917

1505

662

5139

5616

3770

1651

4905

2512

2988

4110

2635

2759

1099

631

U, ppm

4226

6480

6670

5438

2516

1072

1134

14,380

7635

5864

4213

1846

639

13,273

13,447

6277

2961

10674

6262

8672

12,133

5801

5444

3866

2518

Th, ppm

3.39

2.17

2.43

2.68

1.24

2.13

2.08

3.12

2.19

2.57

1.49

1.27

1.00

2.67

2.47

1.72

1.85

2.25

2.58

3.00

3.05

2.28

2.04

3.63

4.12

Th/238U

232

49.4

119.0

106.0

79.2

78.0

20.2

20.4

181.0

137.0

88.3

107.0

52.8

11.1

211.0

227.0

146.0

64.6

188.0

94.5

113.0

155.0

98.9

102.0

41.2

22.1

Pb*, ppm

206

277.4

283.1

273.3

276.2

272.0

270.9

265.0

278.9

278.4

274.5

269.6

257.9

123.6

300.0

296.3

283.2

275.5

281.7

276.4

277.4

277.2

275.5

271.5

275.2

257.5

– – – – –

±3.0 ±2.0 ±3.0 ±2.0

–

±4.2 ±3.0

–

±2.8

265

211

±3.2

±3.0

236

±2.5

269

251

±2.2

±3.0

304

±2.9

285

241

±2.8

±3.0

282

±3.1

266

240

±2.8

±3.0

235

±2.8

260

247

±3.1

75

276

±2.7

±3.1

235

±1.8

251

±2.4

–

–

–

–

–

–

–

±23

±26

±39

±26

±35

±120

±38

±28

±39

±230

±27

±39

±40

±30

±39

±40

±48

±71

207 Pb*/206Pb* Age

±2.8

Pb*/238U Age

206

0.388

0.325

0.309

0.305

0.292

0.365

0.302

0.314

0.314

0.312

0.304

0.289

0.127

0.331

0.330

0.317

0.316

0.314

0.314

0.309

0.308

0.308

0.307

0.306

0.288

Pb*/235U

207

13.0

1.9

2.5

2.7

3.6

14.0

5.0

1.5

1.6

2.0

1.6

2.0

5.2

2.0

1.5

1.9

10.0

1.5

2.0

2.0

1.6

2.1

2.0

2.3

3.3

±%

0.0440

0.0449

0.0433

0.0438

0.0431

0.0429

0.0450

0.0442

0.0441

0.0435

0.0427

0.0408

0.0194

0.0476

0.0470

0.0449

0.0437

0.0447

0.0438

0.0440

0.0440

0.0437

0.0430

0.0436

0.0408

Pb*/238U

206

0.074

0.580

0.305

0.403

0.294

0.110

0.215

0.747

0.703

0.556

0.708

0.620

0.283

0.564

0.584

0.424

0.103

0.663

0.560

0.515

0.621

0.555

0.502

0.390

0.335

КК

(continued)

0.9

1.1

0.8

1.1

1.1

1.6

1.1

1.1

1.1

1.1

1.1

1.2

1.5

1.1

0.9

0.8

1.1

1.0

1.1

1.0

1.0

1.1

1.0

0.9

1.1

±%

Isotope Chronology of Geological Processes 237

0.13

0.12

0.05

0.02

ZF-21-465.0–465.6_2.1

ZF-21-465.0–465.6_2.2

ZF-21-465.0–465.6_4.1

0.43

ZF-21-472.8-473.1_1.2

0.37

0.22

0.46

0.01

0.08

0.22

0.18

0.01

0.01

ZF-30_3.1

ZF-30_10.1

ZF-30_5.1

ZF-30_7.1

ZF-30_2.1

ZF-30_4.1

ZF-30_9.1

ZF-30_8.1

ZF-30_6.1

0.55

0.93

1.78

1.20

0.98

0.69

0.67

ZF-31_1.1

ZF-31_2.1

ZF-31_3.1

ZF-31_4.1

ZF-31_5.1

ZF-31_6.1

ZF-31_7.1

ZF 31 (539.8)

0.19

ZF-30_1.1

ZF 30 (578.7)

0.23

ZF-21-472.8–473.1_1.1

ZF 21 (472.8–473.1)

2.33

ZF-21-465.0–465.6_1.1

Pbc, %

206

ZF-21-465.0–465.6_3.1

ZF 21 (465.0–465.6)

Crater

Table 6 (continued)

511

443

714

817

306

467

653

293

53

324

95

249

472

276

486

459

859

346

282

1131

8096

6030

1957

477

U, ppm

309

205

387

755

140

323

194

188

81

179

58

224

1333

108

269

317

1167

62

69

5

9100

4458

3442

249

Th, ppm

0.62

0.48

0.56

0.96

0.47

0.71

0.31

0.66

1.58

0.57

0.63

0.93

2.92

0.40

0.57

0.71

1.40

0.19

0.26

0.01

1.16

0.76

1.82

0.54

Th/238U

232

8.7

7.6

12.2

13.8

5.29

8.16

11.0

95.7

15.0

90.7

12.7

33.1

53.9

17.1

25.0

20.6

15.0

20.1

18.3

343.0

322.0

230.0

33.7

8.07

Pb*, ppm

206

124.8

127.1

125.9

124.3

126.3

128.5

125.1

2075.0

1828.0

1815.0

929.0

927.0

805.4

447.6

375.0

326.5

129.6

419.2

468.4

1950.0

291.6

279.8

127.6

122.8

1939.7

±17.0

– 586 34

±1.9 ±1.8

2095

±22.0

298

1840

±29.0

±1.8

1827

±20.0

±1.8

926

±14.0

–

901

±11.0

±2.3

782

±9.3

223

412

±6.6

8

345

±4.7

±2.0

289

±4.2

±1.7

154

±1.7

–

–

±2.8

–

–

±2.6

±3.9

–

±4.5

–

±1.4

±160

±190

–

±260

–

±310

±130

±15

±39

±20

±67

±38

±29

±93

±70

±97

±83

–

–

±9

–

–

–

–

207 Pb*/206Pb* Age

±1.8

Pb*/238U Age

206

0.126

0.163

0.117

0.140

0.116

0.140

0.125

6.800

5.090

5.008

1.494

1.474

1.197

0.545

0.441

0.373

0.138

0.518

0.576

5.791

0.327

0.317

0.132

0.13

Pb*/235U

207

6.9

9.0

8.9

11.0

16.0

13.0

5.4

1.5

2.8

1.7

3.6

2.2

1.9

4.4

3.4

4.4

3.8

3.9

3.3

1.1

1.3

1.6

2.8

18.0

±%

0.0196

0.0199

0.0197

0.0195

0.0198

0.0201

0.0196

0.3798

0.3279

0.3253

0.1550

0.1547

0.1331

0.0719

0.0599

0.0520

0.0203

0.0672

0.0754

0.3533

0.0463

0.0444

0.020

0.0192

Pb*/238U

206

0.209

0.170

0.161

0.128

0.110

0.115

0.250

0.835

0.647

0.752

0.450

0.581

0.661

0.344

0.389

0.299

0.355

0.250

0.304

0.892

0.758

0.600

0.391

0.081

КК

(continued)

1.4

1.5

1.4

1.4

1.8

1.6

1.3

1.3

1.8

1.3

1.6

1.3

1.2

1.5

1.3

1.3

1.3

1.0

10.0

1.0

1.0

1.0

1.1

1.5

±%

238 O. Petrov et al.

0.57

0.74

ZF43.2.2

0.11

0.01

0.17

0.01

0.05

0.26

0.01

0.13

0.06

0.06

0.06

KZ931_2.1

KZ931_3.1

KZ931_4.1

KZ931_5.1

KZ931_6.1

KZ931_7.1

KZ931_8.1

KZ931_9.1

KZ931_10.1

KZ931_11.1

KZ931_12.1

0.29

0.01

0.74

0.03

0.01

0.50

0.01

0.03

0.18

0.26

0.01

KZ-13-19_12.1

KZ-13-19_1.1

KZ-13-19_7.1

KZ-13-19_8.1

KZ-13-19_7.2

KZ-13-19_9.1

KZ-13-19_2.1

KZ-13-19_11.1

KZ-13-19_11.2

KZ-13-19_5.2

KZ-13-19_5.1

KZ 1319 (626.8)

0.03

KZ931_1.1

KZ 931 (616–622)

0.01

ZF43.2.1

Pbc, %

206

ZF43.1.1

ZF 43 (625.5)

Crater

Table 6 (continued)

48

81

132

127

12

31

49

304

43

94

325

936

626

325

1438

449

428

1082

772

788

335

154

545

4683

5023

5236

U, ppm

56

133

55

51

17

46

42

178

29

76

111

758

663

1

1285

224

278

979

641

632

196

70

7

214

332

8072

Th, ppm

1.22

1.69

0.43

0.41

1.56

1.53

0.88

0.60

0.71

0.84

0.35

0.84

1.09

0.01

0.92

0.51

0.67

0.94

0.86

0.83

0.60

0.47

0.01

0.05

0.07

1.59

Th/238U

232

14.0

23.6

38.0

36.4

2.9

7.9

11.6

71.7

10.0

20.9

28.0

32.0

22.0

46.0

50.2

15.0

14.5

37.1

26.7

26.8

11.6

40.0

243.0

183.0

196.0

181.0

Pb*, ppm

206

1902.0

1871.0

1854.0

1852.0

1674.0

1659.0

1568.0

1562.0

1544.0

1491.0

615.0

251.1

257.8

983.0

256.5

245.4

248.1

252.3

254.7

249.9

254.0

1701.0

2691.0

285.1

284.4

254.2

1588 1660 1863 1843 1860 1868

±39.0 ±16.0 ±16.0 ±19.0 ±23.0

254

±3.6

1546

215

±3.8

±25.0

1009

±13.0

±20.0

213

±3.5

1540

205

±3.7

±12.0

289

±3.8

1536

216

±3.5

±22.0

266

±3.6

1455

231

±3.4

578

307

±3.8

±15.0

1724

±5.2

2693.2

364

±5.2

±28.0

412

±30.0

257

±5.0

±32

±33

±26

±20

±75

±68

5.410

5.280

5.176

5.227

4.170

3.970

3.643

3.613

±17 ±40

3.560

3.279

0.818

0.281

0.284

1.653

0.282

0.269

0.282

0.278

0.287

0.277

0.291

4.394

13.170

0.336

0.342

0.285

Pb*/235U

207

±79

±31

±66

±37

±45

±31

±39

±49

±66

±34

±36

±57

±53

±19

±6.6

±53

±44

±23

207 Pb*/206Pb* Age

±4.5

Pb*/238U Age

206

2.3

2.2

1.8

1.5

4.9

4.0

2.6

1.2

4.5

2.0

3.2

2.2

2.4

2.1

2.2

2.6

3.3

2.0

2.1

2.8

2.8

2.1

1.4

3.0

2.7

2.1

±%

0.3432

0.3367

0.3332

0.3328

0.2966

0.2935

0.2755

0.2741

0.2706

0.2602

0.1001

0.0397

0.0408

0.1646

0.0406

0.0388

0.0392

0.0399

0.0403

0.0395

0.0402

0.3019

0.5180

0.0452

0.0451

0.0402

Pb*/238U

206

0.619

0.544

0.565

0.662

0.547

0.425

0.560

0.682

0.354

0.572

0.280

0.670

0.610

0.691

0.643

0.584

0.474

0.697

0.676

0.492

0.549

0.871

0.960

0.619

0.676

0.879

КК

(continued)

1.4

1.2

1.0

1.1

2.7

1.7

1.4

0.0

1.6

1.1

0.9

1.4

1.5

1.4

1.4

1.5

1.5

1.4

1.4

1.4

1.5

1.9

1.4

1.9

1.8

1.8

±%

Isotope Chronology of Geological Processes 239

0.09

0.16

0.20

0.01

0.38

0.59

0.14

0.57

KZ-13-19_16.1

KZ-13-19_13.1

KZ-13-19_3.1

KZ-13-19_10.1

KZ-13-19_14.1

KZ-13-19_15.2

KZ-13-19_15.1

0.01

0.09

0.01

0.07

0.01

0.01

0.10

0.04

0.01

PT-2_1.2

PT-2_2.1

PT-2_3.1

PT-2_3.2

PT-2_4.1

PT-2_5.1

PT-2_5.2

PT-2_6.1

PT-2_6.2

1.09

0.21

0.14

0.11

0.32

0.50

0.08

0.11

PT2-1368.4_1.1

PT2-1368.4_2.1

PT2-1368.4_3.1

PT2-1368.4_4.1

PT2-1368.4_5.1

PT2-1368.4_6.1

PT2-1368.4_7.1

PT2-1368.4_8.1

PT 2 (1368.4)

0.08

PT-2_1.1

PT 2

0.20

KZ-13-19_6.1

Pbc, %

206

KZ-13-19_4.1

Crater

Table 6 (continued)

1790

1555

251

538

2587

1176

1370

155

1420

430

389

918

570

2253

328

352

268

479

28

59

269

425

194

31

109

157

134

U, ppm

3340

3384

171

1325

6375

1760

2086

73

657

99

554

1469

931

10,671

1360

691

289

3543

13

12

24

300

83

48

47

47

63

Th, ppm

1.93

2.25

0.71

2.55

2.55

1.55

1.57

0.49

0.48

0.24

1.47

1.65

1.69

4.89

4.28

2.03

1.11

7.64

0.48

0.21

0.09

0.73

0.44

1.60

0.45

0.31

0.48

Th/238U

232

60.4

53.6

8.5

18.4

89.3

40.3

48.8

5.2

114.0

33.9

13.2

31.0

19.3

78.1

10.9

12.1

9.2

16.5

12.8

26.0

119.0

181.0

63.7

9.5

33.0

47.2

39.9

Pb*, ppm

206

248.2

253.2

249.1

251.5

253.7

251.8

261.2

245.6

574.1

565.2

249.7

248.8

249.5

254.9

244.4

251.6

252.3

253.4

2755.0

2669.0

2659.0

2581.0

2090.0

1960.0

1935.0

1932.0

1920.0

139 282 175 292 252 244

±3.3 ±3.7 ±4.1 ±3.1 ±3.5

567

±8.8

±3.4

576

±8.4

260

306

±3.9

76

247

±3.7

±4.8

251

±3.8

±3.5

238

±3.8

2782

±45.0

291

2833

±28.0

±3.9

2644

±20.0

250

2724

±17.0

±4.0

2054

±16.0

309

1974

±28.0

277

1977

±18.0

±4.1

1959

±3.9

1921

±18.0

±42

±65

±140

±100

±32

±57

±59

±310

±18

±28

±51

±29

±36

±23

±52

±51

±51

±45

±31

±19

±14

±9

±14

±40

±28

±18

±23

207 Pb*/206Pb* Age

±17.0

Pb*/238U Age

206

0.276

0.283

0.283

0.272

0.287

0.268

0.293

0.254

0.758

0.749

0.286

0.277

0.279

0.283

0.278

0.281

0.289

0.287

14.310

14.200

12.610

12.760

6.696

5.940

5.860

5.792

5.628

Pb*/235U

207

2.3

3.1

6.3

4.6

1.9

2.8

2.9

13

1.8

2.0

2.8

2.0

2.2

1.8

2.8

2.7

2.8

2.5

2.8

1.7

1.2

1.0

1.2

2.8

1.9

1.5

1.6

±%

0.0392

0.0401

0.0394

0.0398

0.0401

0.0398

0.0414

0.0388

0.0931

0.0916

0.0395

0.0393

0.0395

0.0403

0.0386

0.0398

0.0399

0.0401

0.5330

0.5130

0.5107

0.4923

0.3830

0.3554

0.3501

0.3495

0.3470

Pb*/238U

206

0.613

0.409

0.269

0.319

0.679

0.493

0.468

0.149

0.889

0.773

0.580

0.768

0.703

0.830

0.586

0.587

0.589

0.629

0.720

0.743

0.745

0.821

0.738

0.593

0.555

0.739

0.611

КК

(continued)

1.4

1.3

1.7

1.5

1.3

1.4

1.4

2.0

1.6

1.6

1.6

1.5

1.6

1.5

1.6

1.6

1.6

1.6

2.0

1.3

0.9

0.8

0.9

1.6

1.1

1.1

1.1

±%

240 O. Petrov et al.

0.20

0.13

0.01

0.18

0.24

PT2-1368.4_11.1

PT2-1368.4_12.1

PT2-1368.4_13.1

PT2-1368.4_14.1

0.05

0.26

1.39

1.00

0.22

0.32

PT-2 (1371.2–1371.8)_7.1

PT-2 (1371.2–1371.8)_4.1

PT-2 (1371.2–1371.8)_6.1

PT-2 (1371.2–1371.8)_1.1

PT-2 (1371.2–1371.8)_5.1

PT-2 (1371.2–1371.8)_2.1

0.63

1.29

0.51

0.50

0.30

0.75

0.21

0.11

0.28

0.23

0.38

0.38

PT2-1415_10.1

PT2-1415_9.1

PT2-1415_11.1

PT2-1415_4.1

PT2-1415_2.1

PT2-1415_8.1

PT2-1415_5.1

PT2-1415_6.1

PT2-1415_1.1

PT2-1415_3.1

PT2-1415_12.1

PT2-1415_7.1

PT 2 (1415)

0.13

PT-2 (1371.2–1371.8)_3.1

PT 2 (1371.2–1371.8)

0.30

PT2-1368.4_10.1

Pbc, %

206

PT2-1368.4_9.1

Crater

Table 6 (continued)

586

356

558

718

1540

717

542

617

363

741

159

462

143

137

391

56

1395

3608

1052

1475

887

597

3089

704

2117

U, ppm

256

188

527

688

1678

699

558

741

433

309

187

489

118

49

104

31

2731

7518

1264

2611

1435

743

7168

585

3260

Th, ppm

0.45

0.55

0.97

0.99

1.13

1.01

1.07

1.24

1.23

0.43

1.21

1.09

0.86

0.37

0.28

0.58

2.02

2.15

1.24

1.83

1.67

1.29

2.40

0.86

1.59

Th/238U

232

25.9

14.5

20.0

25.7

54.1

24.8

18.7

21.0

12.1

24.3

5.2

9.8

37.2

24.4

54.7

5.0

48.9

120.0

34.6

50.8

30.0

21.2

106.0

23.1

72.5

Pb*, ppm

206

322.3

298.2

262.5

261.9

258.1

254.4

251.6

249.9

244.4

240.5

238.0

156.7

1701.0

1213.0

963.0

631.0

257.0

245.0

242.0

252.7

248.3

260.8

251.4

241.0

251.3

238 316 265 224 346 226 228 196 241 203

±3.6 ±3.8 ±3.7 ±3.8 ±3.6 ±3.5 ±3.7 ±3.9 ±4.5 ±4.7

1673

±18.0

105

1184

±14.0

39

1092

±9.1

±4.9

426

±26.0

±2.8

267

323

±3.4

±2.3

244

±3.4

254

273

±3.9

311

222

±3.6

±2.1

183

±2.3

326

±3.4

±120

±110

±81

±89

±45

±130

±170

±92

±160

±130

±360

±200

±44

±49

±67

±330

±67

±32

±51

±74

±63

±69

±44

±74

±72

207 Pb*/206Pb* Age

±3.7

Pb*/238U Age

206

0.355

0.333

0.287

0.290

0.285

0.296

0.278

0.281

0.281

0.267

0.249

0.159

4.270

2.269

1.685

0.780

0.289

0.274

0.277

0.291

0.276

0.294

0.277

0.261

0.290

Pb*/235U

207

5.5

5.1

3.8

4.1

2.4

5.8

7.7

4.3

7.1

5.7

15.0

8.4

2.7

2.8

3.5

15.0

3.1

1.7

2.4

3.5

3.1

3.4

2.4

3.5

3.5

±%

0.0513

0.0474

0.0416

0.0415

0.0409

0.0403

0.0398

0.0395

0.0386

0.0380

0.0376

0.0246

0.3019

0.2071

0.1611

0.1028

0.0407

0.0388

0.0382

0.0340

0.0393

0.0413

0.0398

0.0381

0.0398

Pb*/238U

206

0.269

0.299

0.393

0.351

0.576

0.251

0.203

0.348

0.226

0.266

0.137

0.217

0.459

0.450

0.290

0.278

0.299

0.535

0.395

0.385

0.459

0.456

0.610

0.416

0.425

КК

(continued)

1.5

1.5

1.5

1.5

1.4

1.5

1.6

1.5

1.6

1.5

2.1

1.8

1.2

1.3

1.0

4.3

0.9

0.9

1.0

1.4

1.4

1.5

1.5

1.4

1.5

±%

Isotope Chronology of Geological Processes 241

0.03

0.17

1.51

0.12

0.01

0.01

0.20

0.13

0.37

0.17

1.36

0.50

0.11

0.30

0.31

PT2 1419.3.1

PT2 1419.4.1

PT2 1419.5.1

PT2 1419.6.1

PT2 1419.7.1

PT2 1419.8.1

PT2 1419.9.1

PT2 1419.10.1

PT2 1419.11.1

PT2 1419.12.1

PT2 1419.13.1

PT2 1419.14.1

PT2 1419.15.1

PT2 1419.16.1

0.58

0.22

0.23

0.09

0.15

PT-2-1423_3.1

PT-2-1423_3.2

PT-2-1423_2.2

PT-2-1423_4.1

PT-2-1423_2.1

0.09

0.13

0.33

0.01

PT-2-1425_1.1

PT-2-1425_1.2

PT-2-1425_2.1

PT-2-1425_3.1

PT 2 (1425)

0.63

PT-2-1423_1.1

PT 2 (1423)

0.21

PT2 1419.2.1

Pbc, %

206

PT2 1419.1.1

PT 2 (1419.1)

Crater

Table 6 (continued)

1555

536

965

1341

3172

1760

1644

656

595

543

280

579

1722

346

1637

1002

283

1174

837

1550

439

1639

320

448

198

1111

U, ppm

2170

1271

1913

2988

24,899

5725

5816

7882

6765

1417

613

1530

3899

3127

8734

3545

538

4051

2471

5797

2972

1931

162

2597

178

2172

Th, ppm

1.44

2.45

2.05

2.30

8.11

3.36

3.66

12.42

11.75

2.69

2.26

2.73

2.34

9.34

5.51

3.66

1.96

3.56

3.05

3.86

7.00

1.22

0.52

5.99

0.93

2.02

Th/238U

232

53.7

18.6

32.6

46.0

62.4

22.3

20.0

59.2

113.0

19.4

9.2

19.1

56.4

11.0

52.9

32.3

9.4

38.5

26.8

51.1

14.5

54.5

51.2

14.5

53.4

38.0

Pb*, ppm

206

253.9

254.7

248.0

252.1

260.5

249.3

246.3

264.1

260.7

261.1

241.1

241.6

240.9

232.9

234.8

237.3

244.2

241.4

235.1

243.1

242.9

244.3

1085.0

238.5

1757.0

251.0

202 209 177 119

±4.4 ±4.1 ±4.3 ±4.6

205 233 187 271

±2.6 ±2.6 ±3.2 ±2.5

245

265

±4.0

282

226

±4.1

±4.3

243

±4.7

±4.3

176

±4.1

265

236

±4.1

±4.3

248

±4.3

246

191

±4.4

±4.3

274

±4.1

213

1442

±18.0

277

203

±4.3

±4.2

1771

±4.7

188

±28.0

±37

±110

±55

±45

±40

±77

±120

±50

±42

±130

±110

±77

±42

±130

±110

±57

±110

±48

±64

±45

±65

±51

±57

±89

±19

±64

207 Pb*/206Pb* Age

±4.5

Pb*/238U Age

206

0.286

0.277

0.275

0.276

0.291

0.282

0.277

0.295

0.287

0.295

0.254

0.261

0.264

0.254

0.264

0.262

0.272

0.261

0.261

0.271

0.264

0.276

2.294

0.261

4.678

0.273

Pb*/235U

207

1.9

4.7

2.6

2.2

2.4

3.8

5.5

2.7

2.4

5.9

5.1

3.8

2.5

6.0

5.0

3.0

5.3

2.7

3.3

2.7

3.3

2.8

3.5

4.3

2.1

3.3

±%

0.0402

0.0403

0.0392

0.0399

0.0412

0.0394

0.0390

0.0418

0.0413

0.0413

0.0381

0.0382

0.0381

0.0368

0.0371

0.0375

0.0386

0.0382

0.0371

0.0384

0.0384

0.0386

0.1833

0.0377

0.3133

0.0397

Pb*/238U

206

0.536

0.275

0.413

0.470

0.693

0.461

0.325

0.614

0.675

0.310

0.379

0.478

0.688

0.317

0.349

0.582

0.367

0.647

0.541

0.673

0.552

0.617

0.515

0.431

0.864

0.554

КК

(continued)

1.0

1.3

1.1

1.0

1.7

1.7

1.8

1.7

1.6

1.8

1.9

1.8

1.7

1.9

1.8

1.8

2.0

1.7

1.8

1.8

1.8

1.7

1.8

1.8

1.8

1.8

±%

242 O. Petrov et al.

0.66

0.10

0.17

0.25

0.32

PT-2-1425_6.1

PT-2-1425_7.1

PT-2-1425_8.1

PT-2-1425_9.1

101

0.01

0.08

0.16

2.06

0.73

0.37

0.29

0.36

0.10

0.66

0.16

0.53

0.01

0.02

PT-2 (1438.7–1439.3)_13.2

PT-2 (1438.7–1439.3)_13.1

PT-2 (1438.7–1439.3)_5.1

PT-2 (1438.7–1439.3)_8.1

PT-2 (1438.7–1439.3)_1.1

PT-2 (1438.7–1439.3)_4.1

PT-2 (1438.7–1439.3)_6.1

PT-2 (1438.7–1439.3)_9.1

PT-2 (1438.7–1439.3)_11.1

PT-2 (1438.7–1439.3)_14.2

PT-2 (1438.7–1439.3)_7.1

PT-2 (1438.7–1439.3)_2.1

PT-2 (1438.7–1439.3)_3.1

PT-2 (1438.7–1439.3)_14.1

0.09

0.23

0.03

1.01

1.16

KZ981_1.1

KZ981_1.2

KZ981_2.1

KZ981_3.1

KZ981_4.1

KZ 981

115

0.11

488

194

190

294

165

396

81

101

182

111

150

73

478

438

1507

2127

2435

1545

0.37

PT-2 (1438.7–1439.3)_10.1

504

925

1045

2164

1747

257

861

U, ppm

PT-2 (1438.7–1439.3)_12.1

PT 2 (1438.7–1439.3)

0.20

PT-2-1425_5.1

Pbc, %

206

PT-2-1425_4.1

Crater

Table 6 (continued)

236

101

46

113

61

282

97

59

90

147

100

59

49

73

36

192

2726

5538

5597

1584

1190

2098

3139

4111

5181

703

2326

Th, ppm

0.50

0.54

0.25

0.40

0.38

0.74

1.25

0.60

0.51

1.37

0.69

0.61

0.44

1.02

0.08

0.45

1.87

2.69

2.38

1.06

2.44

2.34

3.10

1.96

3.06

2.82

2.79

Th/238U

232

84.4

29.8

47.9

65.2

38.6

165.0

25.4

30.7

53.4

31.4

36.4

24.5

26.8

15.8

95.0

80.7

51.9

73.1

83.2

52.9

17.2

31.5

35.1

75.9

60.1

9.1

29.5

Pb*, ppm

206

1168.0

1050.0

1662.0

1476.0

1548.0

2552.0

2015.0

1939.0

1891.0

1826.0

1599.0

1593.0

1539.0

1440.0

1330.0

1227.0

253.0

253.0

252.0

252.0

250.0

250.3

246.8

257.5

252.7

257.2

251.2

1871 1922 2022 2551.6

±18.0 ±24.0 ±25.0 ±20.0

1931

1795

±18.0

±15.0

1562

±17.0

1572

1626

±19.0

±15.0

1557

±16.0

1651

1472

±18.0

±22.0

1366

±12.0

1487

1561

±13.0

1541

205

±1.9

±19.0

241

±2.1

±21.0

262

168

±2.7

±2.3

347

±2.6

291

205

±2.5

262

226

±2.5

±2.2

328

±3.2

296

±3.7

±18

±37

±17

±18

±21

±9.9

±29

±46

±25

±54

±29

±50

±49

±62

±56

±75

±49

±38

±32

±44

±110

±100

±66

±48

±43

±170

±67

207 Pb*/206Pb* Age

±2.7

Pb*/238U Age

206

3.239

2.370

4.114

3.296

3.582

11.340

6.300

5.700

5.380

4.950

3.760

3.870

3.590

3.180

2.760

2.790

0.277

0.281

0.282

0.286

0.281

0.270

0.288

0.282

0.279

0.297

0.286

Pb*/235U

207

1.7

2.5

1.8

1.7

1.9

1.1

2.2

2.9

1.8

3.2

2.0

3.0

2.9

3.5

3.1

4.2

2.2

1.9

1.7

2.1

4.9

4.4

3.1

2.3

2.1

7.7

3.1

±%

0.1986

0.1768

0.2940

0.2572

0.2715

0.4857

0.3669

0.3508

0.3408

0.3274

0.2816

0.2803

0.2696

0.2502

0.2292

0.2097

0.0401

0.0340

0.0398

0.0398

0.0396

0.0396

0.0390

0.0408

0.0400

0.0407

0.0397

Pb*/238U

206

0.821

0.613

0.843

0.833

0.800

0.846

0.666

0.481

0.621

0.362

0.605

0.454

0.417

0.385

0.333

0.287

0.336

0.467

0.549

0.419

0.263

0.247

0.346

0.433

0.480

0.191

0.350

КК

(continued)

1.4

1.5

1.5

1.4

1.5

0.9

1.4

1.4

1.1

1.2

1.2

1.4

1.2

1.4

1.0

1.2

0.8

0.9

0.9

0.9

1.3

1.1

1.1

1.0

1.0

1.5

1.1

±%

Isotope Chronology of Geological Processes 243

0.08

0.01

0.25

0.17

0.04

0.10

0.10

0.27

0.06

0.20

0.05

KZ981_7.1

KZ981_8.1

KZ981_9.1

KZ981_10.1

KZ981_11.1

KZ981_12.1

KZ981_13.1

KZ981_14.1

KZ981_15.1

KZ981_16.1

0.31

KZ-981(1126.3–1126.9)_5.1

0.07

0.38

0.37

0.07

0.60

5.72

0.47

1.90

0.31

0.29

KZ-1112-1098.4_8.1

KZ-1112-1098.4_7.2

KZ-1112-1098.4_7.1

KZ-1112-1098.4_8.2

KZ-1112-1098.4_4.1

KZ-1112-1098.4_2.1

KZ-1112-1098.4_3.1

KZ-1112-1098.4_1.1

KZ-1112-1098.4_5.1

KZ-1112-1098.4_6.1

KZ 1112 (1098.4)

0.54

0.54

KZ-981(1126.3–1126.9)_2.1

KZ-981(1126.3–1126.9)_3.1

0.34

0.36

KZ-981(1126.3–1126.9)_1.1

KZ-981(1126.3–1126.9)_4.1

KZ 981 (1126.3-1126.9)

1.32

KZ981_6.1

Pbc, %

206

KZ981_5.1

Crater

Table 6 (continued)

90

114

140

389

200

120

4156

2744

4052

4269

4186

1934

1153

1418

447

326

239

267

258

282

243

206

250

511

277

98

265

U, ppm

38

48

89

158

93

111

4545

4016

6368

7097

6226

5357

2166

3244

968

54

78

207

49

111

67

96

229

235

109

43

310

Th, ppm

0.44

0.43

0.66

0.42

0.48

0.96

1.13

1.51

1.62

1.72

1.54

2.86

1.94

2.36

2.24

0.17

0.34

0.80

0.20

0.41

0.29

0.48

0.95

0.48

0.41

0.46

1.21

Th/238U

232

25.6

26.0

32.5

73.1

36.6

5.3

162.0

105.0

152.0

156.0

148.0

68.0

38.6

47.3

14.8

88.7

52.9

84.0

37.6

47.6

42.7

60.2

64.8

120.0

20.8

16.8

16.5

Pb*, ppm

206

1842.0

1515.0

1510.0

1268.0

1174.0

319.0

286.0

280.0

275.0

269.0

258.4

257.1

245.3

244.7

243.6

1774.0

1477.0

2009.0

1006.0

1155.0

1198.0

1884.0

1700.0

1556.0

541.0

1167.0

446.5

1716 1873 1219 1227 1046 2026 1502 1828

±22.0 ±23.0 ±16.0 ±15.0 ±14.0 ±25.0 ±19.0 ±22.0

235 205 306 289 245 1263 1278 1481 1530 1811

±4.0 ±5.0 ±5.0 ±6.0 ±20.0 ±19.0 ±25.0 ±24.0 ±30.0

235

±2.9

±5.0

229 223

±2.3 ±2.6

386

1943

±19.0

158

559

±7.8

±2.8

1195

±2.3

415

±17.0

±30

±36

±85

±28

±140

±170

±30

±56

±44

±30

±54

±83

±88

±80

±95

±13

±20

±12

±32

±22

±23

±12

±18

±12

±36

±35

±110

207 Pb*/206Pb* Age

±6.8

Pb*/238U Age

206

5.050

3.470

3.370

2.500

2.280

0.357

0.326

0.321

0.302

0.299

0.287

0.284

0.271

0.263

0.289

4.879

3.326

6.290

1.727

2.198

2.279

5.362

4.373

4.486

0.710

2.188

0.545

Pb*/235U

207

2.5

2.6

4.9

2.2

7.3

7.5

2.2

3.1

2.6

2.1

2.6

3.7

3.9

3.5

4.4

1.6

1.8

1.6

2.2

1.8

1.9

1.6

1.7

1.6

2.2

2.4

5.0

±%

0.3307

0.2649

0.2640

0.2174

0.1997

0.0507

0.0454

0.0443

0.0436

0.0426

0.0409

0.0407

0.0388

0.0387

0.0385

0.3167

0.2575

0.3656

0.1689

0.1963

0.2043

0.3394

0.3017

0.2731

0.0875

0.1985

0.0717

Pb*/238U

206

0.740

0.687

0.379

0.757

0.259

0.265

0.802

0.593

0.681

0.800

0.433

0.273

0.243

0.271

0.263

0.896

0.816

0.902

0.675

0.792

0.786

0.899

0.834

0.902

0.671

0.674

0.316

КК

(continued)

1.8

1.8

1.8

1.7

1.9

2.0

1.8

1.8

1.8

1.7

1.1

1.0

1.0

1.0

1.2

1.4

1.5

1.4

1.5

1.4

1.5

1.4

1.4

1.4

1.5

1.6

1.6

±%

244 O. Petrov et al.

0.07

0.06

0.08

0.05

0.02

0.38

0.06

KZ361_2.2

KZ361_3.1

KZ361_3.2

KZ361_4.1

KZ361_5.1

KZ361_5.2

0.07

0.82

0.79

0.51

KZ-1084_1.2

KZ-1084_2.1

KZ-1084_3.1

KZ-1084_4.1

0.02

0.04

0.04

0.34

0.09

0.04

0.54

24.30

1.34

0.01

0.01

0.35

0.11

13.16

KZ774_1.1

KZ774_1.2

KZ774_2.1

KZ774_3.1

KZ774_4.1

KZ774_5.1

KZ774_6.1

KZ774_7.1

KZ774_8.1

KZ774_9.1

KZ774_10.1

KZ774_11.1

KZ774_11.2

KZ774_6.2

KZ 774

0.10

KZ-1084_1.1

KZ 1084 (1150.1)

2.13

KZ361_2.1

Pbc, %

206

KZ361_1.1

KZ 361

Crater

Table 6 (continued)

803

4267

5499

5991

4453

483

702

1495

2473

333

7001

2483

2597

2334

333

1983

439

137

141

2973

3479

288

3527

3921

222

224

789

U, ppm

1324

5511

7755

6780

12,995

553

1251

3608

3374

181

7219

1296

4574

2866

153

1708

291

93

97

761

1202

80

918

1025

52

55

320

Th, ppm

1.70

1.33

1.46

1.17

3.02

1.18

1.84

2.49

1.41

0.56

1.07

0.54

1.82

1.27

0.48

0.89

0.68

0.70

0.71

0.26

0.36

0.29

0.27

0.27

0.24

0.25

0.42

Th/238U

232

33.1

142.0

192.0

205.0

163.0

93.3

35.1

53.4

83.4

75.9

256.0

89.8

89.0

78.8

11.5

183.0

15.2

31.6

33.0

116.0

138.0

48.1

136

149.0

54.6

61.4

84.6

Pb*, ppm

206

262.2

244.5

255.8

252.3

269.1

1290.0

276.0

261.3

248.0

1515.0

267.9

265.8

252.0

248.5

253.4

652.0

252.9

1526.0

1548.0

286.7

290.4

1146.0

283.6

279.5

1621.0

1782.0

742.2

265 261 256 275 1661 277 246 1873 1883 271 246 280 253 152

±3.2 ±3.4 ±3.4 ±19.0 ±3.4 ±3.7 ±13.0 ±17.0 ±3.8 ±3.4 ±3.5 ±3.3 ±4.6

175

±5.2 ±3.2

671

273

±3.6

±10.0

267

±3.8

40

1145

±14.0

±6.3

274

±3.6

1574

273

±3.6

1558

1596

±20.0

±25.0

1748

±27.0

992

±21.0

±550

±20

±22

±15

±18

±19

±820

±48

±23

±13

±26

±19

±20

±23

±200

±36

±270

±29

±30

±18

±69

±24

±24

±18

±18

±15

±37

207 Pb*/206Pb* Age

±9.3

Pb*/238U Age

206

0.281

0.273

0.290

0.281

0.304

3.518

0.690

0.292

0.280

3.725

0.303

0.298

0.283

0.279

0.274

0.908

0.258

3.586

3.612

0.324

0.328

2.092

0.321

0.316

3.883

4.695

1.215

Pb*/235U

207

24.0

1.6

1.7

1.5

1.6

1.8

46.0

2.5

1.7

1.5

1.7

1.6

1.6

1.7

8.9

2.4

11.0

2.4

2.6

1.5

3.3

1.8

1.7

1.5

1.7

1.6

2.2

±%

0.0415

0.0387

0.0405

0.0399

0.0426

0.2215

0.0437

0.0414

0.0392

0.2649

0.0424

0.0421

0.0399

0.0393

0.0401

0.1063

0.0400

0.2672

0.2714

0.0455

0.0461

0.1946

0.0450

0.0443

0.2859

0.3184

0.1220

Pb*/238U

206

0.075

0.846

0.819

0.909

0.879

0.806

0.109

0.568

0.816

0.895

0.752

0.841

0.834

0.800

0.235

0.704

0.223

0.768

0.772

0.853

0.404

0.752

0.780

0.858

0.829

0.857

0.594

КК

(continued)

1.8

1.4

1.4

1.4

1.4

1.4

4.9

1.4

1.4

1.4

1.3

1.3

1.3

1.3

2.1

1.7

2.5

1.8

2.0

1.3

1.3

1.4

1.3

1.3

1.4

1.4

1.3

±%

Isotope Chronology of Geological Processes 245

0.12

0.21

0.13

0.04

0.03

0.01

0.13

0.07

0.01

0.30

0.15

KZ744 1023.3.1

KZ744 1023.4.1

KZ744 1023.5.1

KZ744 1023.6.1

KZ744 1023.7.1

KZ744 1023.8.1

KZ744 1023.9.1

KZ744 1023.10.1

KZ744 1023.11.1

KZ744 1023.12.1

0.10

0.03

0.20

0.57

0.19

0.07

0.01

0.16

0.10

0.01

0.13

0.29

KZ774 1029.1.1

KZ774 1029.2.1

KZ774 1029.3.1

KZ774 1029.4.1

KZ774 1029.5.1

KZ774 1029.6.1

KZ774 1029.7.1

KZ774 1029.8.1

KZ774 1029.9.1

KZ774 1029.10.1

KZ774 1029.11.1

KZ774 1029.12.1

KZ 774 (1029)

0.24

KZ744 1023.2.1

Pbc, %

206

KZ744 1023.1.1

KZ 774 [744] (1023)

Crater

Table 6 (continued)

506

2886

3748

799

1234

674

4169

724

406

2117

2831

862

760

1845

675

1249

1516

4040

2396

2034

603

1314

1200

1208

U, ppm

415

5443

16,189

696

1262

1657

15,092

750

350

2999

4164

797

554

3877

506

2042

1576

7558

2027

2995

363

1399

876

1385

Th, ppm

0.85

1.95

4.46

0.90

1.06

2.54

3.74

1.07

0.89

1.46

1.52

0.95

0.75

2.17

0.78

1.69

1.07

1.93

0.87

1.52

0.62

1.10

0.75

1.18

Th/238U

232

16.7

95.2

126.0

26.6

40.2

21.4

140.0

23.7

13.0

71.0

95.2

28.9

25.2

61.8

22.4

41.5

50.8

141.0

84.2

70.0

21.1

45.6

42.6

42.7

Pb*, ppm

206

242.8

242.7

247.4

244.5

239.8

234.8

246.7

241.1

233.9

246.5

247.4

246.8

244.1

245.8

244.9

244.4

246.3

257.5

258.4

253.0

257.0

254.6

260.8

259.1

229 316 214 206 280 206 233

±4.1 ±4.1 ±4.2 ±4.1 ±4.2 ±4.4

215

±4.3

±4.1

189

±4.2

166

365

±4.3

±4.2

216

±4.1

229

199

±4.2

±4.4

258

±4.3

220

261

±4.3

±4.2

247

±4.3

240

245

±4.7

187

218

±4.4

±4.2

227

±4.3

199

±4.5

±86

±34

±27

±52

±49

±82

±24

±72

±130

±48

±27

±51

±61

±66

±63

±44

±51

±21

±28

±31

±82

±54

±44

±77

207 Pb*/206Pb* Age

±4.4

Pb*/238U Age

206

0.269

0.266

0.280

0.268

0.263

0.270

0.273

0.260

0.259

0.272

0.275

0.268

0.268

0.267

0.288

0.269

0.269

0.289

0.290

0.282

0.287

0.281

0.289

0.283

Pb*/235U

207

4.2

2.3

2.1

2.9

2.7

4.0

2.0

3.6

5.8

2.7

2.1

2.8

3.2

3.3

3.3

2.6

2.8

1.9

2.1

2.2

4.0

2.9

2.6

3.8

±%

0.0384

0.0384

0.0391

0.0387

0.0379

0.0371

0.0390

0.0381

0.0370

0.0390

0.0391

0.0390

0.0386

0.0389

0.0387

0.0386

0.0390

0.0408

0.0409

0.0400

0.0407

0.0403

0.0413

0.0410

Pb*/238U

206

0.443

0.769

0.821

0.617

0.634

0.445

0.854

0.498

0.326

0.643

0.830

0.627

0.561

0.523

0.538

0.671

0.624

0.878

0.819

0.782

0.464

0.601

0.675

0.463

КК

(continued)

1.8

1.8

1.7

1.8

1.7

1.8

1.7

1.8

1.9

1.7

1.7

1.8

1.8

1.7

1.8

1.7

1.7

1.7

1.7

1.7

1.9

1.8

1.7

1.7

±%

246 O. Petrov et al.

0.81

0.29

KZ-774 (1032.4–1033.0)_4.1

KZ-774_1.1

0.29

0.13

0.77

0.34

0.16

0.01

OM-10-1061_4.2

OM-10-1061_3.2

OM-10-1061_2.1

OM-10-1061_1.1

OM-10-1061_4.1

OM-10-1061_3.1

0.01

0.01

0.01

0.19

0.16

0.25

0.19

0.22

0.10

0.01

0.14

4.39

OM-10-1068_3.1

OM-10-1068_12.1

OM-10-1068_8.1

OM-10-1068_6.1

OM-10-1068_4.1

OM-10-1068_2.1

OM-10-1068_9.1

OM-10-1068_11.1

OM-10-1068_10.1

OM-10-1068_1.1

OM-10-1068_7.1

OM-10-1068_5.1

OM 10 (1068)

0.16

OM-10-1061_2.2

OM 10 (1061)

0.01

0.58

KZ-774 (1032.4–1033.0)_2.1

KZ-774 (1032.4–1033.0)_3.1

0.01

1.32

KZ-774 (1032.4–1033.0)_1.1

Pbc, %

206

KZ-774 (1032.4–1033.0)_5.1

KZ 774 (1032.4–1033.0)

Crater

Table 6 (continued)

276

1571

1641

1655

1102

762

1165

564

413

455

401

362

365

266

292

345

485

368

748

189

55

112

90

2313

2624

U, ppm

272

3309

4951

3026

3580

1586

1704

907

801

952

751

589

174

68

37

24

9

6

18

136

52

33

52

3924

5096

Th, ppm

1.02

2.18

3.12

1.89

3.36

2.15

1.51

1.66

2.00

2.16

1.93

1.68

0.49

0.26

0.13

0.07

0.02

0.02

0.02

0.74

0.97

0.31

0.60

1.75

2.01

Th/238U

232

25.9

56.7

58.5

59.1

39.4

27.1

41.3

19.8

14.5

15.9

13.9

12.5

54.3

29.3

27.9

30.1

39.1

29.6

59.0

8.8

24.7

21.3

12.2

81.7

89.7

Pb*, ppm

206

639.0

264.8

262.3

262.1

262.0

261.5

260.2

257.8

257.2

257.1

255.1

254.8

1030.0

775.9

677.7

620.0

577.5

575.6

565.3

340.6

2698.0

1278.0

939.0

256.2

251.6

307 160 232 240 277 227 317 252 860

±4.5 ±4.4 ±4.3 ±4.4 ±4.4 ±4.3 ±4.3 ±4.3 ±12.0

1015

±8.2

258

820

±7.2

±4.5

640

±6.4

236

594

±5.8

255

505

±5.8

±4.5

601

±4.6

589

359

±6.3

±5.8

2664

±42.0

±6.2

1000 1148

±14.0 ±17.0

286 182

±2.2

±180

±38

±32

±38

±61

±71

±59

0.973

0.296

0.302

0.290

0.296

0.291

0.288

0.277

0.295

±74 ±67

0.288

0.283

0.285

1.745

1.172

0.933

0.831

0.741

0.772

0.753

0.402

12.980

2.360

1.568

0.278

0.285

Pb*/235U

207

±59

±64

±67

±23

±43

±75

±91

±49

±72

±46

±96

±40

±84

±96

±110

±29

207 Pb*/206Pb* Age

±2.6

Pb*/238U Age

206

9.1

2.4

2.2

2.4

3.2

3.5

3.1

3.4

3.7

3.1

3.3

3.5

1.4

2.3

3.6

4.3

2.5

3.5

2.4

4.6

3.0

4.5

5.0

5.0

1.5

±%

0.1042

0.0419

0.0415

0.0415

0.0415

0.0414

0.0412

0.0408

0.0407

0.0407

0.0404

0.0403

0.1732

0.1279

0.1109

0.1010

0.0937

0.0934

0.0917

0.0543

0.5197

0.2193

0.1569

0.0405

0.0398

Pb*/238U

206

0.223

0.709

0.769

0.711

0.538

0.487

0.549

0.524

0.483

0.572

0.540

0.530

0.614

0.433

0.272

0.225

0.423

0.298

0.479

0.411

0.620

0.326

0.327

0.203

0.577

КК

(continued)

2.0

1.7

1.7

1.7

1.7

1.7

1.7

1.8

1.8

1.8

1.8

1.8

0.9

1.0

1.0

1.0

1.0

1.0

1.2

1.9

1.9

1.5

1.6

1.0

0.9

±%

Isotope Chronology of Geological Processes 247

1.19

0.83

3.53

0.01

0.09

0.20

OM123.2.1

OM123.3.1

OM123.4.1

OM123.5.1

OM123.6.1

0.55

1.02

0.11

3.28

0.03

0.20

0.33

OM-123-1033.7_6.2

OM-123-1033.7_5.2

OM-123-1033.7_5.1

OM-123-1033.7_1.1

OM-123-1033.7_2.1

OM-123-1033.7_4.1

OM-123-1033.7_3.1

0.10

0.46

0.13

0.55

0.09

0.27

0.17

0.40

0.16

MP25kz_1.1

MP25kz_2.1

MP25kz_3.1

MP25kz_4.1

MP25kz_5.1

MP25kz_6.1

MP25kz_7.1

MP25kz_8.1

MP25kz_9.1

MP 25 KZ (37.8)

1.10

OM-123-1033.7_6.1

OM 123 (1033.7)

0.01

OM123.1.1

OM 123 (1005.6)

0.41

OM32_2.1

Pbc, %

206

OM32_1.1

OM 32 (1084.8)

Crater

Table 6 (continued)

537

673

264

489

132

559

1434

293

142

113

148

519

312

885

549

141

87

1884

1662

2139

119

4029

2442

797

374

U, ppm

336

632

14

68

32

385

1432

165

73

108

270

30

151

127

76

67

42

149

432

131

88

126

206

245

71

Th, ppm

0.65

0.97

0.05

0.14

0.25

0.71

1.03

0.58

0.53

0.99

1.88

0.06

0.50

0.15

0.14

0.49

0.50

0.08

0.27

0.06

0.76

0.03

0.09

0.32

0.20

Th/238U

232

17.9

22.2

78.8

47.8

39.4

18.3

47.2

9.8

44.2

48.0

62.1

191.0

64.3

60.3

37.3

7.9

4.8

141.0

128.0

117.0

1.8

186.0

185.0

16.8

7.5

Pb*, ppm

206

244.5

241.9

1922.0

693.0

1919.0

240.0

242.3

245.3

1987.0

2583.0

2557.0

2298.0

1339.0

491.5

485.5

406.6

400.9

538.6

554.0

398.3

105.9

334.8

545.6

154.7

148.6

2702 2740

±41.0 ±42.0

– – 1905 1709 1911 – –

±3.8 ±4.0 ±30.0 ±10.0 ±27.0 ±4.0 ±4.0

–

2363

±35.0

1916

1885

±23.0

±4.3

511

±8.6

±29.0

517

498

±9.7

±8.8

564

±10.0

316

482

±7.3

325

–

±4.1

±8.4

451

±9.4

592

±6.2

111

±9.4

28

±2.1

–

–

±25

±21

±21

–

–

–

±21

±17

±15

±10

±56

±58

±110

±140

±280

±36

±30

±24

–

±60

±20

±200

±130

207 Pb*/206Pb* Age

±2.1

Pb*/238U Age

206

0.270

0.266

5.600

1.639

5.570

0.257

0.272

0.268

5.840

12.900

12.450

8.950

3.670

0.628

0.622

0.473

0.468

0.687

0.729

0.499

0.096

0.411

0.727

0.162

0.150

Pb*/235U

207

3.4

3.8

2.1

2.0

2.1

5.8

2.3

5.0

2.0

2.2

2.1

1.9

3.7

3.2

5.3

6.6

12.0

2.5

2.3

2.2

57.0

3.3

2.0

8.7

5.8

±%

0.0387

0.0382

0.3474

0.1135

0.3467

0.0379

0.0383

0.0388

0.3610

0.4928

0.4867

0.4282

0.2308

0.0792

0.0782

0.0651

0.0642

0.0871

0.0898

0.0637

0.0166

0.0533

0.0883

0.0243

0.0233

Pb*/238U

206

0.485

0.444

0.760

0.807

0.843

0.291

0.696

0.363

0.826

0.886

0.902

0.950

0.525

0.570

0.353

0.322

0.196

0.751

0.806

0.864

0.068

0.571

0.893

0.155

0.245

КК

(continued)

1.7

1.7

1.6

1.6

1.8

1.7

1.6

1.8

1.7

2.0

1.9

1.8

1.9

1.8

1.9

2.1

2.4

1.9

1.9

1.9

3.9

1.9

1.8

1.4

1.4

±%

248 O. Petrov et al.

0.30

0.29

0.04

1.02

0.24

0.93

0.23

0.04

MP25kz_12.1

MP25kz_13.1

MP25kz_14.1

MP25kz_15.1

MP25kz_6.2

MP25kz_6.3

MP25kz_6.4

0.52

0.36

0.16

0.26

0.08

0.41

0.15

0.10

0.04

0.07

0.19

0.54

0.20

0.17

0.18

0.03

0.12

0.00

0.04

12N18_12.1

12N18_21.1

12N18_5.1

12N18_18.1

12N18_1.1

12N18_8.1

12N18_9.1

12N18_16.1

12N18_17.1

12N18_19.1

12N18_20.1

12N18_6.1

12N18_7.1

12N18_10.1

12N18_4.1

12N18_3.1

12N18_15.1

12N18_13.1

12N18_11.1

12 N 18

0.22

MP25kz_11.1

Pbc, %

206

MP25kz_10.1

Crater

Table 6 (continued)

2522

2709

2576

3545

1784

1359

1814

1954

1643

2076

1937

1309

1609

1508

1063

1212

1298

1420

811

648

269

870

260

126

96

65

670

997

U, ppm

13,173

5132

4247

8174

3876

1256

1789

2735

3281

4672

5540

2660

1286

1518

908

2279

2823

1328

1199

199

116

184

146

62

35

28

539

839

Th, ppm

5.40

1.96

1.70

2.38

2.25

0.95

1.02

1.45

2.06

2.33

2.96

2.10

0.83

1.04

0.88

1.94

2.25

0.97

1.53

0.32

0.45

0.22

0.58

0.51

0.37

0.44

0.83

0.87

Th/238U

232

92.3

98.0

92.3

127.0

63.5

48.2

64.0

69.1

57.8

72.9

67.7

45.7

56.0

52.5

36.6

41.8

44.6

47.7

27.0

88.1

73.3

29.5

8.7

4.3

28.4

20.2

22.3

32.5

Pb*, ppm

206

268.8

265.9

262.9

262.4

261.5

260.5

258.7

258.6

258.0

257.9

257.0

256.3

255.7

254.9

253.2

253.0

252.5

246.4

243.4

947.0

1775.0

247.0

246.2

248.0

1907.0

1975.0

243.8

239.5

261 277 245 264 251 240 278 282 229 275 299 280 242 241 271

±3.8 ±3.8 ±3.7 ±3.8 ±3.7 ±3.7 ±3.8 ±3.8 ±3.9 ±4.0 ±3.8 ±3.7 ±3.9 ±3.9 ±3.9

1780

±14.0

236

1922

±25.0

±3.7

–

±4.5

248

–

±4.5

±3.7

–

±5.6

253

1893

±36.0

240

1932

±30.0

±3.6

–

±3.7

–

±4.0

±26

±24

±32

±25

±43

±43

±44

0.303

0.296

0.293

0.297

0.299

0.294

0.286

0.293

0.292

±44 ±66

0.287

0.287

0.288

0.285

0.288

0.284

0.281

0.282

0.276

0.270

2.374

5.147

0.302

0.271

0.265

5.500

5.850

0.268

0.264

Pb*/235U

207

±36

±31

±44

±44

±65

±48

±69

±49

±66

±92

±18

±17

–

–

–

±23

±31

–

–

207 Pb*/206Pb* Age

±3.8

Pb*/238U Age

206

1.9

1.8

2.1

1.8

2.4

2.4

2.5

3.3

2.4

2.2

2.0

2.4

2.4

3.2

2.6

3.4

2.6

3.2

4.3

1.9

1.9

6.2

4.6

15.0

2.6

2.5

3.3

2.6

±%

0.0426

0.0421

0.0416

0.0415

0.0414

0.0412

0.0410

0.0409

0.0408

0.0408

0.0407

0.0406

0.0405

0.0403

0.0401

0.0400

0.0340

0.0390

0.0385

0.1582

0.3171

0.0391

0.0389

0.0392

0.3441

0.3584

0.0385

0.0379

Pb*/238U

206

0.787

0.819

0.734

0.796

0.617

0.635

0.623

0.458

0.611

0.684

0.741

0.622

0.612

0.468

0.596

0.449

0.577

0.464

0.363

0.860

0.869

0.300

0.412

0.151

0.863

0.715

0.507

0.606

КК

(continued)

1.5

1.5

1.5

1.4

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.5

1.6

1.6

1.6

1.9

1.9

2.3

2.2

1.8

1.7

1.6

±%

Isotope Chronology of Geological Processes 249

0.02

0.86

4.29

4.29

0.18

0.01

0.10

1.13

0.08

0.03

0.07

0.11

0.01

0.01

0.05

0.44

0.04

0.01

0.78

0.01

0.27

0.13

0.01

0.11

0.16

0.20

12N19A_1.1

12N19A_2.1

12N19A_3.1

12N19A_6.1

12N19A_7.1

12N19A_7.2

12N19A_8.1

12N19A_9.1

12N19A_10.1

12N19A_11.1

12N19A_12.1

12N19A_13.1

12N19A_14.1

12N19A_15.1

12N19A_16.1

12N19A_17.1

12N19A_18.1

12N19A_20.1

12N19A_21.1

12N19A_22.1

12N19A_23.1

12N19A_25.1

12N19A_26.1

12N19A_4.1

12N19A_24.1

12 N 19А

0.17

12N18_14.1

Pbc, %

206

12N18_2.1

Crater

Table 6 (continued)

997

205

584

1256

1422

1105

798

903

1595

759

589

1084

777

624

2887

763

2987

1205

1745

452

325

2683

1372

527

724

4600

3002

U, ppm

460

78

2451

3939

2269

1731

662

2410

2995

1275

1656

2339

2317

1942

4894

2648

6818

1788

2323

1306

806

6627

3531

690

2829

11,255

4474

Th, ppm

0.48

0.39

4.33

3.24

1.65

1.62

0.86

2.76

1.94

1.74

2.90

2.23

3.08

3.22

1.75

3.58

2.36

1.53

1.38

2.99

2.56

2.55

2.66

1.35

4.04

2.53

1.54

Th/238U

232

21.8

44.6

19.8

42.6

48.3

37.8

26.9

31.1

54.1

25.8

20.1

37.0

26.5

21.2

98.9

26.1

102.0

41.2

60.3

15.5

11.1

91.6

48.8

18.8

24.9

171.0

110.0

Pb*, ppm

206

161.5

1456.0

248.9

249.5

249.5

251.1

248.1

251.1

249.4

249.7

250.5

251.2

250.6

249.8

251.6

251.3

250.3

251.4

251.5

251.6

250.7

250.8

250.4

251.6

250.9

273.6

269.1

– – – – – – – – – – – – – – – – – – – – – – – 1421 –

±2.6 ±2.4 ±1.6 ±2.7 ±2.5 ±1.8 ±1.9 ±1.7 ±2.3 ±1.6 ±2.2 ±2.1 ±1.9 ±2.3 ±2.1 ±2.0 ±2.1 ±1.9 ±1.9 ±1.7 ±1.8 ±2.2 ±13.0 ±1.3

262

±2.0

266

±3.9

–

±28

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

±20

±35

207 Pb*/206Pb* Age

±3.8

Pb*/238U Age

206

0.165

3.139

0.267

0.273

0.265

0.272

0.256

0.250

0.272

0.264

0.241

0.284

0.288

0.274

0.277

0.274

0.277

0.268

0.265

0.284

0.282

0.276

0.293

0.297

0.258

0.308

0.303

Pb*/235U

207

4.4

1.7

2.9

1.8

1.9

3.2

2.2

4.0

1.8

2.5

5.6

2.2

2.6

2.6

1.5

2.7

1.5

2.2

4.7

3.4

3.5

1.6

14.0

9.5

5.3

1.7

2.1

±%

0.0255

0.2535

0.0395

0.0395

0.0395

0.0397

0.0392

0.0397

0.0395

0.0395

0.0396

0.0397

0.0397

0.0395

0.0398

0.0398

0.0396

0.0398

0.0398

0.0398

0.0397

0.0397

0.0396

0.0398

0.0397

0.0434

0.0426

Pb*/238U

206

0.186

0.566

0.314

0.408

0.370

0.239

0.359

0.209

0.461

0.341

0.168

0.363

0.329

0.341

0.439

0.344

0.450

0.338

0.156

0.295

0.318

0.399

0.070

0.110

0.156

0.862

0.692

КК

(continued)

0.8

1.0

0.9

0.7

0.7

0.8

0.8

0.9

0.8

0.9

1.0

0.8

0.9

0.9

0.7

0.9

0.7

0.8

0.7

10.0

1.1

0.7

1.0

1.0

0.8

1.4

1.5

±%

250 O. Petrov et al.

0.10

0.92

0.93

0.12

2.62

0.38

2.90

0.83

0.07

0.01

0.16

0.98

12N19V.7.1

12N19V.8.1

12N19V.9.1

12N19V.10.1

12N19V.11.1

12N19V.12.1

12N19V.13.1

12N19V.14.1

12N19V .15.1

12N19V.16.1

12N19V.17.1

12N19V.18.1

5.67

0.05

22.85

0.01

0.22

12N21_1.1

12N21_3.1

12N21_2.1

12N21_4.1

12N21_5.1

12 N 21

4.33

0.24

12N19V.6.1

12N19V.21.1

0.80

12N19V.5.1

0.07

0.06

12N19V.4.1

1.85

0.20

12N19V.3.1

12N19V.19.1

0.01

12N19V.20.1

0.59

12N19V.2.1

Pbc, %

206

12N19V.1.1

12 N 19V

Crater

Table 6 (continued)

1471

1273

4179

243

242

507

182

812

938

938

619

3171

2299

198

1004

2181

1575

1933

729

2039

343

786

1168

1297

3432

431

U, ppm

574

478

7669

221

8

1402

549

1581

2384

1324

992

5733

4429

657

2294

4285

3094

3817

964

3890

460

1922

1554

1353

4419

493

Th, ppm

0.40

0.39

1.90

0.94

0.03

2.86

3.12

2.01

2.63

1.46

1.66

1.87

1.99

3.42

2.36

2.03

2.03

2.04

1.37

1.97

1.39

2.53

1.37

1.08

1.33

1.18

Th/238U

232

33.1

28.4

123.0

27.2

25.4

18.5

6.3

28.4

33.2

31.8

21.3

111.0

81.6

7.0

35.3

78.3

53.6

67.8

25.0

71.5

11.4

27.0

39.1

44.6

120.0

14.8

Pb*, ppm

206

166.0

165.3

166.8

791.8

699.2

256.5

248.4

256.6

258.1

249.2

253.3

257.6

258.9

250.4

257.7

256.9

250.2

255.6

249.7

257.7

244.4

250.4

246.4

252.6

257.7

251.1

222 –57 72 195 106 147 – 137 284 360 228 –

±3.2 ±3.4 ±3.2 ±3.1 ±3.3 ±3.7 ±4.9 ±3.2 ±3.1 ±3.6 ±3.1 ±3.7

658 832 – – –

±6.9 ±5.7 ±1.6 ±1.1 ±1.1

130

192

±3.6

±4.1

11

±3.4

238

297

±3.1

–

224

±3.7

±3.4

311

±4.9

219

±3.1

–

–

–

±30

±170

±420

–

±48

–

±53

±51

±32

±77

–

±100

±130

±50

±94

±200

±44

±110

±180

±40

±84

±28

±180

207 Pb*/206Pb* Age

±4.1

Pb*/238U Age

206

0.179

0.176

0.179

1.204

0.972

0.272

0.191

0.285

0.258

0.276

0.297

0.292

0.276

0.216

0.275

0.270

0.273

0.265

0.245

0.285

0.266

0.253

0.281

0.279

0.296

0.277

Pb*/235U

207

2.1

2.0

16.0

1.6

7.9

18.0

28.0

2.5

7.6

2.6

2.7

1.9

3.5

27.0

4.5

5.6

2.5

4.2

8.2

2.3

5.0

7.5

2.2

3.9

1.7

7.9

±%

0.0261

0.0260

0.0262

0.1307

0.1146

0.0406

0.0393

0.0406

0.0409

0.0394

0.0401

0.0408

0.0410

0.0396

0.0408

0.0407

0.0396

0.0405

0.0395

0.0408

0.0386

0.0396

0.0390

0.0400

0.0408

0.0397

Pb*/238U

206

0.314

0.330

0.060

0.472

0.133

0.090

0.071

0.545

0.190

0.492

0.533

0.661

0.355

0.072

0.321

0.229

0.512

0.307

0.171

0.556

0.296

0.187

0.595

0.380

0.712

0.211

КК

(continued)

0.7

0.7

1.0

0.8

1.0

1.6

2.0

1.4

1.4

1.3

1.4

1.2

1.2

2.0

1.5

1.3

1.3

1.3

1.4

1.3

1.5

1.4

1.3

1.5

1.2

1.7

±%

Isotope Chronology of Geological Processes 251

0.02

0.05

0.05

0.04

0.07

0.01

0.21

0.07

0.42

0.01

MP2mz_3.1

MP2mz_4.1

MP2mz_5.1

MP2mz_5.2

MP2mz_6.1

MP2mz_7.1

MP2mz_8.1

MP2mz_9.1

MP2mz_10.1

0.08

0.26

0.24

0.25

0.05

0.01

0.15

0.22

0.08

0.01

0.04

0.05

0.05

12N05.1.1

12N05.2.1

12N05.3.1

12N05.4.1

12N05.5.1

12N05.6.1

12N05.7.1

12N05.8.1

12N05_1.1

12N05_2.1

12N05_3.1

12N05_4.1

12N05_5.1

12 N 05

0.06

MP2mz_2.1

Pbc, %

206

MP2mz_1.1

MP 2 206 mz

Crater

Table 6 (continued)

1737

1935

4517

2870

3057

2342

4231

3641

3190

1808

2965

2163

3450

98

190

1427

40

152

374

203

1765

1160

3582

5055

U, ppm

5487

6091

18,269

9355

10,531

7541

13,769

11,288

10,088

5218

7390

6851

11126

30

147

1895

16

51

63

62

1474

1603

6093

8696

Th, ppm

3.26

3.25

4.18

3.37

3.56

3.33

3.36

3.20

3.27

2.98

2.58

3.27

3.33

0.31

0.80

1.37

0.41

0.35

0.17

0.32

0.86

1.43

1.76

1.78

Th/238U

232

59.7

68.3

164.0

101.0

113.0

76.2

141.0

120.0

107.0

59.1

97.0

72.2

116.0

30.2

6.3

45.1

11.6

44.9

111.0

60.0

56.3

36.5

112.0

167.0

Pb*, ppm

206

252.8

259.3

266.2

257.7

272.1

239.3

245.0

241.9

245.8

240.0

240.4

245.1

246.5

1966.0

241.9

232.7

1862.0

1905.0

1916.0

1903.0

234.8

231.7

230.3

243.1

253 264 232 271 269 260 245 263

±4.3 ±4.5 ±4.6 ±3.3 ±2.9 ±2.9 ±3.0 ±2.9

1920

±37.0

273

–

±5.5

±4.6

262

±4.6

226

1938

±40.0

±4.5

1903

±35.0

235

1909

±34.0

±4.6

1900

±34.0

206

234

±4.7

291

211

±4.8

±4.6

234

±4.4

229

±4.5

±37

±35

±23

±27

±36

±72

±42

±33

±36

±87

±51

±87

±31

±23

–

±40

±43

±19

±14

±17

±34

±40

±22

±20

207 Pb*/206Pb* Age

±4.7

Pb*/238U Age

206

0.284

0.289

0.299

0.290

0.307

0.265

0.275

0.270

0.277

0.265

0.267

0.268

0.280

5.780

0.263

0.261

5.480

5.520

5.580

5.500

0.260

0.254

0.255

0.269

Pb*/235U

207

2.0

1.9

1.5

1.6

2.0

3.7

2.6

2.3

2.5

4.2

2.9

4.2

2.3

2.5

6.8

2.7

3.4

2.4

2.2

2.3

2.5

2.7

2.2

2.2

±%

0.0400

0.0411

0.0422

0.0408

0.0431

0.0378

0.0387

0.0382

0.0389

0.0379

0.0380

0.0388

0.0390

0.3565

0.0382

0.0368

0.3349

0.3439

0.3462

0.3433

0.0371

0.0366

0.0364

0.0384

Pb*/238U

206

0.581

0.605

0.750

0.695

0.621

0.536

0.718

0.786

0.769

0.452

0.663

0.455

0.797

0.865

0.343

0.760

0.716

0.896

0.936

0.910

0.810

0.773

0.900

0.918

КК

(continued)

1.2

1.2

1.1

1.1

1.2

2.0

1.9

1.8

1.9

1.9

1.9

1.9

1.8

2.2

2.3

2.0

2.5

2.1

2.0

2.1

2.0

2.1

2.0

2.0

±%

252 O. Petrov et al.

0.16

0.75

0.32

3.46

0.98

0.31

0.22

12N07_3.1

12N07_4.1

12N07_4.2

12N07_5.1

12N07_6.1

12N07_7.1

12N07_8.1

0.03

0.10

0.63

0.36

0.91

1.41

1.13

0.01

0.18

0.01

0.27

0.80

0.89

0.36

0.16

N-2_1.1

N-2_1.2

N-2_2.1

N-2_3.1

N-2_4.1

N-2_4.2

N-2_5.1

N-2_6.1

N-2_7.1

N-2_8.1

N-2_9.1

N-2_10.1

N-2_11.1

N-2_12.1

N-2_13.1

N2N2

12N08_1.1

0.79

0.12

12 N 08

1.78

12N07_2.1

Pbc, %

206

12N07_1.1

12 N 07

Crater

Table 6 (continued)

322

169

220

532

178

59

521

359

388

44

80

366

444

352

542

310

997

396

910

1814

1127

111

477

565

880

U, ppm

245

104

328

505

162

28

388

48

50

36

78

37

63

4

70

169

1153

209

700

2793

882

113

342

325

972

Th, ppm

0.78

0.64

1.54

0.98

0.94

0.49

0.77

0.14

0.13

0.84

1.02

0.10

0.15

0.01

0.13

0.56

1.19

0.54

0.80

1.59

0.81

1.05

0.74

0.59

1.14

Th/238U

232

12.5

48.9

4.4

11.0

8.2

2.2

10.7

7.9

7.9

1.4

2.6

7.5

8.5

94.1

183.0

11.6

20.7

18.0

18.2

36.6

35.1

3.5

9.7

17.8

18.6

Pb*, ppm

206

284.0

1863.0

148.2

151.7

336.6

273.6

152.1

163.7

148.8

229.7

242.5

150.8

141.9

1746.0

2136.0

272.4

153.7

331.0

147.1

144.5

229.0

228.5

150.9

231.2

154.1 – – – – – – –

±2.2 ±3.8 ±2.8 ±1.8 ±1.9 ±4.3 ±2.0

2016 1899 – – – – – – – – – – – 1904 –

±29.0 ±26.0 ±2.7 ±2.8 ±5.8 ±6.3 ±2.7 ±3.0 ±3.3 ±6.4 ±6.0 ±2.7 ±2.9 ±28.0 ±4.7

225

–

±4.1

–

±2.8

–

±26

–

–

–

–

–

–

–

–

–

–

–

±15

±10

±190

–

–

–

–

–

–

–

–

–

207 Pb*/206Pb* Age

±2.0

Pb*/238U Age

206

0.328

5.380

0.156

0.153

0.400

0.321

0.165

0.176

0.137

0.271

0.275

0.155

0.147

4.986

6.720

0.301

0.163

0.381

0.159

0.146

0.252

0.270

0.155

0.260

0.163

Pb*/235U

207

3.5

2.3

11.0

8.9

4.7

7.0

4.1

4.3

11.0

16.0

12.0

6.1

7.0

1.9

1.7

8.4

2.9

3.2

4.2

6.3

2.3

7.6

3.9

2.4

6.0

±%

0.0450

0.3351

0.0233

0.0238

0.0536

0.0434

0.0239

0.0257

0.0238

0.0363

0.0383

0.0237

0.0223

0.3111

0.3927

0.0432

0.0241

0.0527

0.0231

0.0227

0.0362

0.0361

0.0237

0.0365

0.0242

Pb*/238U

206

0.484

0.775

0.185

0.199

0.388

0.342

0.540

0.420

0.172

0.171

0.203

0.308

0.275

0.896

0.942

0.182

0.440

0.421

0.312

0.204

0.544

0.220

0.370

0.504

0.224

КК

(continued)

1.7

1.7

2.0

1.8

1.8

2.4

2.2

1.8

1.8

2.8

2.4

1.9

1.9

1.7

1.6

1.5

1.3

1.3

1.3

1.3

1.2

1.7

1.4

1.2

1.3

±%

Isotope Chronology of Geological Processes 253

0.41

0.76

0.31

0.86

1.61

0.07

2.93

0.65

1.15

N-2_16.1

N-2_17.1

N-2_18.1

N-2_19.1

N-2_20.1

N-2_21.1

N-2_22.1

N-2_23.1

2.53

0.42

0.55

N-3_2.1

N-3_1.2

N-3_1.1

0.12

0.15

0.12

0.15

0.03

0.04

1.96

0.01

0.72

1.23

0.15

0.26

OV-28-703_4.1

OV-28-703_10.1

OV-28-703_1.1

OV-28-703_11.1

OV-28-703_1.2

OV-28-703_3.1

OV-28-703_9.1

OV-28-703_2.1

OV-28-703_6.2

OV-28-703_5.2

OV-28-703_12.1

OV-28-703_5.1

OV 28 (703)

4.28

N-3_2.2

N3

0.33

N-2_15.1

Pbc, %

206

N-2_14.1

Crater

Table 6 (continued)

257

1868

575

309

2708

2194

5656

5248

1381

1582

1519

2351

666

436

86

38

252

374

91

1095

281

289

492

378

199

77

U, ppm

41

68

4

3

4398

3356

10,861

10,982

3324

1308

2015

2511

321

83

57

20

91

47

313

115

35

226

90

151

117

55

Th, ppm

0.16

0.04

0.01

0.01

1.68

1.58

1.98

2.16

2.49

0.85

1.37

1.10

0.50

0.20

0.69

0.56

0.37

0.13

3.54

0.11

0.13

0.81

0.19

0.41

0.61

0.74

Th/238U

232

25.2

147.0

44.9

22.8

104.0

84.3

211.0

194.0

49.8

55.6

53.3

81.8

28.4

16.1

2.5

1.1

5.1

7.4

1.9

351.0

5.6

11.4

10.7

7.5

9.9

25.2

Pb*, ppm

206

695.6

565.1

553.0

526.9

280.9

276.5

273.8

271.4

264.6

258.1

257.8

255.6

310.8

270.4

210.0

209.8

148.8

145.9

145.5

2041.0

145.1

286.1

161.1

145.2

361.2

2073.0

– –

±2.9 ±2.9

220 223 221 223 230 221 415 268 378 579 551 649

±3.3 ±2.2 ±2.0 ±2.2 ±2.5 ±2.4 ±2.5 ±3.6 ±6.5 ±5.2 ±4.8 ±6.6

211

–

±4.9

±4.4

2133

±27.0

346

–

±2.8

±4.1

–

±5.1

–

–

±2.8

–

–

±2.6

±5.9

–

±7.4

1802

±6.3

±60

±43

±100

±130

±37

±260

±37

±23

±53

±42

±50

±44

±120

±120

–

–

–

–

–

±13

–

–

–

–

–

±39

207 Pb*/206Pb* Age

±33.0

Pb*/238U Age

206

0.963

0.740

0.733

0.636

0.317

0.333

0.303

0.301

0.292

0.285

0.285

0.282

0.343

0.315

0.188

0.180

0.135

0.149

0.148

6.810

0.139

0.322

0.174

0.163

0.435

5.760

Pb*/235U

207

3.0

2.2

4.7

6.0

2.1

12.0

1.8

1.4

2.5

2.0

2.4

2.3

5.2

5.4

35.0

55.0

12.0

15.0

38.0

1.7

12.0

7.5

5.2

6.7

6.8

2.8

±%

0.1139

0.0916

0.0896

0.0852

0.0445

0.0438

0.0434

0.0430

0.0419

0.0409

0.0408

0.0404

0.0494

0.0428

0.0331

0.0331

0.0234

0.0229

0.0228

0.3724

0.0228

0.0454

0.0253

0.0228

0.0576

0.3794

Pb*/238U

206

0.339

0.415

0.208

0.213

0.632

0.082

0.484

0.687

0.344

0.402

0.377

0.568

0.277

0.287

0.081

0.065

0.161

0.138

0.089

0.905

0.158

0.242

0.339

0.270

0.261

0.663

КК

(continued)

1.0

0.9

1.0

1.3

1.3

0.9

0.9

1.0

0.9

0.8

0.9

1.3

1.4

1.5

2.9

3.6

2.0

2.0

3.4

1.6

1.9

1.8

1.8

1.8

1.8

1.9

±%

254 O. Petrov et al.

0.68

0.37

0.20

OV-28-703_6.1

OV-28-703_8.1

0.33

0.17

0.07

0.01

0.13

0.21

0.06

0.01

0.06

0.05

0.05

0.10

0.01

OV-28-711_10.1

OV-28-711_9.1

OV-28-711_5.1

OV-28-711_2.1

OV-28-711_4.1

OV-28-711_11.1

OV-28-711_9.2

OV-28-711_6.1

OV-28-711_7.1

OV-28-711_1.1

OV-28-711_6.2

OV-28-711_7.2

OV-28-711_3.1

1.95

19.51

0.21

0.01

0.18

4.16

0.14

0.19

OV-28-827_2.1

OV-28-827_2.2

OV-28-827_1.1

OV-28-827_11.1

OV-28-827_10.1

OV-28-827_8.1

OV-28-827_7.1

OV-28-827_4.2

OV 28 (827)

0.23

OV-28-711_8.1

OV 28 (711)

0.50

OV-28-703_7.1

Pbc, %

206

OV-28-703_13.1

Crater

Table 6 (continued)

1014

2853

1354

1498

569

1008

181

296

6023

4925

7815

7259

4952

2284

3397

4002

1907

3086

1356

1257

881

1236

341

210

264

428

U, ppm

1419

4536

3383

2545

444

1618

145

89

7126

8671

12,177

10,064

8669

5415

5569

5463

2737

2832

1155

1278

1881

1716

143

58

59

115

Th, ppm

1.45

1.64

2.58

1.76

0.81

1.66

0.83

0.31

1.22

1.82

1.61

1.43

1.81

2.45

1.69

1.41

1.48

0.95

0.88

1.05

2.21

1.43

0.43

0.29

0.23

0.28

Th/238U

232

35.8

101.0

49.7

52.5

19.8

35.1

4.6

4.9

252.0

199.0

315.0

286.0

191.0

87.1

129.0

151

70.1

113.0

49.2

44.0

30.6

42.2

46.0

26.9

30.6

43.0

Pb*, ppm

206

259.4

259.1

258.7

257.4

256.3

255.3

151.0

121.1

306.4

296.1

295.4

288.7

283.3

280.1

279.3

276.6

269.9

268.0

266.5

256.7

255.1

250.8

937.7

891.4

810.4

709.0

232 207

±4.3 ±2.4

254

±3.5

344

265

±3.4

±3.0

210

±2.7

217

224

±3.0

±2.4

247

±3.3

262

227

±2.6

248

231

±2.4

±2.6

239

±3.5

±2.3

284

±2.6

308

278

±2.7

2345

180

±2.2

±11.0

213

±2.1

±2.5

242

909

±8.0 220

850

±8.5

±2.2

756

±2.0

645

±7.6

±61

±59

±310

±58

±57

±60

0.285

0.287

0.301

0.284

0.288

0.285

0.137 0.490

±340

0.344

0.334

0.325

0.320

0.317

0.310

0.310

0.308

0.306

0.303

0.289

0.282

0.284

0.276

1.497

1.378

1.190

0.981

Pb*/235U

207

±620

±45

±31

±31

±35

±30

±32

±29

±50

±43

±31

±40

±55

±86

±92

±38

±59

±84

±82

207 Pb*/206Pb* Age

±7.4

Pb*/238U Age

206

2.8

3.1

14.0

2.7

2.7

2.7

37.0

15.0

2.3

1.8

1.6

1.9

1.8

1.7

1.5

2.5

2.1

1.7

1.9

2.5

3.9

4.1

2.0

3.0

4.1

4.0

±%

0.0411

0.0410

0.0409

0.0407

0.0406

0.0404

0.0237

0.0190

0.0487

0.0470

0.0469

0.0458

0.0449

0.0444

0.0443

0.0438

0.0428

0.0425

0.0422

0.0406

0.0404

0.0397

0.1566

0.1483

0.1340

0.1163

Pb*/238U

206

0.337

0.551

0.085

0.353

0.379

0.329

0.205

0.137

0.508

0.657

0.566

0.572

0.680

0.561

0.567

0.507

0.466

0.597

0.442

0.329

0.231

0.205

0.447

0.335

0.244

0.276

КК

(continued)

1.0

1.7

1.2

0.9

1.0

0.9

7.5

2.1

1.2

1.2

0.9

1.1

1.2

1.0

0.9

1.3

1.0

1.0

0.8

0.8

0.9

0.8

0.9

1.0

1.0

1.1

±%

Isotope Chronology of Geological Processes 255

0.10

0.17

0.20

0.18

0.27

0.28

OV-28-827_5.1

OV-28-827_9.1

OV-28-827_6.1

OV-28-827_12.1

OV-28-827_4.1

0.12

0.30

0.57

0.63

12.97

0.85

0.42

2.15

0.51

0.14

0.06

0.17

0.33

657-2b_2.1

657-2b_3.1

657-2b_4.1

657-2b_5.1

657-2b_6.1

657-2b_6.2

657-2b_7.1

657-2b_8.1

657-2b_9.1

657-2b_10.1

657-2b_11.1

657-2b_11.2

657-2b_12.1

657-2b_12.2

0.55

0.50

0.23

0.34

I-1_8.1

I-1_13.2

I-1_12.1

I-1_7.1

I1

0.70

14.28

657-2b_1.1

657 2b

0.01

OV-28-827_7.2

Pbc, %

206

OV-28-827_3.1

Crater

Table 6 (continued)

127

233

72

46

263

502

989

432

580

300

1137

435

283

309

557

602

1511

298

267

1410

2152

2350

2112

2194

4275

1135

U, ppm

53

142

22

21

18

46

33

9

62

23

255

15

37

39

73

21

53

35

22

2157

4779

5517

2633

4684

6267

1219

Th, ppm

0.43

0.63

0.32

0.47

0.07

0.09

0.03

0.02

0.11

0.08

0.23

0.04

0.14

0.13

0.13

0.04

0.04

0.12

0.08

1.58

2.29

2.43

1.29

2.21

1.51

1.11

Th/238U

232

10.9

20.1

6.4

4.1

4.5

8.7

17.1

7.3

9.6

5.5

19.7

7.4

5.9

5.2

9.7

10.2

25.6

7.1

4.8

51.3

77.9

84.4

75.7

78.4

152.0

40.3

Pb*, ppm

206

613.9

614.2

629.9

629.0

126.0

128.8

128.6

125.1

122.3

133.1

127.9

124.5

134.1

124.7

128.6

126.0

125.7

151.1

131.9

266.5

265.3

263.4

262.9

262.4

262.0

261.0

– – – –

±2.0 ±1.7 ±2.0 ±2.3

569

–

±1.8

±6.6

–

±2.5

561

–

±1.7

±5.5

–

±2.0

543

–

±4.2

526

–

±2.2

±8.5

–

±1.9

±9.8

–

±1.8

248

±3.0

–

233

±3.0

±1.6

233

±2.7

–

275

±2.7

–

218

±2.6

±3.5

262

±2.3

272

±2.3

±82

±58

±130

±140

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

±72

±61

±48

±52

±53

±30

±44

207 Pb*/206Pb* Age

±2.6

Pb*/238U Age

206

0.814

0.811

0.826

0.818

0.125

0.134

0.134

0.127

0.127

0.134

0.134

0.126

0.180

0.124

0.134

0.132

0.132

0.161

0.139

0.298

0.294

0.292

0.297

0.289

0.294

0.295

Pb*/235U

207

3.9

2.8

5.9

6.4

6.3

4.0

2.7

4.2

5.0

15

3.8

7.3

76.0

8.0

4.9

4.2

3.1

44.0

7.7

3.3

2.9

2.3

2.5

2.5

1.6

2.2

±%

0.1000

0.1000

0.1026

0.1025

0.0197

0.0202

0.0201

0.0196

0.0192

0.0209

0.0200

0.0195

0.0210

0.0195

0.0202

0.0197

0.0197

0.0237

0.0207

0.0422

0.0420

0.0417

0.0416

0.0416

0.0415

0.0413

Pb*/238U

206

0.288

0.337

0.239

0.255

0.292

0.380

0.491

0.384

0.301

0.127

0.354

0.224

0.042

0.224

0.308

0.355

0.422

0.053

0.225

0.341

0.398

0.448

0.421

0.400

0.552

0.475

КК

(continued)

1.1

1.0

1.4

1.6

1.8

1.5

1.3

1.6

1.5

1.9

1.3

1.6

3.2

1.8

1.5

1.5

1.3

2.3

1.7

1.1

1.1

1.0

1.1

1.0

0.9

1.0

±%

256 O. Petrov et al.

0.01

0.25

0.43

0.14

0.01

0.01

0.02

0.10

0.41

0.15

0.17

I-1_4.1

I-1_4.2

I-1_2.2

I-1_2.1

I-1_11.1

I-1_1.1

I-1_3.1

I-1_6.1

I-1_9.1

I-1_10.1

0.04

0.05

0.27

0.17

0.08

0.01

0.01

0.22

0.09

0.11

0.01

0.14

0.33

0.06

0.52

KYM-1_1.1

KYM-1_1.2

N-1.1.1

N-1.1.2

N-1.1.3

N-1.1.4

N-1.1.5

N-1.2.1

N-1.2.2

N-1.2.3

N-1.3.1

N-1.3.2

N-1.4.1

N-1.4.2

N-1.4.3

KYM 1

0.23

I-1_5.1

Pbc, %

206

I-1_13.1

Crater

Table 6 (continued)

264

835

257

2089

1280

3363

1892

589

396

231

556

918

849

195

302

69

171

293

89

394

67

126

164

56

174

71

115

U, ppm

1869

1232

1108

4030

2045

5956

3264

727

447

217

765

2004

927

308

185

45

101

506

146

176

30

60

80

30

130

38

40

Th, ppm

7.31

1.52

4.46

1.99

1.65

1.83

1.78

1.28

1.17

0.97

1.42

2.26

1.13

1.63

0.63

0.68

0.61

1.78

1.69

0.46

0.47

0.49

0.50

0.55

0.77

0.55

0.36

Th/238U

232

9.2

28.6

9.0

67.8

42.7

104.0

63.9

19.1

13.5

8.0

18.9

32.8

27.2

92.0

140.0

30.4

73.1

69.3

25.9

51.2

7.1

12.7

16.8

5.5

17.1

6.5

10.1

Pb*, ppm

206

254.6

251.9

255.9

238.9

245.6

228.1

248.5

238.9

250.6

256.6

250.0

262.6

235.8

2819.0

2778.0

2659.0

2597.0

1561.0

1872.0

907.1

741.6

714.2

728.0

690.0

698.7

644.6

621.8

339 227 184 191 207 269 214 138 256 23

±3.1 ±3.0 ±3.0 ±2.7 ±3.0 ±2.9 ±3.6 ±3.1 ±3.5

2652

±30.0

±3.5

2561

±19.0

239

2464

±12.0

±3.3

1843

±18.0

192

953

±8.0

±3.3

746

±9.4

112

737

±7.6

±3.0

702

±8.2

2716

680

±9.9

2697

663

±6.6

±24.0

657

±21.0

600

±8.3

±150

±60

±180

±29

±24

±13

0.258

0.282

0.272

0.263

0.277

0.250

0.271

0.259

±62 ±39

0.277

0.298

0.278

0.286

0.248

14.140

13.730

12.670

11.660

6.073

5.232

1.476

1.078

1.032

1.036

0.969

0.974

0.892

0.836

Pb*/235U

207

±29

±55

±65

±69

±90

±10

±10

±17

±12

±16

±24

±24

±63

±52

±51

±100

±58

±68

±69

207 Pb*/206Pb* Age

±6.9

Pb*/238U Age

206

6.6

2.9

7.7

1.8

1.6

1.3

2.1

3.0

1.8

2.8

3.1

3.2

4.0

1.2

1.1

1.7

1.1

1.3

1.7

1.5

3.3

2.7

2.7

5.1

2.9

3.5

3.4

±%

0.0403

0.0399

0.0405

0.0378

0.0388

0.0360

0.0393

0.0378

0.0396

0.0406

0.0396

0.0416

0.0373

0.5486

0.5387

0.5107

0.4962

0.2740

0.3369

0.1511

0.1219

0.1172

0.1195

0.1130

0.1145

0.1052

0.1013

Pb*/238U

206

0.212

0.437

0.186

0.696

0.762

0.906

0.595

0.437

0.708

0.495

0.428

0.398

0.322

0.860

0.838

0.800

0.792

0.658

0.640

0.627

0.413

0.419

0.445

0.295

0.342

0.389

0.341

КК

(continued)

1.4

1.3

1.4

1.2

1.3

1.2

1.2

1.3

1.3

1.4

1.3

1.3

1.3

1.1

1.0

1.4

0.9

0.8

1.1

0.9

1.3

1.1

1.2

1.5

1.0

1.3

1.2

±%

Isotope Chronology of Geological Processes 257

0.31

0.04

0.09

0.10

0.10

0.01

0.01

0.09

0.40

0.43

0.59

0.78

0.16

0.01

0.35

0.01

0.01

0.27

0.10

0.01

2.65

0.32

0.01

0.01

0.19

0.69

1.61

0.18

N-1.5.2

N-1.5.3

N-1.5.4

N-1.5.5

N-1.6.1

N-1.7.1

N-1.7.2

N-1.7.3

N-1.7.4

N-1.7.5

N-1.7.6

N-1.7.7

N-1.7.8

N1-1.1.11.1

N1-1.2.10.1

N1-1.3.9.1

N1-1.4.8.1

N1-1.5.7.1

N1-1.6.6.1

N1-1.8.5.1

N1-1.9.4.1

N1-1.10.3.1

N1-1.11.2.1

N1-2.(15).6.1

N1-2.(15).6.2

N1-2.(16).5.1

N1-2.(17).4.1

Pbc, %

206

N-1.5.1

Crater

Table 6 (continued)

1210

1230

926

917

4753

3518

2060

140

2935

1674

2225

2255

1083

4100

196

54

92

64

73

172

142

227

6002

505

667

918

668

382

U, ppm

3528

4354

3252

3646

7181

4113

8186

90

5148

2050

5011

7307

2214

9700

961

152

369

204

92

818

639

1173

13,790

1718

2185

3974

2630

1282

Th, ppm

3.01

3.66

3.63

4.11

1.56

1.21

4.11

0.66

1.81

1.27

2.33

3.35

2.11

2.37

5.07

2.90

4.12

3.28

1.29

4.91

4.66

5.33

2.37

3.51

3.39

4.47

4.07

3.47

Th/238U

232

37.9

36.8

29.2

28.0

143.0

111.0

68.0

42.5

93.9

54.2

73.0

72.8

35.6

127.0

6.2

1.8

3.1

2.2

2.7

5.9

4.9

7.9

194.0

16.6

23.4

30.9

23.1

13.1

Pb*, ppm

206

230.5

217.5

231.1

224.4

222.9

232.5

242.2

1911.0

235.9

238.2

241.0

238.0

242.6

227.9

236.7

243.4

243.4

244.6

265.0

250.4

256.3

255.2

238.1

242.3

258.1

247.4

254.3

251.6

89 290 215 192 220 271 330 312 251 125 194 22 282 284 133 395 305 166 265 263 1933 143 293 329 340 98 43 284

±3.2 ±3.1 ±3.2 ±3.0 ±2.9 ±3.5 ±3.7 ±3.6 ±4.3 ±4.5 ±4.5 ±4.3 ±3.1 ±8.0 ±8.6 ±8.3 ±8.5 ±8.4 ±8.2 ±62.0 ±8.5 ±8.1 ±7.8 ±6.0 ±6.7 ±5.9 ±5.9

±130

±360

±500

±120

±48

±29

±160

0.261

0.222

0.241

0.260

0.257

0.264

0.258

5.640

0.265

±35 ±77

0.267

0.259

0.272

0.289

0.242

0.268

0.276

0.247

0.266

0.281

0.280

0.294

0.295

0.268

0.267

0.281

0.272

0.289

0.262

Pb*/235U

207

±65

±59

±36

±57

±66

±51

±160

±340

±290

±160

±140

±64

±130

±11

±38

±39

±40

±87

±130

207 Pb*/206Pb* Age

±3.3

Pb*/238U Age

206

6.2

15.0

21.0

5.8

4.1

3.8

7.6

5.7

3.9

4.5

4.4

3.9

4.4

4.5

2.6

7.1

14.0

13.0

6.9

6.2

3.2

6.0

1.3

2.1

2.1

2.2

4.0

5.6

±%

0.0364

0.0343

0.0365

0.0354

0.0352

0.0367

0.0383

0.3450

0.0373

0.0376

0.0381

0.0376

0.0383

0.0360

0.0374

0.0385

0.0385

0.0387

0.0420

0.0396

0.0406

0.0404

0.0376

0.0383

0.0409

0.0391

0.0402

0.0398

Pb*/238U

206

0.418

0.182

0.137

0.466

0.858

0.942

0.473

0.652

0.918

0.785

0.819

0.914

0.818

0.787

0.511

0.254

0.131

0.150

0.239

0.235

0.460

0.237

0.932

0.605

0.611

0.587

0.322

0.244

КК

(continued)

2.6

2.7

2.9

2.7

3.6

3.6

3.6

3.7

3.6

3.6

3.6

3.6

3.6

3.6

1.3

1.8

1.9

1.9

1.6

1.5

1.5

1.4

1.2

1.3

1.3

1.3

1.3

1.4

±%

258 O. Petrov et al.

0.01

0.07

0.59

0.05

2.59

0.75

0.02

0.06

0.01

0.01

0.01

0.42

0.01

0.01

1.29

0.13

0.06

2.95

1.20

0.01

0.32

0.23

0.11

0.32

0.48

0.18

0.04

0.01

N1-2.(18).3.2

N1-2.(19).2.1

N1-2.(20).1.1

N1-2.1.9.1

N1-2.11.4.1

N1-2.12.3.1

N1-2.13.2.1

N1-2.14.1.1

N1-2.16.1

N1-2.19.1

N1-2.21.10.1

N1-2.3.8.1

N1-2.4.7.1

N1-2.6.6.1

N1-2.7.5.1

N1-2.9(18).3.1

N1-3.(1).5.1

N1-3.(1).5.2

N1-3.(2).4.1

N1-3.(2).4.2

N1-3.(4).3.1

N1-3.(5).2.1

N1-3.(5).2.2

N1-3.(6).1.1

N1-3.2.1

N1-3.2.2

N1-3.3.1.1

Pbc, %

206

N1-2.(17).4.2

Crater

Table 6 (continued)

204

4686

1784

943

1913

1817

2012

2771

3941

503

422

2001

4418

2618

2195

2185

6305

2563

1024

1448

2747

1154

2188

221

3242

1792

1380

1150

U, ppm

450

14,806

4505

2854

5677

6036

7935

7216

14,261

1877

1499

4139

10,967

6486

4174

4733

25,938

11,139

3350

2572

5941

3576

6226

401

9770

6531

4995

3864

Th, ppm

2.28

3.26

2.61

3.13

3.07

3.43

4.08

2.69

3.74

3.86

3.67

2.14

2.56

2.56

1.96

2.24

4.25

4.49

3.38

1.83

2.23

3.20

2.94

1.88

3.11

3.76

3.74

3.47

Th/238U

232

6.8

148.0

58.3

29.9

58.9

56.4

61.2

81.8

117.0

17.1

13.3

62.3

134.0

82.3

74.4

68.7

166.0

92.0

33.9

48.1

85.8

36.8

64.7

7.5

94.8

54.7

43.5

35.2

Pb*, ppm

206

250.4

232.8

240.3

232.4

226.2

228.7

223.9

217.2

219.7

247.5

226.3

229.2

223.5

228.8

250.2

231.9

193.3

264.2

243.9

245.2

230.0

234.9

216.6

243.0

215.7

223.7

232.4

225.8

231 871

±9.0

–

±6.7

±5.5

227

±6.0

243

212

±7.8

±5.8

419

±8.1

126

303

±8.8

±6.3

297

±8.1

81

338

±6.8

±5.8

252

±7.2

254

245

±5.9

±5.8

339

±8.6

201

183

±8.0

109

261

±8.3

±5.7

236

±7.6

±5.5

–

±10.0

–

277

±5.4

201

32

±6.3

±5.9

196

±6.9

369

±5.9

3±20

±25

±63

±340

±170

±62

±150

±140

0.372

0.257

0.267

0.246

0.235

0.255

0.244

0.228

0.245 0.240

–

0.172

0.253

0.245

0.275

0.286

0.264

0.223

0.296

0.272

0.285

0.249

0.263

0.240

0.171

0.243

0.227

0.253

0.265

Pb*/235U

207

±35

–

±140

±52

±130

±96

±43

±77

±36

±40

±75

±42

±58

±120

–

±70

±160

±96

±120

207 Pb*/206Pb* Age

±5.9

Pb*/238U Age

206

16.0

2.6

3.7

15.0

7.5

3.7

6.8

6.6

3.1

18.0

33.0

6.5

4.2

6.8

5.5

4.0

4.9

3.2

3.0

4.9

4.0

4.4

6.5

56.0

4.0

7.3

4.9

6.0

±%

0.0396

0.0368

0.0380

0.0367

0.0357

0.0361

0.0354

0.0343

0.0347

0.0391

0.0357

0.0362

0.0353

0.0361

0.0396

0.0366

0.0304

0.0418

0.0386

0.0388

0.0363

0.0371

0.0342

0.0385

0.0340

0.0353

0.0367

0.0357

Pb*/238U

206

0.235

0.914

0.669

0.190

0.349

0.689

0.379

0.390

0.873

0.154

0.093

0.409

0.846

0.531

0.647

0.886

0.722

0.871

0.814

0.736

0.893

0.816

0.551

0.078

0.637

0.391

0.531

0.439

КК

(continued)

3.7

2.4

2.5

2.8

2.6

2.6

2.6

2.6

2.7

2.8

3.0

2.7

3.5

3.6

3.6

3.6

3.6

2.8

2.5

3.6

3.6

3.6

3.6

4.4

2.5

2.8

2.6

2.6

±%

Isotope Chronology of Geological Processes 259

0.18

0.03

0.23

0.22

0.03

0.72

0.57

0.01

0.33

0.01

0.40

0.26

0.01

0.09

0.04

0.28

0.05

2.31

0.20

0.08

0.32

1.33

0.16

0.65

0.14

0.50

0.25

0.30

N1-3.5.2

N1-4.(12).3.1

N1-4.(13).4.1

N1-4.(13).4.2

N1-4.(15).2.1

N1-4.(17).1.1

N1-4.10.3.1

N1-4.11.2.1

N1-4.12.1

N1-4.14.1.1

N1-4.17.1

N1-4.3.8.1

N1-4.4.7.1

N1-4.6.6.1

N1-4.7.5.1

N1-4.7.5.2

N1-4.9.4.1

N1-5.(1).7.1

N1-5.(10).5.1

N1-5.(11).4.1

N1-5.(16).3.1

N1-5.(17).2.1

N1-5.(17).2.2

N1-5.(22).1.1

N1-5.(22).1.2

N1-5.(7).6.1

N1-5.12.4.1

Pbc, %

206

N1-3.5.1

Crater

Table 6 (continued)

1695

1297

1096

1553

527

1577

1279

3361

7404

2266

515

4579

2632

2127

11,423

4768

6384

2502

2846

3908

4042

2357

702

6017

3121

3296

1715

2084

U, ppm

3493

4147

2416

5016

537

3029

4010

10,655

8450

8990

413

13662

4942

5052

31,614

8576

16977

20619

16739

15633

10750

4876

1138

14354

12394

20768

5077

7682

Th, ppm

2.13

3.30

2.28

3.34

1.05

1.98

3.24

3.28

1.18

4.10

0.83

3.08

1.94

2.45

2.86

1.86

2.75

8.51

6.08

4.13

2.75

2.14

1.68

2.46

4.10

6.51

3.06

3.81

Th/238U

232

57.7

41.9

34.0

58.3

17.5

52.6

39.6

102.0

230.0

72.9

17.6

155.0

87.8

74.0

380.0

162.0

203.0

73.4

92.4

119.0

127.0

71.9

21.7

182.0

93.4

98.3

57.9

67.9

Pb*, ppm

206

249.7

237.4

227.7

275.5

242.8

245.0

225.1

222.5

229.0

236.4

246.4

249.6

245.0

255.8

244.6

249.9

233.7

215.4

239.0

223.0

231.3

223.6

226.8

222.6

220.4

219.6

248.6

239.5

230 160

±8.8

–

±8.3

±6.1

219

±7.8

88

164

±7.7

±7.0

241

±8.0

281

194

±7.6

±7.1

266

±7.8

146

218

±5.5

257

111

±6.8

±7.6

234

±5.7

±6.3

137

±7.0

–

343

±7.2

152

115

±5.7

±6.0

99

±6.0

±5.7

255

±5.5

208

248

±5.8

209

166

±5.5

±5.7

227

±6.0

231

±5.9

±120

±120

±280

±150

±290

±81

–

±150

0.268

0.263

0.237

0.313

0.259

0.274

0.213

0.238

0.259 0.251

±77

0.181

0.275

0.264

0.285

0.267

0.281

0.257

0.226

0.265

0.237

0.269

0.235

0.237

0.249

0.245

0.236

0.275

0.265

Pb*/235U

207

±33

–

±24

±57

±62

±20

±43

±33

±120

±26

±74

±52

±150

±200

±32

±100

±82

±35

±58

207 Pb*/206Pb* Age

±5.8

Pb*/238U Age

206

6.3

5.9

12.0

7.3

13.0

4.4

16.0

7.0

2.9

4.2

25.0

3.3

4.0

4.2

3.3

3.7

2.8

5.9

2.7

4.5

3.9

7.0

9.0

2.9

5.2

4.3

2.9

3.5

±%

0.0395

0.0375

0.0359

0.0437

0.0384

0.0387

0.0355

0.0351

0.0362

0.0374

0.0390

0.0395

0.0387

0.0405

0.0387

0.0395

0.0369

0.0340

0.0378

0.0352

0.0365

0.0353

0.0358

0.0351

0.0348

0.0347

0.0393

0.0379

Pb*/238U

206

0.569

0.443

0.255

0.361

0.245

0.597

0.170

0.375

0.874

0.612

0.135

0.949

0.795

0.767

0.965

0.859

0.864

0.544

0.908

0.708

0.809

0.372

0.298

0.873

0.513

0.589

0.852

0.698

КК

(continued)

3.6

2.6

3.1

2.6

3.2

2.6

2.7

2.6

2.5

2.6

3.4

3.2

3.2

3.2

3.2

3.2

2.4

3.2

2.4

3.2

3.2

2.6

2.7

2.5

2.7

2.6

2.4

2.5

±%

260 O. Petrov et al.

0.41

0.01

0.55

0.14

0.26

0.01

0.01

0.01

0.01

0.59

0.31

0.01

0.19

0.50

0.01

0.39

0.11

0.56

0.33

1.26

0.14

0.25

0.07

0.14

0.01

0.39

0.37

0.01

N1-5.15.2.1

N1-5.17.1

N1-5.19.1.1

N1-5.2.9.1

N1-5.4.8.1

N1-5.5.7.1

N1-5.6.6.1

N1-5.9.5.1

N1-6.(1).11.1

N1-6.(11).2.1

N1-6.(18).1.1 (Prism)

N1-6.(18).1.2 (Pyramid)

N1-6.(18).1.3

N1-6.(18).1.4

N1-6.(2).10.1

N1-6.(2).10.2

N1-6.(20).3.1

N1-6.(21).4.1

N1-6.(26).5.1

N1-6.(27).6.1

N1-6.(29).7.1

N1-6.(4).9.1

N1-6.(6).8.1

N1-6.10.5.1

N1-6.11.1

N1-6.11.2

N1-6.13.7.1

Pbc, %

206

N1-5.13.3.1

Crater

Table 6 (continued)

1520

644

494

801

1294

1429

607

3108

937

1136

863

527

603

1248

2373

2225

4086

2107

918

554

1573

1835

957

1794

3002

224

1712

1141

U, ppm

2289

1878

813

1988

3539

2921

2167

6311

1859

5618

1586

1264

1390

3343

6869

9573

15,399

7563

3093

1494

5877

7099

3447

3522

10,453

252

4949

3589

Th, ppm

1.56

3.01

1.70

2.56

2.83

2.11

3.69

2.10

2.05

5.11

1.90

2.48

2.38

2.77

2.99

4.44

3.89

3.71

3.48

2.79

3.86

4.00

3.72

2.03

3.60

1.16

2.99

3.25

Th/238U

232

50.9

20.3

16.9

26.5

43.5

49.8

22.0

102.0

33.8

34.8

25.4

17.6

22.2

39.4

75.1

70.7

125.0

63.5

35.3

17.9

50.7

58.3

32.5

59.1

91.4

8.0

55.2

39.5

Pb*, ppm

206

247.2

231.5

250.7

244.3

247.4

256.1

265.2

241.6

262.1

225.0

216.3

245.0

269.1

232.6

231.9

233.6

224.8

221.6

280.9

238.2

237.9

234.0

250.8

242.1

224.2

261.8

238.1

253.3

±220 –

290 202 119 331 224 360 367 607 198 248 218 280 247 272 260 303 312 – 183 429 287 323 388 221 202 332

±7.0 ±7.8 ±8.5 ±8.9 ±8.2 ±8.3 ±8.5 ±7.3 ±5.8 ±5.6 ±9.4 ±6.9 ±7.0 ±7.2 ±7.5 ±7.3 ±5.9 ±8.4 ±6.1 ±10.0 ±6.6 ±8.5 ±8.6 ±6.3 ±5.7 ±8.7

±64

±110

±94

±65

±80

±180

±110

±81

±190

±160

±170

±40

±92

±80

±34

±180

±95

±62

±52

±37

±83

±67

±56

±160

±61

354

±110

68

±8.3

207 Pb*/206Pb* Age

±9.1

Pb*/238U Age

206

0.286

0.253

0.276

0.290

0.285

0.291

0.321

0.262

0.242

0.258

0.247

0.275

0.304

0.259

0.262

0.257

0.250

0.241

0.369

0.280

0.279

0.258

0.290

0.255

0.245

0.298

0.278

0.262

Pb*/235U

207

4.5

5.5

4.8

4.6

5.0

8.3

6.4

4.3

17.0

9.9

8.9

7.5

8.1

3.5

5.1

5.4

2.9

8.1

5.1

4.6

4.2

3.9

5.1

4.6

4.3

7.3

4.5

5.8

±%

0.0391

0.0366

0.0396

0.0386

0.0391

0.0405

0.0420

0.0382

0.0415

0.0355

0.0341

0.0387

0.0426

0.0367

0.0366

0.0369

0.0355

0.0350

0.0445

0.0376

0.0376

0.0370

0.0397

0.0383

0.0354

0.0415

0.0376

0.0401

Pb*/238U

206

0.787

0.455

0.533

0.779

0.705

0.317

0.603

0.592

0.197

0.270

0.384

0.413

0.337

0.871

0.602

0.763

0.868

0.327

0.516

0.795

0.841

0.911

0.704

0.782

0.829

0.371

0.797

0.633

КК

(continued)

3.6

2.5

2.6

3.6

3.5

2.6

3.8

2.6

3.3

2.7

3.4

3.1

2.7

3.0

3.0

4.1

2.5

2.6

2.7

3.6

3.6

3.6

3.6

3.6

3.6

2.7

3.6

3.6

±%

Isotope Chronology of Geological Processes 261

0.58

0.09

0.01

0.54

0.01

0.67

0.08

0.31

0.01

0.18

0.79

0.01

0.19

0.13

0.10

0.01

0.15

0.10

0.72

0.18

1.19

0.90

0.40

0.01

0.01

0.86

0.10

0.51

N1-6.16.4.1

N1-6.23.3.1

N1-6.26.1

N1-6.32.2.1

N1-6.33.1.1

N1-6.6.1

N1-6.7.9.1

N1-6.9.8.1

N1-7.(1).8.1

N1-7.(13).7.1

N1-7.(13).7.2

N1-7.(14).6.1

N1-7.(14).6.2

N1-7.(18).5.1

N1-7.(19).1.1 (4.3)

N1-7.(19).4.1

N1-7.(19).4.2

N1-7.(21).3.1

N1-7.(21).3.2

N1-7.(21).3.3

N1-7.(22).2.1

N1-7.(23).1.1

N1-7.11.7.1

N1-7.12.6.1

N1-7.15.5.1

N1-7.16.4.1

N1-7.16.4.2

Pbc, %

206

N1-6.14.6.1

Crater

Table 6 (continued)

604

1048

607

8220

541

692

1673

542

1822

297

1622

993

1228

1524

918

4046

740

825

1530

1641

992

694

1244

1414

1457

1283

5821

1276

U, ppm

1286

3429

1024

26,516

1343

1029

3287

763

3033

290

1927

1108

1640

5367

1186

9192

1506

1425

2077

3284

2231

829

4130

2689

2196

3495

10,899

4657

Th, ppm

2.20

3.38

1.74

3.33

2.57

1.54

2.03

1.45

1.72

1.01

1.23

1.15

1.38

3.64

1.34

2.35

2.10

1.78

1.40

2.07

2.32

1.23

3.43

1.97

1.56

2.81

1.93

3.77

Th/238U

232

20.7

32.4

20.0

239.0

17.9

24.4

55.4

17.9

57.6

9.8

56.8

34.6

40.4

53.1

28.8

121.0

24.3

27.2

50.4

55.0

33.2

23.2

40.2

46.4

46.4

42.8

175.0

40.0

Pb*, ppm

206

251.0

227.7

240.4

214.7

244.6

257.8

241.9

240.6

232.4

241.8

257.2

256.0

244.1

256.0

231.2

220.9

241.5

240.5

242.2

246.9

245.9

246.1

236.5

242.2

233.2

245.8

221.7

230.0

129 202 334 245 301 – 236 100 298 223 – 298 174 249 241 550 204 200 68 200 – – 208 403 242 90 202 192

±7.7 ±8.7 ±5.6 ±8.5 ±8.4 ±6.0 ±8.8 ±8.7 ±7.3 ±7.3 ±7.4 ±6.6 ±7.0 ±7.7 ±6.4 ±11.0 ±7.7 ±7.6 ±7.0 ±7.8 ±7.3 ±7.9 ±7.8 ±6.7 ±7.8 ±7.3 ±8.2

±310

±190

±270

±25

±120

±140

–

0.273

0.249

0.250

0.238

0.292

0.283

0.233

0.220

0.254

±49 –

0.250

0.281

0.280

0.311

0.285

0.258

0.238

0.275

0.241

0.267

0.281

0.257

0.273

0.235

0.276

0.259

0.285

0.242

0.243

Pb*/235U

207

±170

±85

±68

±170

±52

±84

±49

±46

–

±62

±36

±160

±56

–

±71

±76

±140

±40

±140

207 Pb*/206Pb* Age

±8.1

Pb*/238U Age

206

14.0

8.9

12.0

3.3

6.2

6.9

7.6

18.0

3.7

7.9

4.8

5.3

8.4

3.8

4.8

3.7

3.7

7.6

4.1

3.9

7.5

3.5

8.5

4.7

4.1

7.2

3.9

7.1

±%

0.0397

0.0360

0.0380

0.0339

0.0387

0.0408

0.0382

0.0380

0.0367

0.0382

0.0407

0.0405

0.0386

0.0405

0.0365

0.0349

0.0382

0.0380

0.0383

0.0390

0.0389

0.0389

0.0374

0.0383

0.0368

0.0389

0.0350

0.0363

Pb*/238U

206

0.240

0.363

0.274

0.946

0.524

0.449

0.405

0.185

0.824

0.408

0.642

0.831

0.318

0.808

0.646

0.825

0.842

0.406

0.753

0.914

0.484

0.712

0.424

0.756

0.598

0.501

0.899

0.505

КК

(continued)

3.3

3.2

3.3

3.2

3.2

3.1

3.1

3.3

3.0

3.2

3.1

4.4

2.7

3.1

3.1

3.0

3.1

3.1

3.1

3.6

3.6

2.5

3.6

3.6

2.5

3.6

3.6

3.6

±%

262 O. Petrov et al.

0.01

2.06

0.01

0.01

0.01

0.07

0.14

0.01

0.41

0.12

0.01

0.32

0.01

0.01

0.07

0.41

0.21

1.18

0.26

0.24

0.07

0.25

0.22

0.01

0.40

0.33

0.52

0.01

N1-7.17.3.2

N1-7.18.1

N1-7.19.1

N1-7.20.2.1

N1-7.22.1

N1-7.24.1.1

N1-7.3.14.1

N1-7.4.13.1

N1-7.4.13.2

N1-7.5.12.1

N1-7.6.11.1

N1-7.7.10.1

N1-7.9.8.1

N1-8.(1).12.1

N1-8.(10).5.1

N1-8.(16).4.1

N1-8.(17).3.1

N1-8.(18).2.1

N1-8.(19).1.1

N1-8.(19).1.2

N1-8.(2).11.1

N1-8.(3).10.1

N1-8.(5).9.1

N1-8.(6).8.1

N1-8.(7).7.1

N1-8.(7).7.2

N1-8.(7).7.3

Pbc, %

206

N1-7.17.3.1

Crater

Table 6 (continued)

739

609

677

598

2946

510

422

504

1671

1209

194

512

1530

3369

536

1577

2317

530

2774

894

625

2016

1534

2575

718

598

147

184

U, ppm

1011

877

687

1145

7106

567

653

505

4062

2381

289

1102

4649

5978

1279

2862

3003

849

6944

2073

1396

4806

3656

3953

825

3016

394

403

Th, ppm

1.41

1.49

1.05

1.98

2.49

1.15

1.60

1.03

2.51

2.04

1.54

2.23

3.14

1.83

2.47

1.88

1.34

1.65

2.59

2.40

2.31

2.46

2.46

1.59

1.19

5.21

2.76

2.27

Th/238U

232

22.8

19.1

21.9

21.1

86.4

17.3

14.4

16.6

53.0

39.7

5.9

17.9

46.2

98.3

18.1

52.0

73.3

18.2

88.0

28.0

20.4

59.3

50.8

80.8

24.4

19.5

5.2

6.8

Pb*, ppm

206

227.0

229.6

237.3

258.7

216.4

249.4

251.1

242.1

233.0

241.3

222.9

256.3

221.6

215.1

249.1

242.9

232.3

252.9

233.5

229.7

241.7

216.8

243.6

231.4

250.0

240.8

253.0

274.0

126 333

±6.9

–

±8.7

±7.0

171

±7.8

220

176

±6.7

±7.2

269

±6.4

146

332

±7.9

±7.9

258

±7.6

229

178

±7.3

±6.5

367

±8.0

205

204

±7.5

±7.6

217

±7.3

160

362

±7.9

277

235

±6.8

±7.7

230

±5.8

±7.4

281

±7.2

196

234

±6.1

134

282

±5.9

±7.3

–

±7.3

842

±10.0

±56

±140

±110

±220

±28

±86

±180

±81

0.262

0.243

0.261

0.276

0.239

0.273

0.270

0.273

0.263 0.247

±110

0.218

0.277

0.239

0.242

0.288

0.272

0.251

0.297

0.255

0.252

0.283

0.240

0.270

0.262

0.277

0.273

0.204

0.402

Pb*/235U

207

±110

–

±140

±86

±35

±49

±37

±75

±80

±58

±140

±120

±50

±42

±25

±45

±62

–

±64

207 Pb*/206Pb* Age

±9.1

Pb*/238U Age

206

4.0

6.7

5.7

9.8

3.3

4.9

8.4

4.7

5.5

5.5

40.0

6.9

4.8

3.4

3.9

3.6

4.5

4.8

4.1

7.0

6.1

3.9

3.0

3.4

3.2

3.7

46.0

4.6

±%

0.0358

0.0363

0.0375

0.0409

0.0341

0.0394

0.0397

0.0383

0.0368

0.0381

0.0352

0.0406

0.0350

0.0339

0.0394

0.0384

0.0367

0.0400

0.0369

0.0363

0.0382

0.0342

0.0385

0.0366

0.0396

0.0381

0.0401

0.0434

Pb*/238U

206

0.781

0.464

0.537

0.319

0.929

0.643

0.375

0.661

0.577

0.557

0.099

0.451

0.637

0.894

0.832

0.891

0.701

0.676

0.795

0.461

0.547

0.830

0.805

0.946

0.783

0.680

0.087

0.738

КК

(continued)

3.1

3.1

3.1

3.1

3.0

3.1

3.1

3.1

3.2

3.1

4.0

3.1

3.1

3.0

3.2

3.2

3.2

3.2

3.3

3.2

3.3

3.2

2.4

3.2

2.5

2.5

4.0

3.4

±%

Isotope Chronology of Geological Processes 263

0.09

0.01

0.04

0.01

0.99

0.59

0.01

0.09

0.22

0.61

0.19

0.08

0.79

1.48

1.55

0.17

0.02

0.92

0.94

0.14

0.59

0.01

1.24

0.50

0.26

0.24

0.16

0.02

N1-8.10.1

N1-8.10.2

N1-8.11.1.1

N1-8.11.1.2

N1-8.17.1

N1-8.9.2.1

N1-9.(1).9.1

N1-9.(17).6.1

N1-9.(17).6.2

N1-9.(17).6.3

N1-9.(18).5.1

N1-9.(20).4.1

N1-9.(22).3.1

N1-9.(23).2.1

N1-9.(25).1.1

N1-9.(5).8.1

N1-9.(7).7.1

N1-9.12.6.1

N1-9.14.5.1

N1-9.15.4.1

N1-9.16.3.1

N1-9.17.1

N1-9.17.2

N1-9.21.2.1

N1-9.24.1.1

N1-9.25.1

N1-9.4.9.1

Pbc, %

206

N1-8.(8).6.1

Crater

Table 6 (continued)

1571

2406

1634

3878

1029

366

921

1475

2644

1078

414

7440

2669

1964

794

1084

602

1634

703

1714

1930

592

66

350

1442

1277

809

1643

U, ppm

4287

4368

3886

5997

1564

406

1575

4703

3337

2097

637

9661

3825

3280

1364

2165

1116

3233

938

2448

2065

1132

79

412

4553

3169

1775

2262

Th, ppm

2.82

1.88

2.46

1.60

1.57

1.15

1.77

3.29

1.30

2.01

1.59

1.34

1.48

1.73

1.78

2.06

1.91

2.04

1.38

1.48

1.11

1.97

1.25

1.22

3.26

2.56

2.27

1.42

Th/238U

232

54.2

75.4

56.2

121.0

34.9

11.7

31.5

46.2

83.7

36.7

12.8

219.0

82.8

58.0

24.8

34.1

18.3

50.9

23.2

53.1

60.9

19.8

2.5

11.7

47.9

42.1

28.4

51.6

Pb*, ppm

206

253.8

230.7

252.6

229.2

248.4

232.7

252.8

229.5

232.9

248.4

226.3

217.2

228.3

214.4

226.8

229.8

223.7

229.2

241.1

228.0

232.3

246.5

273.6

244.5

246.4

242.4

258.2

231.2

231 307

±7.9

–

±7.0

±5.5

202

±6.5

203

275

±6.8

±8.0

136

±6.5

136

–

±7.0

±7.1

–

±7.0

231

259

±7.0

±6.0

193

±6.9

206

83

±7.4

±6.1

220

±6.8

412

218

±6.9

–

468

±8.8

±8.2

316

±8.7

±7.3

85

±9.2

–

452

±8.7

198

230

±5.8

±7.3

242

±8.4

272

±6.4

±64

±40

±150

±62

±87

±220

±130

–

0.291

0.255

0.276

0.243

0.275

0.255

0.303

0.225

0.243 0.254

–

0.223

0.237

0.257

0.227

0.195

0.223

0.250

0.249

0.250

0.251

0.256

0.303

0.315

0.254

0.301

0.268

0.287

0.260

Pb*/235U

207

±56

–

±27

±40

±140

–

–

±83

±90

±200

±69

±38

±70

±260

±420

±110

±42

±50

±59

207 Pb*/206Pb* Age

±6.9

Pb*/238U Age

206

4.2

3.0

7.2

4.1

4.5

10.0

6.8

7.2

4.0

21.0

11.0

3.2

3.5

6.6

13.0

10.0

4.8

4.9

8.9

4.3

3.5

4.8

12.0

18.0

6.2

3.1

3.3

4.0

±%

0.0402

0.0364

0.0400

0.0362

0.0393

0.0368

0.0400

0.0362

0.0368

0.0393

0.0357

0.0343

0.0360

0.0338

0.0358

0.0363

0.0353

0.0362

0.0381

0.0360

0.0367

0.0390

0.0434

0.0387

0.0390

0.0383

0.0409

0.0365

Pb*/238U

206

0.752

0.818

0.445

0.771

0.549

0.264

0.489

0.447

0.799

0.166

0.276

0.933

0.870

0.467

0.245

0.305

0.657

0.619

0.347

0.715

0.881

0.756

0.270

0.210

0.580

0.802

0.757

0.763

КК

(continued)

3.2

2.4

3.2

3.2

2.5

2.7

3.3

3.2

3.2

3.4

3.2

3.0

3.1

3.1

3.1

3.1

3.2

3.1

3.1

3.0

3.0

3.6

3.3

3.8

3.6

2.5

2.5

3.1

±%

264 O. Petrov et al.

0.07

0.01

0.12

0.01

0.06

1.46

0.63

0.01

0.01

0.12

0.09

0.05

0.20

0.10

0.05

1.99

0.12

0.04

0.01

0.25

0.01

0.12

0.30

0.27

N1-9.8.7.1

N1-10.2.6.1

N1-10.3.5.1

N1-10.4.4.1

N1-10.5.3.1

N1-10.6.2.1

N1-10.7.1.1

N-11.1.1

N-11.1.2

N-11.1.3

N-11 3.1

N-11 3.2

N-11 4.1

N-11 4.2

N-11 6.1

N-11 6.2

N-11 7.1

N1-1.12.1.1

N-12 1

N-12 3

N-12 4

N-12 5

N-12 6

0.08

0.02

T1-6.1

T1 9.1

Т-1/Т-22 (n = 220) Talnakh intrusive

1.34

N1-9.6.8.1

Pbc, %

206

N1-9.5.1

Crater

Table 6 (continued)

6365

6228

471

462

2477

677

478

994

1691

1154

372

4643

3515

3952

3587

3763

7344

3637

6819

2163

2922

8404

940

2736

1119

7775

5974

U, ppm

8077

9366

1666

1666

9481

2238

852

1669

3115

1667

419

7026

4573

10,149

5866

9252

17,886

5608

6983

1694

4001

6655

2250

2566

2074

11,684

7557

Th, ppm

1.31

1.55

3.65

3.73

3.96

3.42

1.84

1.73

1.90

1.49

1.16

1.56

1.34

2.65

1.69

2.54

2.52

1.59

1.06

0.81

1.41

0.82

2.47

0.97

1.92

1.55

1.31

Th/238U

232

191.0

225.0

14.7

14.7

84.3

22.1

16.6

31.2

52.3

37.5

12.6

157.0

97.4

128.0

129.0

148.0

271.0

120.0

200.0

73.2

101.0

250.0

29.8

98.7

37.4

241.0

180.0

Pb*, ppm

206

221.0

265.0

229.0

233.5

250.1

241.0

254.7

232.0

227.8

239.1

243.9

248.5

204.5

238.8

263.5

289.0

271.0

244.0

216.8

247.7

250.3

219.5

233.8

264.9

247.7

228.7

219.8

546 213 9 146 285 274 251 210 277 338 358 311 1081 269 290 320 305 253 244 419 149

±8.3 ±7.6 ±8.8 ±8.7 ±7.6 ±6.8 ±7.6 ±8.1 ±1.1 ±1.0 ±0.9 ±1.0 ±2.6 ±1.5 ±2.7 ±8.3 ±3.6 ±1.5 ±1.1 ±1.9 ±2.8

240

262

±9.3

251

481

±7.8

±5.8

200

±5.4

222

±7.1

±19

±31

±84

±110

±40

±45

0.245

0.297

0.245

0.281

0.279

0.269

0.292

0.267

±82 ±70

0.258

0.269

0.401

0.285

0.239

0.277

0.298

0.318

0.303

0.275

0.245

0.264

0.252

0.241

0.298

0.298

0.306

0.250

0.242

Pb*/235U

207

±32

±45

±150

±24

±30

±44

±29

±23

±22

±22

±20

±100

±270

±24

±56

±54

±33

±30

±63

207 Pb*/206Pb* Age

±5.2

Pb*/238U Age

206

2.8

2.5

3.8

5.0

1.8

2.1

3.4

5.1

1.8

2.1

7.7

1.1

1.4

2.0

1.4

3.0

3.0

3.0

3.6

5.7

12.0

3.7

4.4

4.3

3.5

3.4

3.7

±%

0.0349

0.0420

0.0362

0.0369

0.0396

0.0381

0.0403

0.0366

0.0360

0.0378

0.0386

0.0393

0.0322

0.0377

0.0417

0.0458

0.0429

0.0385

0.0342

0.0392

0.0396

0.0346

0.0369

0.0420

0.0392

0.0361

0.0347

Pb*/238U

206

0.955

0.842

0.326

0.168

0.258

0.309

0.427

0.707

0.655

0.300

0.141

0.355

0.316

0.215

0.301

0.945

0.948

0.948

0.971

0.627

0.307

0.961

0.813

0.834

0.906

0.925

0.663

КК

(continued)

2.7

2.1

1.2

0.8

0.5

0.6

1.5

3.6

1.2

0.6

1.1

0.4

0.4

0.4

0.4

2.9

2.9

2.9

3.5

3.6

3.6

3.5

3.6

3.6

3.2

3.2

2.4

±%

Isotope Chronology of Geological Processes 265

0.04

0.09

0.19

0.03

T1 37.1

T1 37.2

T1 38.1

Т2-11.1

0.07

1.18

0.01

Т2-21.1

Т2-4.1

Т2-8.1

0.29

0.44

Т2-2.1

Т2-2.2

0.10

3.05

T1 36.1

0.58

0.06

T1 35.1

Т2-11.2

0.08

Т2-12.1

0.03

T1 33.1

0.16

Т1 27.1

T1 30.2

0.92

T1 26.2

0.22

0.01

T1 26.1

0.02

0.17

Т1 24.2

T1 25.1

Т1 29.1

489

0.67

Т1 24.1

Т1 30.1

829

0.02

1.06

T1 23.1

1774

3516

1964

6328

1868

628

1655

3778

8600

2187

4797

3029

1509

3867

3834

1516

4674

6090

1471

1411

2626

6634

6122

10,290

0.13

0.01

Т1 17.1

2442

1577

U, ppm

Т1 19.1

0.52

0.06

Т1_15.1

Pbc, %

206

Т1_15.2

Crater

Table 6 (continued)

5165

2231

26,377

6302

1077

1713

5966

16,624

6325

5480

2884

2088

7095

4091

1154

14,895

8521

1041

3730

1896

7346

811

1808

8273

17,425

4008

4919

3218

Th, ppm

1.52

1.17

4.31

3.49

1.77

1.07

1.63

2.00

2.99

1.18

0.98

1.43

1.90

1.10

0.79

3.29

1.45

0.73

2.73

0.75

1.14

1.71

2.25

1.40

1.75

2.33

2.08

2.11

Th/238U

232

125.0

66.0

215.0

49.6

20.6

57.1

134.0

301.0

69.9

139.0

94.6

48.1

115.0

115.0

52.9

167.0

214.0

44.0

45.0

87.5

170.0

18.0

24.0

162.0

285.0

71.0

75.9

44.4

Pb*, ppm

206

261.0

246.0

250.0

195.0

240.0

253.0

261.0

258.0

235.0

214.0

230.0

228.0

219.0

221.0

257.0

262.0

258.0

221.0

233.0

245.0

189.0

268.0

212.0

196.0

205.0

294.0

229.0

207.0

228 295

±6.4 ±6.1

228 320 252 237 254

±5.7 ±6.0 ±6.0 ±5.6 ±6.2 ±7.3

±7.3

±7.0

±7.0

±4.9

±1.8

±5.4

244

278

255

470

338

112

237

249

235

±5.8

±7.2

367

±5.4

163 322

±5.4

±5.3

213

285

±5.0

±6.3

185

±7.7

214 –

±5.2 ±6.1

283

246

266

164

±20

±87

±22

±90

±84

±160

±28

±28

±42

0.291

0.278

0.280

0.239

0.279

0.266

0.290

0.288

0.263

0.236

0.257

±23 ±26

0.262

0.241

0.244

0.302

0.302

0.278

0.242

0.265

0.271

0.213

0.291

0.208

0.214

0.231

0.329

0.257

0.222

Pb*/235U

207

±100

±27

±31

±45

±38

±51

±43

±83

±22

±42

±140

–

±35

±14

±41

±36

±77

207 Pb*/206Pb* Age

±5.8

±8.3

±5.6

±5.2

Pb*/238U Age

206

3.0

4.8

3.0

4.8

3.8

6.9

3.1

3.1

3.2

2.9

2.9

5.2

2.9

3.0

2.9

2.7

3.0

3.4

4.5

2.8

3.3

6.6

7.6

3.1

2.9

3.4

2.9

4.2

±%

0.0414

0.0389

0.0396

0.0308

0.0380

0.0399

0.0413

0.0408

0.0372

0.0337

0.0363

0.0360

0.0345

0.0348

0.0406

0.0415

0.0409

0.0348

0.0368

0.0388

0.0297

0.0424

0.0334

0.0308

0.0323

0.0467

0.0362

0.0326

Pb*/238U

206

0.956

0.605

0.948

0.533

0.203

0.313

0.919

0.921

0.823

0.923

0.934

0.517

0.916

0.895

0.734

0.784

0.691

0.843

0.593

0.940

0.824

0.446

0.389

0.871

0.979

0.849

0.846

0.608

КК

(continued)

2.9

2.9

2.9

2.6

0.8

2.2

2.9

2.9

2.7

2.7

2.7

2.7

2.7

2.7

2.1

2.1

2.1

2.9

2.7

2.7

2.7

2.9

2.9

2.7

2.9

2.9

2.5

2.5

±%

266 O. Petrov et al.

0.07

0.06

0.18

0.18

1.22

0.12

0.24

0.44

0.10

2.77

0.74

0.14

0.07

0.01

T2 32.1

T2 32.2

T2 36.1

T2 36.2

T2 43.1

T2-12.2

T2-38.1

T2-38.2

T2-41.1

T2-41.2

T2-42.1

T3 12,1

T3 12.2

Т3-10.1

0.13

0.19

0.01

Т3-26.1

Т3-27.1

Т3-27.2

2.29

0.18

Т3-22.1

Т3-22.2

0.02

0.44

Т3-13.1

Т3-20.1

0.49

0.06

T2 27.1

0.37

0.33

T2 17.2

Т3-10.2

0.15

T2 17.1

Т3-11.1

0.06

3.04

Т2-8.2

Pbc, %

206

Т2-9.1

Crater

Table 6 (continued)

5008

3680

2043

2651

1854

2052

4941

3281

1518

2906

3584

3331

1396

2467

2535

1758

1975

2483

1945

1770

863

3614

2131

4951

4476

8142

1778

2683

U, ppm

10,689

6810

2431

4925

2842

3674

10,580

5846

1502

4717

6033

5150

1297

3561

5301

1673

3380

3891

2280

5695

875

11,551

3370

10,472

12,556

23,014

2014

9038

Th, ppm

2.21

1.91

1.23

1.92

1.58

1.85

2.21

1.84

1.02

1.68

1.74

1.60

0.96

1.49

2.16

0.98

1.77

1.62

1.21

3.33

1.05

3.30

1.63

2.19

2.90

2.92

1.17

3.48

Th/238U

232

190.0

143.0

76.6

93.9

68.6

76.5

192.0

125.0

56.1

106.0

110.0

97.8

47.3

91.1

89.9

62.2

70.8

86.4

63.1

52.5

28.4

100.0

68.5

151.0

134.0

259.0

67.0

92.0

Pb*, ppm

206

278.0

285.0

275.0

260.0

266.0

273.0

285.0

278.0

270.0

269.0

226.0

216.0

248.0

264.0

260.0

259.0

263.0

256.0

236.0

219.0

242.0

205.0

237.0

225.0

220.0

235.0

267.0

251.0

224 220 248 228 229 202 319 321 200 174 234 96 250 236 228

±5.8 ±5.9 ±6.2 ±5.4 ±6.4 ±5.7 ±6.2 ±5.3 ±5.6 ±5.4 ±5.4 ±5.6 ±5.3 ±5.7 ±5.9 ±6.8

±6.8

±7.0

±6.8

±6.4

±6.7

±6.8

±6.9

±6.8

278

238

219

215

354

317

285

196

220

301

279

±6.2

±6.7

279

236

±22

±47

±47

±52

±150

±93

±22

±68

±94

±32

±31

±29

±120

±280

±51

±95

±97

±51

±110

±46

±80

±32

±36

±18

±31

±42

±250

±25

207 Pb*/206Pb* Age

±7.8

±7.0

Pb*/238U Age

206

0.315

0.318

0.304

0.286

0.311

0.314

0.324

0.304

0.298

0.307

0.249

0.240

0.276

0.276

0.289

0.280

0.287

0.295

0.271

0.239

0.267

0.226

0.264

0.248

0.242

0.265

0.302

0.279

Pb*/235U

207

2.7

3.2

3.2

3.4

7.2

4.8

2.7

3.8

4.8

2.9

3.0

2.9

5.8

12.0

3.1

4.6

4.7

3.1

5.4

3.3

4.4

3.0

3.1

2.8

3.0

3.2

11.0

3.1

±%

0.0441

0.0453

0.0436

0.0411

0.0421

0.0432

0.0451

0.0441

0.0428

0.0426

0.0356

0.0341

0.0391

0.0418

0.0412

0.0410

0.0416

0.0405

0.0373

0.0345

0.0382

0.0323

0.0374

0.0355

0.0347

0.0370

0.0423

0.0397

Pb*/238U

206

0.934

0.775

0.780

0.747

0.360

0.527

0.933

0.652

0.535

0.877

0.894

0.906

0.377

0.178

0.693

0.466

0.459

0.689

0.498

0.800

0.618

0.890

0.865

0.958

0.897

0.822

0.263

0.934

КК

(continued)

2.5

2.5

2.5

2.5

2.6

2.5

2.5

2.5

2.6

2.5

2.7

2.7

2.2

2.2

2.1

2.1

2.2

2.1

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

3.0

2.9

±%

Isotope Chronology of Geological Processes 267

1.47

0.27

0.01

T3-38.1

T3-40.1

Т3-3.1

0.20

0.28

0.35

0.01

0.43

0.21

0.01

0.09

T5-10.2

T5-11.1

T5-4.1

T5-8.1

T5-9.1

Т6-11.1

Т6-11.2

Т6-12.1

2540

0.23

0.02

Т3-8.2

T5-10.1

982

0.24

0.11

Т3-7.1

Т3-8.1

3520

2898

4372

2483

1993

3958

5637

5226

1456

18,348

2857

1826

0.15

0.13

Т3-6.1

552

1453

3868

3477

606

537

159

2804

316

4020

817

1717

1935

2199

U, ppm

Т3-6.2

0.27

0.77

Т3-5.1

Т3-5.2

0.01

0.19

T3-36.2

0.07

1.65

T3-36.1

Т3-3.2

0.07

T3-33.2

Т3-4.1

0.77

0.29

Т3-28.3

Т3-33.1

0.13

0.17

Т3-28.1

Pbc, %

206

Т3-28.2

Crater

Table 6 (continued)

8124

4234

2462

4014

6463

9717

8258

2243

34,670

3041

1381

4035

2568

4348

394

1691

5753

1570

444

328

58

4354

209

5473

734

5378

4569

5516

Th, ppm

2.90

1.00

1.02

2.08

1.69

1.78

1.63

1.59

1.95

1.24

1.45

1.46

1.45

1.28

0.74

1.20

1.54

0.47

0.76

0.63

0.38

1.60

0.68

1.41

0.93

3.24

2.44

2.59

Th/238U

232

100.0

158.0

85.0

70.2

143.0

204.0

192.0

48.9

635.0

88.0

32.4

101.0

68.3

125.0

19.3

51.1

139.0

122.0

20.6

18.0

5.0

90.0

10.0

139.0

27.0

64.6

71.2

84.8

Pb*, ppm

206

254.0

265.0

251.0

258.0

265.0

266.0

269.0

247.0

255.0

254.0

242.0

260.0

275.0

262.0

255.0

258.0

264.0

258.0

251.0

247.0

230.0

236.0

236.0

254.0

246.0

274.0

270.0

283.0

– 170 – 364

±6.4 ±4.7 ±6.2 ±5.3 ±7.2 254

266 232 250 298 271 262

±5.2 ±5.2 ±5.5 ±5.5 ±5.4 ±5.4 ±3.5 ±3.4

234

248

213

193

±7.1

±3.4

285

201

224

198

213

252

283

±6.9

±6.4

±6.8

±6.5

±6.9

±6.4

±6.5

206

222

±5.0

±7.2

312

391

273

226

±40

±22

±53

±74

±28

±44

±55

±65

±16

±50

±43

±58

±51

±35

±230

±71

±27

±19

±49

±120

–

±46

–

±32

±110

±150

±49

±44

207 Pb*/206Pb* Age

±5.0

±6.9

±6.7

±7.0

Pb*/238U Age

206

0.282

0.297

0.276

0.290

0.299

0.303

0.301

0.273

0.286

0.277

0.275

0.285

0.304

0.286

0.280

0.288

0.300

0.289

0.275

0.290

0.230

0.250

0.230

0.280

0.280

0.326

0.305

0.313

Pb*/235U

207

2.2

1.7

2.7

3.9

2.4

2.8

3.2

3.5

2.2

3.6

3.5

3.6

3.4

2.9

10.0

4.0

2.8

3.0

3.6

5.9

27.0

2.8

18.0

2.4

5.2

7.0

3.3

3.2

±%

0.0402

0.0420

0.0397

0.0408

0.0420

0.0421

0.0427

0.0390

0.0403

0.0402

0.0383

0.0412

0.0435

0.0414

0.0404

0.0408

0.0418

0.0408

0.0397

0.0390

0.0360

0.0370

0.0370

0.0400

0.0390

0.0435

0.0428

0.0448

Pb*/238U

206

0.622

0.815

0.514

0.552

0.867

0.736

0.657

0.609

0.948

0.797

0.840

0.706

0.752

0.857

0.262

0.634

0.904

0.960

0.811

0.367

0.101

0.716

0.150

0.819

0.401

0.368

0.766

0.797

КК

(continued)

1.4

1.4

1.4

2.1

2.1

2.1

2.1

2.2

2.1

2.9

2.9

2.5

2.5

2.5

2.7

2.5

2.5

2.9

2.9

2.2

2.7

2.0

2.7

2.0

2.1

2.6

2.5

2.5

±%

268 O. Petrov et al.

3000

2556

0.01

0.25

0.04

0.15

0.11

0.07

0.20

0.15

T8 14.1

T8 14.2

T8 16.1

T8 17.1

T8-29.1

Т8_15.1

Т8_2.1

Т8_34.1

4447

1652

1750

2169

1320

1553

745

3071

0.01

0.18

Т8-6.2

6390

5071

2472

3436

2994

2501

4267

11,144

13,600

5365

5784

8278

4711

3788

702

10,300

7839

2617

U, ppm

Т8-9.1

0.05

0.01

Т8-37.1

Т8-6.1

0.03

0.08

Т8-32.1

Т8-33.1

0.10

0.09

Т8-26.1

Т8-31.1

0.01

0.16

Т8-21.2

Т8-24.1

0.04

0.01

Т8-20.1

Т8-21.1

0.02

0.03

Т6-9.1

Т8-1.1

0.04

0.06

Т6-6.1

Т6-8.1

0.01

0.64

Т6-5.1

Т6-5.2

0.01

0.01

Т6-14.1

Pbc, %

206

Т6-2.1

Crater

Table 6 (continued)

4213

4216

5488

1838

5089

1614

2215

764

4197

6947

11691

7902

3282

5301

4500

4682

5275

25,377

29,346

8638

9092

13,919

11,564

4371

855

8954

9236

4193

Th, ppm

2.63

1.70

1.89

1.09

2.42

1.26

1.47

1.06

1.41

1.61

1.89

1.61

1.37

1.59

1.55

1.93

1.28

2.35

2.23

1.66

1.62

1.74

2.54

1.19

1.26

0.90

1.22

1.66

Th/238U

232

50.0

80.8

94.8

62.0

64.7

43.0

47.6

24.5

106.0

152.0

226.0

174.0

86.8

119.0

101.0

88.7

153.0

407.0

504.0

186.0

204.0

291.0

160.0

135.0

22.9

379.0

287.0

90.6

Pb*, ppm

206

223.0

233.0

233.0

260.0

220.0

240.0

226.0

242.0

254.0

252.0

261.0

253.0

258.0

255.0

247.0

261.0

263.0

269.0

272.0

255.0

260.0

258.0

250.0

263.0

239.0

271.0

269.0

255.0

275

272

±3.6

±5.5

262

176

215

±5.8

±5.6

255

±6.3

221

191

±6.0

±5.6

283

±6.4

272 213

±3.4

±3.3

270

±3.4 ±3.4

226

253

228

239

225

238

252

255

255

242

236

259

158

263

254

227

±64

±49

±38

±42

±35

±32

±59

±41

±54

±26

±19

±28

±36

±27

±39

±37

±49

±15

±13

±22

±24

±17

±32

±28

±180

±15

±17

±31

207 Pb*/206Pb* Age

±3.5

±3.4

±3.3

±7.3

±3.5

±3.5

±3.5

±3.4

±3.4

±3.4

±3.3

±3.5

±3.7

±3.5

±3.5

±3.4

Pb*/238U Age

206

0.249

0.251

0.256

0.294

0.241

0.268

0.245

0.274

0.279

0.285

0.294

0.286

0.285

0.285

0.273

0.290

0.290

0.299

0.305

0.286

0.291

0.287

0.277

0.295

0.257

0.304

0.301

0.282

Pb*/235U

207

3.8

3.2

3.0

2.3

3.1

3.0

3.7

3.2

2.7

1.8

1.6

1.8

2.1

1.8

2.2

3.3

2.5

1.5

1.4

1.7

1.7

1.5

1.9

1.8

8.1

1.5

1.5

1.9

±%

0.0351

0.0367

0.0368

0.0412

0.0347

0.0379

0.0356

0.0383

0.0402

0.0399

0.0412

0.0400

0.0408

0.0404

0.0391

0.0413

0.0416

0.0425

0.0432

0.0404

0.0411

0.0409

0.0395

0.0416

0.0378

0.0429

0.0426

0.0403

Pb*/238U

206

0.667

0.761

0.831

0.604

0.869

0.886

0.730

0.835

0.504

0.764

0.853

0.746

0.670

0.756

0.632

0.872

0.545

0.895

0.922

0.813

0.786

0.869

0.697

0.749

0.196

0.897

0.872

0.718

КК

(continued)

2.5

2.5

2.5

1.4

2.7

2.7

2.7

2.7

1.4

1.4

1.3

1.4

1.4

1.4

1.4

2.9

1.4

1.3

1.3

1.3

1.3

1.3

1.3

1.4

1.6

1.3

1.3

1.4

±%

Isotope Chronology of Geological Processes 269

1184

1338

1298

650

1200

0.01

0.43

0.01

0.09

0.10

0.01

1.47

Т10_29.1

Т10_3.1

Т10_3.2

Т10_31.1

Т10-7.1

T10 2.1

T10 2.2

889

518

1381

357

706

0.09

0.01

Т10_24.1

1204

1123

1160

814

581

Т10_24.2

0.16

0.56

0.17

Т10-5.2

Т10-6.1

0.29

0.68

Т10-5.1

Т10-6.2

1.23

Т10-4.1

Т10_19.1

1203

3.44

Т10-27.1

1370

1404

0.51

0.23

Т10-26.1

2260

1124

471

1092

2647

2363

399

1192

1928

2564

U, ppm

Т10-26.2

0.64

0.58

Т10-21.1

Т10-25.1

0.06

1.39

Т10-20.1

Т10-20.2

0.48

0.39

Т10-16.2

Т10-18.1

0.01

0.97

Т10-12.1

Т10-16.1

0.17

0.11

Т8_34.2

Pbc, %

206

Т10-11.1

Crater

Table 6 (continued)

1300

2387

4962

1336

3341

3802

463

1542

2379

3659

2720

2596

1816

3739

1317

1391

2543

2065

3509

2123

398

1215

6073

8804

554

2505

3289

2591

Th, ppm

2.59

1.79

4.27

2.12

2.66

2.94

1.34

2.26

2.77

3.14

2.37

2.23

1.67

3.33

1.67

2.47

1.87

1.56

1.60

1.95

0.87

1.15

2.37

3.85

1.43

2.17

1.76

1.04

Th/238U

232

17.5

47.6

40.2

20.3

44.3

39.1

11.1

22.7

28.9

37.0

40.5

41.4

39.0

41.2

27.7

20.0

49.0

48.8

80.4

40.2

16.8

38.9

93.7

82.3

13.9

36.5

67.6

80.9

Pb*, ppm

206

246.0

253.0

246.0

230.0

251.0

215.0

231.0

237.0

239.0

226.0

251.0

253.0

254.0

259.0

248.0

245.0

256.0

261.0

260.0

261.0

258.0

262.0

259.0

255.0

253.0

226.0

258.0

232.0

370

±5.9

190

263 258 80

±8.6 ±6.6 ±6.9

420 277

±6.2 ±5.7

163

633

332 ±5.5

±6.1

±6.0

126

±5.3 ±5.6

159 177

±5.5

62

265

–

339

108

181

414

141

319

240

172

278

285

226

159

±230

±27

±49

±66

±51

±90

±150

±51

±52

±94

±62

±84

±130

±170

±230

–

±59

±140

±150

±210

±310

±74

±72

±96

±240

±42

±80

±52

207 Pb*/206Pb* Age

±5.4

±5.7

±5.6

±6.1

±5.4

±5.6

±5.6

±5.7

±6.4

±5.6

±5.4

±5.3

±6.1

±1.3

±5.4

±5.6

Pb*/238U Age

206

0.255

0.284

0.276

0.259

0.302

0.231

0.306

0.274

0.260

0.239

0.296

0.274

0.273

0.267

0.278

0.240

0.297

0.274

0.282

0.314

0.275

0.302

0.288

0.276

0.286

0.256

0.285

0.249

Pb*/235U

207

10.0

2.9

4.1

3.8

3.4

4.7

7.5

3.4

3.3

4.7

3.5

4.2

5.9

7.4

10.0

21.0

3.4

6.2

6.6

9.6

13.0

3.9

3.8

4.6

11.0

1.9

4.0

3.3

±%

0.0388

0.0401

0.0389

0.0363

0.0398

0.0339

0.0364

0.0374

0.0378

0.0357

0.0397

0.0400

0.0402

0.0410

0.0391

0.0387

0.0405

0.0412

0.0412

0.0414

0.0409

0.0415

0.0410

0.0404

0.0401

0.0357

0.0408

0.0367

Pb*/238U

206

0.286

0.913

0.858

0.663

0.739

0.555

0.358

0.749

0.748

0.528

0.616

0.516

0.374

0.305

0.226

0.123

0.638

0.351

0.328

0.232

0.191

0.553

0.559

0.458

0.223

0.307

0.526

0.745

КК

(continued)

2.9

2.7

3.5

2.5

2.5

2.6

2.7

2.6

2.5

2.5

2.2

2.2

2.2

2.2

2.3

2.5

2.2

2.2

2.2

2.2

2.5

2.2

2.1

2.1

2.4

0.6

2.1

2.5

±%

270 O. Petrov et al.

1565

3215

0.14

0.11

0.15

Т12_19.2

Т12_24.1

Т12_25.1

0.04

0.10

Т12_12.2

Т12_19.1

0.01

0.34

Т12_11.1

Т12_12.1

0.14

0.01

Т12-23.1

Т12-4.1

0.01

0.15

Т12-2.1

Т12-2.2

0.16

0.55

Т12-13.1

Т12-17.1

0.01

0.13

Т12-1.2

Т12-10.1

985

0.01

0.32

Т12-9.2

Т12-1.1

1200

2036

1152

1313

2627

1226

1526

5418

3844

1523

2471

1603

1952

4276

5328

1989

15,208

0.01

0.45

Т12-8.1

1082

4594

Т12-9.1

0.09

0.90

Т12-7.1

Т12-8(2).1

2102

0.66

0.01

Т12-4.5

Т12-5.1

1583

4704

1.55

2007

0.06

0.27

Т12-4.2

785

222

Т12-4.3

0.04

U, ppm

Т12-4.4

1.95

T12 6.2

Pbc, %

206

T12 6.1

Crater

Table 6 (continued)

2980

4026

1945

3554

3797

3169

3603

20744

8253

4774

6234

8592

4252

8694

11,771

3454

14732

2827

28,250

3841

2532

5020

14,775

17,426

4880

4753

1784

326

Th, ppm

2.57

2.04

1.74

2.80

1.49

2.67

2.44

3.96

2.22

3.24

2.61

5.54

2.25

2.10

3.78

3.62

2.86

1.47

1.92

3.67

1.67

2.47

3.32

3.83

3.18

2.45

2.35

1.52

Th/238U

232

36.9

67.0

35.7

44.6

89.8

41.6

47.0

197.0

135.0

53.2

85.8

55.6

68.8

151.0

109.0

33.8

189.0

74.4

565.0

37.9

54.7

73.6

159.0

167.0

56.3

66.5

26.8

8.2

Pb*, ppm

206

227.0

242.0

228.0

250.0

252.0

249.0

227.0

267.0

259.0

257.0

256.0

254.0

259.0

259.0

249.0

252.0

261.0

274.0

273.0

256.0

257.0

258.0

253.0

260.0

257.0

243.0

251.0

265.0

±4.2 267

269

±3.5 263

230

±3.5

±5.6

±5.9

±5.6

±6.1

±6.5

±6.1

±5.6

±3.5

±3.4

±3.6

±3.4

±3.5

224

183

184

262

222

156

336

248

279

258

270

211

238

268

±3.4 ±3.4

278

289

142

±3.7

±3.4

±4.8

138

±3.5 ±3.7

286

273

230

±3.5

±3.4

±3.5

195

235

±3.5

7

±6.6

±69

±53

±57

±51

±32

±80

±60

±22

±42

±65

±30

0.250

0.263

0.247

0.280

0.277

0.267

0.263

0.298

0.293

0.288

0.288

0.288 0.279

±56

0.291

0.276

0.285

0.297

0.292

0.307

0.272

0.289

0.292

0.285

0.288

0.290

0.265

0.279

0.267

Pb*/235U

207

±92

±53

±27

±97

±31

±79

±12

±150

±45

±32

±64

±26

±200

±110

±39

±300

207 Pb*/206Pb* Age

±7.6

Pb*/238U Age

206

3.9

3.4

3.5

3.3

3.0

4.2

3.6

1.6

2.3

3.2

1.9

4.2

2.8

2.7

1.8

4.5

1.9

3.8

1.4

6.5

2.4

2.0

3.1

1.8

8.8

5.0

3.2

13.0

±%

0.0358

0.0383

0.0360

0.0395

0.0398

0.0394

0.0359

0.0422

0.0409

0.0406

0.0404

0.0402

0.0410

0.0409

0.0394

0.0398

0.0414

0.0434

0.0433

0.0405

0.0407

0.0408

0.0400

0.0412

0.0407

0.0385

0.0397

0.0420

Pb*/238U

206

0.643

0.737

0.714

0.746

0.883

0.591

0.690

0.819

0.599

0.445

0.722

0.337

0.498

0.504

0.759

0.335

0.700

0.470

0.933

0.228

0.585

0.697

0.443

0.763

0.190

0.299

0.848

0.226

КК

(continued)

2.5

2.5

2.5

2.5

2.6

2.5

2.5

1.3

1.4

1.4

1.4

1.4

1.4

1.3

1.4

1.5

1.3

1.8

1.3

1.5

1.4

1.4

1.4

1.4

1.7

1.5

2.7

2.9

±%

Isotope Chronology of Geological Processes 271

2.61

0.60

4.85

4.06

Т16-6.2

Т17-4.1

Т17-1.1

Т17-1.2

0.01

0.26

Т16-3.1

Т16-6.1

0.05

0.01

Т15-4.1

Т16-1.1

0.38

0.02

Т14-1.2

Т15-1.1

2.16

1.04

Т13-5.1

Т13-5.2

0.16

0.43

Т13-10.1

Т13-10.2

0.22

0.68

Т13-6.3

Т13-7.1

0.04

0.63

Т13-6.1

Т13-6.2

0.03

0.01

Т13-3.1

Т13-4.1

0.19

0.16

Т13-2.1

Т13-2.2

0.26

0.12

Т13-12.1

Т13-16.1

0.05

0.13

Т13-11.1

Т13-11.2

0.09

0.02

Т13-1.1

Pbc, %

206

Т13-1.2

Crater

Table 6 (continued)

119

75

3733

1667

1391

8588

1071

3565

2453

1501

682

619

683

1252

266

2725

2915

7439

2529

5668

968

1179

2593

1644

1738

2528

12,888

2914

U, ppm

187

89

6472

4163

2667

19,953

1813

14,086

10,347

345

1673

1757

1487

5462

315

4854

7089

16,000

5725

17,041

2189

3104

7002

3611

2566

4276

37,065

3613

Th, ppm

1.63

1.22

1.79

2.58

1.98

2.40

1.75

4.08

4.36

0.24

2.53

2.93

2.25

4.51

1.22

1.84

2.51

2.22

2.34

3.11

2.34

2.72

2.79

2.27

1.53

1.75

2.97

1.28

Th/238U

232

4.2

2.6

136.0

60.7

49.3

320.0

37.6

127.0

87.2

31.3

24.0

23.5

24.8

42.3

8.7

97.1

104.0

276.0

90.8

204.0

34.5

43.1

92.0

58.7

60.7

89.8

488.0

102.0

Pb*, ppm

206

251.0

238.0

265.0

261.0

260.0

274.0

258.0

262.0

261.0

154.0

256.0

272.0

266.0

248.0

240.0

261.0

261.0

272.0

264.0

264.0

262.0

268.0

261.0

262.0

257.0

261.0

278.0

258.0

719

±4.0

±9.7

±11.0

±1.2

±2.0

±1.7

±0.9

±2.0

±1.1

±1.2

–

–

294

407

269

238

271

262

272

152

39

±7.2 ±6.8

326

254

267

222

282

262

300

265

193

269

283

254

219

266

283

267

–

–

±63

±190

±82

±21

±47

±32

±31

±110

±190

±180

±120

±62

±160

±44

±110

±21

±57

±23

±77

±61

±35

±57

±44

±35

±14

±36

207 Pb*/206Pb* Age

±7.0

±6.2

±7.1

±1.2

±5.4

±1.0

±1.3

±1.0

±1.8

±1.7

±1.2

±1.5

±1.4

±1.2

±1.0

±1.3

Pb*/238U Age

206

0.230

0.210

0.302

0.312

0.293

0.305

0.291

0.294

0.295

0.164

0.262

0.377

0.307

0.277

0.269

0.289

0.296

0.306

0.302

0.297

0.285

0.302

0.296

0.294

0.284

0.295

0.316

0.290

Pb*/235U

207

50.0

62.0

2.8

8.4

3.6

1.0

2.2

1.4

1.4

5.3

8.5

8.7

6.1

3.7

7.5

1.9

5.4

1.0

2.6

1.1

3.4

2.8

1.6

2.5

2.0

1.6

0.7

1.6

±%

0.0397

0.0376

0.0420

0.0413

0.0412

0.0434

0.0409

0.0414

0.0414

0.0242

0.0406

0.0431

0.0421

0.0392

0.0379

0.0414

0.0414

0.0431

0.0419

0.0418

0.0414

0.0425

0.0413

0.0414

0.0406

0.0413

0.0441

0.0408

Pb*/238U

206

0.078

0.074

0.164

0.094

0.179

0.368

0.357

0.305

0.342

0.494

0.317

0.309

0.441

0.687

0.401

0.248

0.391

0.362

0.195

0.356

0.210

0.237

0.299

0.228

0.283

0.300

0.512

0.326

КК

(continued)

3.9

4.6

0.5

0.8

0.7

0.4

0.8

0.4

0.5

2.6

2.7

2.7

2.7

2.5

3.0

0.5

2.1

0.4

0.5

0.4

0.7

0.7

0.5

0.6

0.6

0.5

0.4

0.5

±%

272 O. Petrov et al.

6457

0.19

0.87

0.01

T22-1 1

T22-2 1

T22-4 1

8.82

1.22

0.04

0.09

0.03

0.06

84410,11Z42.1

84410,11Z42.2

8441Z1.1

8441Z10.1

8441Z10.2

8441Z12.1

844 (n = 45) Kharaelakh intrusive

0.01

0.33

Т18-5.1

Т18-6.1

0.13

0.07

Т18-3.3

Т18-4.1

0.05

0.02

Т18-3.1

Т18-3.2

0.10

0.02

Т18-22.2

Т18-8

0.36

0.03

Т18-11.2

Т18-22.1

0.11

0.18

0.27

0.18

Т18-7.2

Т18-7.3

Т18-9.1

0.01

Т18-11.1

4707

12.03

Т17-2.3

Т18-7.1

804

1570

1552

393

1244

359

507

1285

868

687

6362

4270

3947

3153

4684

9653

1800

1848

4946

2292

837

2272

4783

931

1607

0.01

0.34

U, ppm

Т17-2.1

Pbc, %

206

Т17-2.2

Crater

Table 6 (continued)

4651

3519

411

3810

935

1665

2498

2471

1588

16,283

8858

5869

4410

15,931

49,226

1415

1433

8098

3350

751

8295

5807

1582

6857

4172

3013

1156

Th, ppm

3.06

2.34

1.08

3.16

2.69

3.39

2.01

2.94

2.39

2.64

2.14

1.54

1.45

3.51

5.27

0.81

0.80

1.69

1.51

0.93

1.33

1.27

0.72

1.48

4.63

1.94

1.49

Th/238U

232

52.4

56.0

18.2

41.4

11.7

20.0

43.0

29.0

22.0

252.0

166.0

142.0

124.0

179.0

358.0

51.2

59.6

151.0

73.7

29.0

226.0

179.0

79.2

184.0

42.0

57.8

28.4

Pb*, ppm

206

246.0

265.0

338.0

245.0

237.0

264.0

245.0

241.0

237.0

290.0

285.0

265.0

289.0

281.0

272.0

210.0

237.0

225.0

236.0

255.0

257.0

279.0

256.0

282.0

291.0

263.0

260.0

277

±1.1 211

1390 200 296 413 222 260

±7.7 ±11.0 ±8.3 ±7.7

293

±5.0

±7.7

–

±5.0

±9.5

250

±4.9

337 301

±7.0 ±7.1

338

305

269

270

332

265

281

±6.5

±7.2

±6.9

±6.6

±1.0

±1.1

±0.8

251

±1.0 ±1.6

286

243

251

1487

260

431

±30

±25

±66

±26

±180

±520

±49

–

±90

±54

±22

±32

±57

±24

±25

±29

±38

±17

±58

±77

±24

±41

±72

±21

±470

±62

±78

207 Pb*/206Pb* Age

±1.3

±1.3

±1.3

±8.7

±6.5

±6.6

Pb*/238U Age

206

0.300

0.300

0.400

0.300

0.300

0.500

0.280

0.240

0.260

0.332

0.332

0.308

0.331

0.317

0.307

0.242

0.267

0.254

0.259

0.285

0.291

0.317

0.285

0.316

0.590

0.296

0.315

Pb*/235U

207

3.5

3.4

4.4

3.4

8.2

27.0

3.0

7.8

4.5

3.4

2.7

2.9

3.6

2.7

2.7

1.4

1.7

0.8

2.6

3.4

1.1

1.9

3.2

1.0

25.0

3.7

4.4

±%

0.0390

0.0420

0.0540

0.0390

0.0380

0.0420

0.0390

0.0380

0.0370

0.0460

0.0452

0.0420

0.0458

0.0446

0.0431

0.0331

0.0375

0.0355

0.0373

0.0403

0.0408

0.0442

0.0405

0.0447

0.0461

0.0417

0.0412

Pb*/238U

206

0.924

0.949

0.747

0.940

0.400

0.135

0.698

0.273

0.474

0.729

0.929

0.869

0.712

0.925

0.919

0.364

0.270

0.415

0.185

0.193

0.345

0.254

0.167

0.442

0.122

0.683

0.591

КК

(continued)

3.2

3.2

3.3

3.2

3.3

3.7

2.1

2.1

2.1

2.5

2.5

2.5

2.5

2.5

2.5

0.5

0.5

0.4

0.5

0.7

0.4

0.5

0.5

0.5

3.1

2.5

2.6

±%

Isotope Chronology of Geological Processes 273

0.01

0.11

0.33

0.01

0.12

0.11

0.04

0.19

0.10

0.04

0.05

0.03

0.01

0.12

0.01

0.52

0.09

0.01

0.03

0.12

0.01

1.67

0.62

2.11

0.08

0.17

0.30

0.05

8441Z16.1

8441Z19.1

8441Z2.1

8441Z2.2

8441Z20.1

8441Z22.1

8441Z24.1

8441Z26.1

8441Z3.1

8441Z3.2

8441Z6.1

8441Z7.1

8441Z9.1

8446Z31.1

8446Z31.2

8446Z31.3

8446Z33.1

8446Z33.2

8446Z35.1

8447Z37.1

8447Z37.2

8447Z37.3

8447Z37.4

844-1.13.1

844-1.15.1

844-6.9.1

844-6.9.2

Pbc, %

206

8441Z14.1

Crater

Table 6 (continued)

3906

1885

858

1710

773

713

427

689

358

1613

2719

9409

6389

370

3092

1834

3525

1670

1780

856

870

3571

1230

2023

1681

805

952

1025

U, ppm

3261

1775

3671

7804

978

857

509

1252

523

1675

3512

4039

1588

147

4740

2306

7134

3586

3424

2849

2679

14,600

3684

9510

4580

1758

2765

3237

Th, ppm

0.86

0.97

4.42

4.72

1.31

1.24

1.23

1.88

1.51

1.07

1.33

0.44

0.26

0.41

1.58

1.30

2.09

2.22

1.99

3.44

3.18

4.09

3.09

4.86

2.82

2.26

3.00

3.26

Th/238U

232

135.0

65.5

29.6

59.4

30.6

29.8

21.1

25.3

12.1

51.7

89.7

334.0

240.0

12.4

106.0

57.1

116.0

55.5

59.5

27.6

28.4

114.0

41.7

69.5

57.0

29.4

33.1

34.6

Pb*, ppm

206

254.0

255.0

253.0

255.0

284.0

304.0

355.0

270.0

248.0

236.0

243.0

261.0

274.0

247.0

251.0

229.0

242.0

245.0

246.0

237.0

240.0

235.0

249.0

252.0

250.0

267.0

256.0

249.0

259 247 229 256 233 258 266 201 273 238 272 269 259 250 224 224 263 232 289 286 271 434 93 – 237 307 239 263

±8.0 ±8.4 ±8.0 ±7.9 ±7.8 ±7.3 ±7.5 ±7.5 ±7.7 ±7.7 ±7.6 ±7.2 ±7.9 ±7.8 ±8.7 ±8.1 ±7.6 ±8.0 ±8.0 ±8.5 ±12.0 ±9.6 ±9.3 ±1.4 ±1.9 ±1.5 ±1.1

±31

±60

±80

±43

–

±92

±210

0.300

0.300

0.300

0.300

0.300

0.300

0.400

0.300

0.300

±63 ±37

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

Pb*/235U

207

±24

±18

±15

±46

±49

±25

±22

±18

±26

±26

±36

±46

±20

±42

±32

±21

±61

±44

±27

207 Pb*/206Pb* Age

±7.8

Pb*/238U Age

206

1.4

2.7

3.6

1.9

12.0

5.0

10.0

3.6

4.3

3.6

3.3

3.3

3.8

3.9

3.4

3.3

3.3

3.4

3.4

3.6

3.8

3.3

3.7

3.5

3.4

4.2

3.7

3.4

±%

0.0400

0.0400

0.0400

0.0400

0.0450

0.0480

0.0570

0.0430

0.0390

0.0370

0.0380

0.0410

0.0440

0.0390

0.0400

0.0360

0.0380

0.0390

0.0390

0.0380

0.0380

0.0370

0.0390

0.0400

0.0400

0.0420

0.0410

0.0390

Pb*/238U

206

0.304

0.222

0.212

0.292

0.281

0.640

0.345

0.894

0.764

0.958

0.971

0.979

0.851

0.834

0.948

0.958

0.971

0.942

0.944

0.898

0.850

0.965

0.870

0.917

0.962

0.775

0.857

0.940

КК

(continued)

0.4

0.6

0.8

0.6

3.4

3.2

3.5

3.2

3.3

3.5

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.3

3.2

3.2

3.2

±%

274 O. Petrov et al.

0.43

0.01

0.21

0.01

1.31

0.62

0.92

0.06

0.14

0.16

844-10,11.41.1

844-6.28.1

844-6.28.2

844-6.28.3

844-6.30.1

844-6.30.2

844-6.30.3

844-6.32.1

844-6.32.2

0.17

0.24

0.23

0.16

0.12

0.46

0.12

0.25

0.21

0.22

0.01

0.01

0.01

0.13

0.13

0.07

31-1 11.1

31-1 17.1

31-1 2.1

31-1 2.2

31-1 20.1

31-1 4.1

31-1 8.1

31-1 9.1

31-1 9.2

31-3 1.1

31-3 1.2

31-3 2.1

31-7 1.1

31-7 2.1

31-7 4.1

31-7 5.1

31 (n = 112) Lower Talnakh intrusive

0.42

844-10,11.40.2

Pbc, %

206

844-10,11.40.1

Crater

Table 6 (continued)

7244

1818

3858

9673

1621

3328

1825

5036

4341

6374

4179

4095

4018

7016

3375

5094

3458

6774

534

129

195

187

1651

491

260

622

470

U, ppm

3986

1367

4608

4887

2171

6527

2918

7362

5528

10,719

5640

10,407

4357

8851

4508

3197

4908

5711

964

131

246

124

5434

707

503

2086

663

Th, ppm

0.57

0.78

1.23

0.52

1.38

2.03

1.65

1.51

1.32

1.74

1.39

2.63

1.12

1.30

1.38

0.65

1.47

0.87

1.87

1.05

1.30

0.69

3.40

1.49

2.00

3.46

1.46

Th/238U

232

227.0

60.2

130.0

386.0

49.8

111.0

55.6

146.0

140.0

190.0

115.0

118.0

114.0

188.0

102.0

155.0

104.0

207.0

17.3

4.4

6.7

6.6

52.3

17.2

8.8

21.2

16.0

Pb*, ppm

206

230.5

243.3

248.0

293.0

226.5

245.3

224.1

213.6

236.2

220.1

202.3

211.9

209.4

197.4

223.1

223.3

221.0

225.0

238.0

246.0

250.0

256.0

233.0

257.0

249.0

250.0

249.0

367 196 166 215 220 297 291 268 246 303 242

±4.9 ±5.3 ±5.7 ±5.2 ±1.0 ±0.9 ±5.5 ±8.1 ±7.0 ±5.9 ±5.6

248

±5.8

270

223

±5.9

±5.2

229

±6.5

240

119

±7.1

±5.1

93

±7.1

211

357

±7.4

±4.8

226

±6.1

152

299

±6.8

222

292

±6.9

±5.4

203

±5.4

291

±6.7

±22

±48

±31

±11

±35

±21

0.256

0.278

0.276

0.330

0.257

0.280

0.246

0.234

±47 ±51

0.254

0.240

0.237

0.238

0.232

0.216

0.238

0.246

0.200

0.200

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

0.300

Pb*/235U

207

±47

±27

±89

±43

±42

±32

±47

±37

±28

±24

±69

±240

±210

±280

±28

±69

±69

±90

±76

207 Pb*/206Pb* Age

±6.6

Pb*/238U Age

206

2.6

3.2

3.2

2.9

2.9

1.0

2.3

3.2

3.2

2.7

4.7

3.1

3.1

2.8

3.2

2.9

2.9

2.9

4.1

11.0

9.3

13.0

2.9

4.1

4.1

4.7

4.3

±%

0.0360

0.0380

0.0390

0.0460

0.0360

0.0390

0.0350

0.0340

0.0370

0.0350

0.0320

0.0330

0.0330

0.0310

0.0350

0.0350

0.0350

0.0360

0.0380

0.0390

0.0400

0.0410

0.0370

0.0410

0.0390

0.0400

0.0390

Pb*/238U

206

0.930

0.763

0.903

0.987

0.850

0.373

0.205

0.772

0.773

0.903

0.527

0.800

0.805

0.874

0.777

0.842

0.908

0.930

0.684

0.278

0.304

0.231

0.911

0.667

0.682

0.573

0.630

КК

(continued)

2.5

2.5

2.9

2.8

2.5

2.4

2.5

2.5

2.5

2.5

2.5

2.5

2.5

2.4

2.5

2.5

2.7

2.7

2.8

2.9

2.8

2.9

2.7

2.7

2.8

2.7

2.7

±%

Isotope Chronology of Geological Processes 275

0.08

0.36

0.33

0.07

0.26

0.02

0.24

0.29

0.44

0.12

0.45

0.11

0.31

0.26

0.09

0.09

0.18

0.09

0.16

0.21

0.51

0.44

0.15

0.36

0.21

0.60

0.01

0.01

31-7 6.1

31-7 9.1

31-7 9.2

31-9 1.1

31-9 1.2

31-9 2.1

31-9 3.1

31-9 4.1

31-10 1.1

31-10 4.1

31-11 1.1

31-11 2.1

31-13 10.1

31-13 11.1

31-13 11.2

31-13 12.1

31-13 14.1

31-13 14.2

31-13 19.1

31-13 2.1

31-13 20.1

31-13 21.1

31-13 23.1

31-13 25.1

31-13 27.1

31-13 27.2

31-13 28.1

Pbc, %

206

31-7 5.2

Crater

Table 6 (continued)

1891

10,722

1976

3901

1726

2520

968

1718

4562

2539

2107

1214

1422

1817

1926

1303

2140

1819

1460

1305

1487

3679

4188

379

4323

3292

1669

3558

U, ppm

1969

38,408

4367

5640

2513

7789

1510

4351

6712

4042

4457

2958

1058

1838

4991

2547

3430

3558

1195

2593

2265

3018

4148

285

2147

2198

1151

3956

Th, ppm

1.08

3.70

2.28

1.49

1.51

3.19

1.61

2.62

1.52

1.65

2.19

2.52

0.77

1.05

2.68

2.02

1.66

2.02

0.85

2.05

1.57

0.85

1.02

0.78

0.51

0.69

0.71

1.15

Th/238U

232

69.0

380.0

60.5

130.0

60.9

75.0

34.5

62.6

160.0

86.4

71.1

37.0

46.0

58.0

64.0

41.1

63.2

54.9

47.2

39.5

45.3

109.0

123.0

11.4

139.0

103.0

53.1

111.0

Pb*, ppm

206

269.0

260.4

224.3

244.8

258.8

220.0

260.8

266.5

256.7

250.1

248.0

225.0

239.0

234.0

245.0

232.0

217.6

221.8

238.0

222.5

223.9

217.6

217.0

221.3

237.3

228.8

233.7

229.2

233 173 116 207 464 260 183 185 145 289 116 218 150 204 231 217 307 298 237 211 247 159 250 126 238 157 256 254

±5.7 ±5.6 ±5.7 ±5.9 ±5.3 ±5.3 ±5.5 ±5.4 ±5.8 ±5.4 ±5.3 ±5.7 ±6.9 ±6.6 ±6.7 ±6.4 ±7.5 ±7.6 ±7.8 ±8.1 ±8.0 ±6.2 ±7.9 ±7.5 ±6.9 ±7.9 ±7.6

±27

±16

±95

±50

±75

±36

±89

0.302

0.292

0.240

0.272

0.274

0.245

0.280

0.298

0.282

±32 ±71

0.278

0.283

0.257

0.263

0.259

0.268

0.248

0.239

0.233

0.270

0.237

0.243

0.236

0.243

0.271

0.260

0.241

0.252

0.254

Pb*/235U

207

±38

±36

±54

±40

±40

±50

±79

±46

±70

±54

±77

±69

±47

±25

±87

±29

±64

±68

±30

207 Pb*/206Pb* Age

±5.6

Pb*/238U Age

206

3.1

3.2

5.1

3.8

4.4

3.3

4.9

4.4

3.4

3.5

3.5

3.7

3.4

3.4

3.6

4.2

3.2

3.9

3.4

4.1

3.9

3.2

2.7

4.8

2.8

3.7

3.8

2.8

±%

0.0430

0.0410

0.0350

0.0390

0.0410

0.0350

0.0410

0.0420

0.0410

0.0400

0.0390

0.0360

0.0380

0.0370

0.0390

0.0370

0.0340

0.0350

0.0380

0.0350

0.0350

0.0340

0.0340

0.0350

0.0370

0.0360

0.0370

0.0360

Pb*/238U

206

0.926

0.976

0.610

0.821

0.699

0.880

0.635

0.710

0.912

0.881

0.891

0.771

0.856

0.859

0.800

0.599

0.780

0.645

0.726

0.605

0.640

0.775

0.915

0.564

0.891

0.672

0.646

0.884

КК

(continued)

2.9

3.1

3.1

3.1

3.1

2.9

3.1

3.1

3.1

3.1

3.1

2.9

2.9

2.9

2.9

2.5

2.5

2.5

2.5

2.5

2.5

2.5

2.5

2.7

2.5

2.5

2.5

2.5

±%

276 O. Petrov et al.

0.66

0.06

0.38

0.25

0.01

0.17

0.03

0.11

0.01

0.17

0.26

0.04

0.01

0.04

0.01

1.44

0.16

0.13

0.12

0.66

0.13

0.23

1.02

0.01

0.55

0.11

0.15

0.64

31-13 34.1

31-13 35.1

31-13 38.1

31-13 38.2

31-13 4.2

31-13 42.1

31-13 44.1

31-13 46.1

31-13 46.2

31-13 48.1

31-13 5.1

31-13 50.1

31-13 50.2

31-13 53.1

31-13 54.1

31-13 54.2

31-13 54.3

31-13 56.1

31-13 6.1

31-13 7.1

31-13 8.1

31-13 8.2

31-13 9.1

31-13 9.2

31-16.13.1

31-16.17.1

31-16.18.1

Pbc, %

206

31-13 28.2

Crater

Table 6 (continued)

1103

970

1799

418

1174

887

3104

1988

794

3780

2875

3521

1367

3008

1826

2601

1635

1923

4047

5965

3196

1613

616

2164

2778

2143

4435

823

U, ppm

1651

1668

3222

753

984

1725

7453

8244

1393

4256

6268

4281

1377

4469

2712

3884

4407

1347

5881

8346

4413

2276

1726

4132

6044

3538

4266

1213

Th, ppm

1.55

1.78

1.85

1.86

0.87

2.01

2.48

4.29

1.81

1.16

2.25

1.26

1.04

1.53

1.53

1.54

2.79

0.72

1.50

1.45

1.43

1.46

2.90

1.97

2.25

1.71

0.99

1.52

Th/238U

232

37.5

32.5

65.2

16.6

40.5

37.3

109.0

67.9

28.6

130.0

104.0

121.0

49.9

100.0

65.2

90.2

53.0

72.4

140.0

208.0

111.0

53.0

22.9

76.2

95.4

73.4

145.0

28.0

Pb*, ppm

206

248.5

246.0

265.9

288.9

254.2

304.7

257.8

250.9

263.2

253.3

266.3

252.3

264.6

245.4

262.3

255.0

240.0

275.9

254.0

256.7

255.7

242.0

273.1

259.3

252.0

250.9

239.9

245.0

290 239 212 231 311 232 272 266 275 225 223 246 302 301 313 164 248 279 240 158 247 126 93 359 460 279 362 34

±7.3 ±7.6 ±7.6 ±7.9 ±8.4 ±6.8 ±7.7 ±7.7 ±7.7 ±8.4 ±7.0 ±7.7 ±8.0 ±7.4 ±8.2 ±7.6 ±8.1 ±7.7 ±8.1 ±7.6 ±7.8 ±9.5 ±8.1 ±9.0 ±6.1 ±6.5 ±5.8

±150

±64

±36

±94

±39

±220

±49

0.253

0.288

0.301

0.355

0.298

0.320

0.273

0.280

0.283

±110 ±51

0.282

0.302

0.282

0.285

0.282

0.300

0.292

0.267

0.305

0.281

0.290

0.288

0.272

0.303

0.298

0.279

0.276

0.266

0.278

Pb*/235U

207

±36

±43

±32

±140

±25

±35

±27

±30

±58

±32

±19

±30

±31

±79

±30

±51

±60

±28

±110

207 Pb*/206Pb* Age

±7.0

Pb*/238U Age

206

6.8

3.9

2.8

5.3

3.7

9.7

3.7

3.8

5.8

3.5

3.6

3.4

6.9

3.3

3.5

3.3

3.2

4.0

3.4

3.2

3.3

3.2

4.7

3.4

3.8

4.0

3.3

5.6

±%

0.0390

0.0390

0.0420

0.0460

0.0400

0.0480

0.0410

0.0400

0.0420

0.0400

0.0420

0.0400

0.0420

0.0390

0.0420

0.0400

0.0380

0.0440

0.0400

0.0410

0.0410

0.0380

0.0430

0.0410

0.0400

0.0400

0.0380

0.0390

Pb*/238U

206

0.349

0.685

0.830

0.600

0.883

0.331

0.828

0.815

0.543

0.895

0.854

0.912

0.457

0.942

0.896

0.933

0.915

0.779

0.913

0.965

0.922

0.907

0.675

0.923

0.815

0.768

0.929

0.519

КК

(continued)

2.4

2.7

2.3

3.2

3.2

3.2

3.1

3.1

3.1

3.1

3.1

3.1

3.2

3.1

3.1

3.1

3.0

3.1

3.1

3.1

3.1

2.9

3.1

3.1

3.1

3.1

3.1

2.9

±%

Isotope Chronology of Geological Processes 277

0.31

0.46

0.14

0.23

4.35

0.85

0.08

0.13

0.07

0.10

0.09

1.29

0.01

0.09

0.21

0.48

0.66

0.06

3.78

0.07

1.18

1.07

1.09

0.02

0.15

0.07

0.22

0.59

31-16.19.2

31-16.2.1

31-16.29.1

31-16.39.1

31-16.39.2

31-16.43.1

31-16.44.1

31-16.5.1

31-16.51.1

31-16.52.1

31-16.55.1

31-16.6.1

31-16.61.1

31-16.65.1

31-16.71.1

31-16.72.1

31-16.72.2

31-16.73.1

31-16.74.1

31-16.81.1

31-16.81.2

31-16.9.1

31-16 10.1

31-16 20.1

31-16 20.2

31-16 22.1

31-16 22.2

Pbc, %

206

31-16.19.1

Crater

Table 6 (continued)

145

323

393

1808

3918

879

770

745

6192

1244

3345

1004

1505

287

3848

590

569

1399

1419

838

1507

1790

311

750

678

1117

791

1016

U, ppm

130

355

359

2915

5539

1185

8746

7380

2920

1739

3892

1140

3331

984

9738

2230

1890

4110

3479

896

3369

2992

402

1244

1599

2413

2630

2775

Th, ppm

0.9

1.1

0.9

1.7

1.5

1.39

11.74

10.24

0.49

1.44

1.20

1.17

2.29

3.55

2.61

3.90

3.43

3.04

2.53

1.10

2.31

1.73

1.34

1.71

2.44

2.23

3.44

2.82

Th/238U

232

5.3

11.6

10.6

56.6

138.0

32.7

22.9

24.1

194.0

44.8

106.0

34.3

48.0

9.87

119.0

21.5

19.0

47.6

44.8

31.2

53.9

61.7

9.1

27.1

21.4

38.9

26.0

33.8

Pb*, ppm

206

267.0

264.0

198.0

230.0

260.0

270.6

217.3

235.6

230.4

254.7

232.8

249.6

233.7

252.8

227.8

268.0

243.2

250.4

232.2

273.0

262.5

253.4

213.2

254.2

231.7

255.7

240.8

244.3

206 200 224 183 – 125 213 311 383 258 295 91 492 259 431 156 154 304 349 269 – – – 238 242 273 331 274

±5.8 ±5.9 ±5.5 ±6.2 ±5.6 ±5.8 ±6.1 ±6.4 ±5.4 ±5.8 ±5.9 ±6.4 ±5.2 ±6.2 ±5.4 ±5.9 ±5.3 ±6.2 ±5.3 ±5.7 ±5.2 ±6.4 ±14.0 ±13.0 ±11.0 ±15.0 ±15.0

±210

±93

±60

±37

±18

–

–

0.301

0.305

0.223

0.256

0.289

0.260

0.215

0.235

0.259

±22 –

0.297

0.266

0.267

0.250

0.306

0.255

0.334

0.254

0.285

0.260

0.324

0.301

0.279

0.225

0.229

0.251

0.283

0.263

0.268

Pb*/235U

207

±430

±29

±130

±68

±93

±31

±62

±230

±47

±43

±49

±47

±41

±340

–

±84

±55

±120

±73

207 Pb*/206Pb* Age

±5.7

Pb*/238U Age

206

11.0

7.0

6.3

5.9

5.7

7.0

7.4

9.6

2.5

19.0

2.7

6.1

3.7

4.9

2.7

3.7

10.0

3.1

3.0

3.2

3.1

2.9

15.0

14.0

4.3

3.3

5.7

3.9

±%

0.0420

0.0420

0.0310

0.0360

0.0410

0.0430

0.0340

0.0370

0.0360

0.0400

0.0370

0.0390

0.0370

0.0400

0.0360

0.0420

0.0380

0.0400

0.0370

0.0430

0.0420

0.0400

0.0340

0.0400

0.0370

0.0400

0.0380

0.0390

Pb*/238U

206

0.534

0.811

0.908

0.963

0.991

0.346

0.331

0.254

0.926

0.130

0.876

0.395

0.633

0.512

0.864

0.657

0.245

0.753

0.787

0.742

0.753

0.796

0.180

0.180

0.554

0.708

0.430

0.607

КК

(continued)

5.8

5.7

5.7

5.7

5.6

2.4

2.5

2.4

2.3

2.5

2.3

2.4

2.4

2.5

2.3

2.5

2.5

2.4

2.4

2.4

2.4

2.3

2.7

2.5

2.4

2.4

2.4

2.4

±%

278 O. Petrov et al.

0.07

0.16

0.10

0.06

0.01

0.12

0.06

0.01

0.01

0.21

0.01

31-16 26.2

31-16 31.1

31-16 37.1

31-16 38.1

31-16 41.1

31-16 47.1

31-16 49.1

31-16 54.1

31-16 67.1

31-16 78.1

0.26

0.24

0.04

0.15

0.24

0.27

0.02

0.11

0.03

0.01

0.03

0.11

0.03

0.18

0.06

27-1.1.1

27-1.2.1

27-1.3.1

27-1.3.2

27-1.4.1

27-1.4.2

27-1.5.1

27-1.6.1

27-1.7.1

27-3-1.1

27-3-1.2

27-3-2.1

27-3-3.1

27-4.10.1

27-4.11.1

27 (n = 60) Zub-Marksheidersky intrusive

0.01

31-16 26.1

Pbc, %

206

31-16 25.1

Crater

Table 6 (continued)

1372

4374

3437

3541

2665

4928

1124

326

707

453

506

1522

793

501

205

803

1262

288

4094

1192

2231

1375

2477

1239

1430

1871

316

U, ppm

1039

5775

1119

795

508

1797

1015

224

517

349

357

1549

697

249

85

747

3248

265

5370

1339

4377

1902

4390

2737

1890

7127

338

Th, ppm

0.78

1.36

0.34

0.23

0.20

0.38

0.93

0.71

0.76

0.80

0.73

1.05

0.91

0.51

0.43

1.0

2.7

1.0

1.4

1.2

2.0

1.4

1.8

2.3

1.4

3.9

1.1

Th/238U

232

36.0

121.0

108.0

121.0

80.1

175.0

35.3

10.0

20.7

12.2

14.4

42.8

24.3

16.0

5.5

27.8

40.1

10.0

141.0

40.0

72.5

48.8

91.3

44.2

52.5

58.6

12.7

Pb*, ppm

206

193.9

203.2

232.5

251.4

221.7

260.5

231.1

225.0

216.2

198.9

209.7

207.3

225.3

234.9

198.5

255.0

233.0

256.0

253.0

247.0

239.0

261.0

271.0

262.0

270.0

231.0

295.0

280 319 208 274 277 357 214 431 248 294

±3.9 ±4.2 ±3.9 ±4.3 ±3.7 ±4.2 ±3.9 ±3.4 ±3.3

235

±14.0

±3.8

222

±13.0

312

347

±14.0

±3.8

264

±14.0

238

265

±14.0

±3.5

243

±13.0

288

261

±14.0

±4.0

238

±15.0

295

226

±15.0

362

223

±15.0

±4.2

197

±4.0

357

±13.0

±39

±35

±22

±32

±27

±21

0.220

0.226

0.281

0.276

0.259

0.295

0.261

0.246

±81 ±38

0.248

0.224

0.240

0.230

0.255

0.267

0.232

0.283

0.257

0.298

0.285

0.277

0.266

0.293

0.301

0.290

0.298

0.252

0.347

Pb*/235U

207

±48

±110

±100

±54

±46

±83

±120

±56

±58

±64

±16

±36

±31

±37

±28

±50

±34

±36

±66

207 Pb*/206Pb* Age

±16.0

Pb*/238U Age

206

2.4

2.3

2.0

2.2

2.1

1.9

2.4

4.0

2.8

5.3

4.8

2.9

2.7

4.1

5.8

6.2

6.2

6.4

5.7

5.9

5.8

5.9

5.8

6.1

5.8

5.9

6.4

±%

0.0305

0.0320

0.0367

0.0398

0.0350

0.0412

0.0365

0.0355

0.0341

0.0313

0.0331

0.0327

0.0356

0.0371

0.0313

0.0400

0.0370

0.0410

0.0400

0.0390

0.0380

0.0410

0.0430

0.0420

0.0430

0.0370

0.0470

Pb*/238U

206

0.710

0.744

0.860

0.775

0.816

0.880

0.724

0.473

0.652

0.363

0.381

0.588

0.665

0.447

0.351

0.919

0.915

0.896

0.992

0.964

0.972

0.963

0.977

0.934

0.968

0.965

0.889

КК

(continued)

1.7

1.7

1.7

1.7

1.7

1.7

1.7

1.9

1.8

1.9

1.8

1.7

1.8

1.8

2.0

5.7

5.7

5.7

5.6

5.7

5.7

5.7

5.7

5.7

5.7

5.7

5.7

±%

Isotope Chronology of Geological Processes 279

0.08

0.52

0.09

0.93

27-6 3.2

27-6 6

27-6 7

27-6 9

0.88

0.14

27-6 3.1

27-7-11.1

0.01

27-5.2.2

0.25

0.06

27-5.2.1

27-7.9.2

0.01

27-5-3.1.2

0.05

0.08

27-5-3.1.1

27-7.9.1

0.01

27-5-1.1

0.09

0.02

27-4.8.1

27-7.7.1

0.13

27-4.7.1

0.10

0.15

27-4.6.1

27-7.2.2

0.01

27-4.5.1

0.25

0.10

27-4.4.2

27-7.2.1

0.15

27-4.4.1

0.91

0.04

27-4.2.1

0.13

0.89

27-4.14.1

27-7.10.1

0.11

27-6 10

0.11

27-4.12.2

Pbc, %

206

27-4.12.1

Crater

Table 6 (continued)

1085

3233

3401

1797

395

556

1205

244

1335

1353

373

496

1446

11,409

6382

24,685

6770

4180

12,249

8889

11,095

11,403

8745

1566

7673

1416

9171

10,319

U, ppm

3356

7326

5209

1358

240

347

2276

96

2321

2843

546

426

1472

28,326

12,937

22,110

5690

7248

14,654

18,458

22,871

26,926

13,825

1213

10,403

1299

9623

12,064

Th, ppm

3.20

2.34

1.58

0.78

0.63

0.64

1.95

0.40

1.80

2.17

1.51

0.89

1.05

2.57

2.09

0.93

0.87

1.79

1.24

2.15

2.13

2.44

1.63

0.80

1.40

0.95

1.08

1.21

Th/238U

232

32.4

104.0

126.0

61.0

12.9

19.1

43.2

8.4

45.8

46.8

12.7

17.4

47.0

458.0

203.0

899.0

189.0

127.0

433.0

276.0

348.0

380.0

252.0

45.1

261.0

36.3

272.0

323.0

Pb*, ppm

206

218.6

237.4

272.2

249.6

239.8

252.3

263.0

249.4

250.0

254.0

249.1

258.0

238.9

294.5

234.0

267.7

205.8

224.4

259.6

228.8

230.5

245.4

212.5

212.1

250.1

187.8

218.7

230.2

±56 –

340 248 262 247 260 274 279 254 238 243 236 231 260 123 316 233 216 – 262 287 244 275 268 264 206 184

±4.0 ±4.1 ±4.5 ±3.7 ±4.0 ±3.8 ±3.8 ±4.2 ±3.7 ±4.0 ±4.5 ±6.6 ±8.2 ±4.9 ±5.9 ±5.6 ±5.1 ±5.2 ±6.1 ±7.5 ±7.2 ±7.0 ±7.0 ±7.6 ±6.7 ±3.8

±110

±47

±21

±51

±67

±66

±53

±330

±210

±100

±69

±11

±22

±19

±23

±20

±12

±23

±16

±12

±22

±44

±17

±92

±21

267

±35

265

±4.0

207 Pb*/206Pb* Age

±4.6

Pb*/238U Age

206

0.237

0.260

0.306

0.281

0.271

0.281

0.299

0.280

0.243

0.280

0.276

0.297

0.252

0.332

0.259

0.298

0.228

0.249

0.291

0.258

0.260

0.275

0.236

0.237

0.279

0.217

0.245

0.258

Pb*/235U

207

4.9

3.5

3.0

3.6

4.2

4.1

3.7

15.0

10.0

3.2

9.4

5.1

3.6

2.9

3.0

1.9

2.2

1.9

1.7

1.9

1.8

1.7

2.0

2.9

1.8

4.6

2.1

2.5

±%

0.0345

0.0375

0.0431

0.0395

0.0379

0.0399

0.0416

0.0395

0.0395

0.0402

0.0394

0.0408

0.0378

0.0467

0.0370

0.0424

0.0324

0.0354

0.0411

0.0361

0.0364

0.0388

0.0335

0.0335

0.0396

0.0296

0.0345

0.0364

Pb*/238U

206

0.361

0.817

0.951

0.790

0.715

0.714

0.780

0.171

0.203

0.648

0.246

0.460

0.579

0.987

0.950

0.900

0.893

0.888

0.956

0.857

0.921

0.957

0.879

0.744

0.912

0.471

0.899

0.800

КК

(continued)

1.8

2.9

2.9

2.9

3.0

2.9

2.9

2.5

2.1

2.0

2.3

2.3

2.1

2.9

2.9

1.7

2.0

1.7

1.7

1.7

1.7

1.7

1.8

2.2

1.7

2.2

1.9

2.0

±%

280 O. Petrov et al.

0.06

0.19

0.60

0.01

0.05

0.19

0.45

0.01

0.02

0.03

0.07

0.13

0.24

0.09

0.19

0.38

27-7-3.1.2

27-7-4.1

27-7-5.1

27-7-6.1

27-7-8.1

27-7-8.2

27-13.1.1

27-13.1.2

27-13.1.3

27-13.2.1

27-14.1.1

27-14.1.2

27-14.2.1

27-14.3.1

27-14.3.2

0.08

0.68

0.01

0.11

0.16

0.23

0.15

0.20

0.51

0.58

4-3 1

4-6 1

4-6 2

4-6 6

4-6 7

4-8 1

4-9 1

4-9 3

4-9 8.1

4-9 8.2

4 Imangda intrusive (n = 18)

0.61

27-7-3.1.1

Pbc, %

206

27-7-11.2

Crater

Table 6 (continued)

1859

2884

1695

2260

1273

7653

1619

3891

2377

5147

640

1154

496

413

272

8232

5282

5300

3317

2630

1232

2729

420

667

1661

444

569

U, ppm

7604

3236

2961

217

1127

24,090

3931

7574

7425

7892

427

889

264

231

132

14,073

12,717

12,937

5575

10,596

1236

10,299

337

988

5592

605

872

Th, ppm

4.23

1.16

1.81

0.10

0.91

3.25

2.51

2.01

3.23

1.58

0.69

0.80

0.55

0.58

0.50

1.77

2.49

2.52

1.74

4.16

1.04

3.90

0.83

1.53

3.48

1.41

1.58

Th/238U

232

62.0

92.1

53.6

80.8

42.0

228.0

51.4

120.0

77.3

155.0

18.4

35.8

15.9

10.9

7.8

253.0

169.0

151.0

113.0

70.9

30.5

79.1

12.7

19.4

51.9

15.9

16.0

Pb*, ppm

206

244.1

234.1

232.7

262.4

242.4

219.0

233.8

227.0

237.8

222.3

211.9

228.3

235.2

194.1

210.7

226.0

235.6

209.9

250.9

198.4

182.6

213.9

221.9

213.6

229.8

262.5

206.4

214 264

±2.9 ±3.1

63

±3.7

230

183

±3.9

±3.0

116

±4.2

255

239

±3.6

±3.2

243

±4.0

192

272

±4.0

±3.2

274

±3.9

191

248

±4.5

198

316

±4.9

±2.6

274

±3.3

±2.9

261

±3.2

218

230

±3.6

±2.7

193

±4.0

363

135

±3.8

211

168

±3.9

±3.0

227

±2.6

111

±4.9

±100

±74

±84

±64

±73

±52

0.274

0.257

0.257

0.294

0.264

0.238

0.255

0.250

±28 ±59

0.279

0.244

0.218

0.247

0.248

0.215

0.234

0.254

0.266

0.234

0.288

0.223

0.204

0.236

0.241

0.226

0.247

0.291

0.216

Pb*/235U

207

±74

±30

±97

±62

±68

±95

±93

±22

±21

±24

±42

±53

±51

±31

±64

±170

±60

±65

±110

207 Pb*/206Pb* Age

±3.7

Pb*/238U Age

206

4.7

3.4

3.9

3.1

3.4

2.5

2.8

1.7

3.5

1.8

4.4

3.2

3.4

4.5

4.5

2.0

1.9

2.4

2.7

2.9

2.8

2.2

3.3

7.4

3.1

3.4

5.1

±%

0.0386

0.0370

0.0368

0.0416

0.0383

0.0346

0.0369

0.0359

0.0376

0.0351

0.0334

0.0361

0.0372

0.0306

0.0332

0.0357

0.0372

0.0331

0.0397

0.0313

0.0287

0.0337

0.0350

0.0337

0.0363

0.0416

0.0325

Pb*/238U

206

0.2749

0.3722

0.3360

0.414

0.390

0.471

0.449

0.708

0.358

0.679

0.405

0.552

0.532

0.413

0.436

0.886

0.878

0.903

0.729

0.590

0.622

0.787

0.556

0.246

0.558

0.559

0.356

КК

(continued)

1.3

1.3

1.3

1.3

1.3

1.2

1.3

1.2

1.3

1.2

1.8

1.8

1.8

1.9

2.0

1.8

1.7

2.2

2.0

1.7

1.8

1.7

1.8

1.8

1.7

1.9

1.8

±%

Isotope Chronology of Geological Processes 281

0.27

0.09

0.45

0.32

0.08

0.54

0.26

4-9 11

4-9 13

4-10 2

4-10 4

4-10 7

4-10 8

0.21

0.14

0.25

0.40

0.19

0.14

0.01

1.68

0.12

0.36

0.05

0.01

0.08

7.54

0.12

0.14

0.17

0.03

0.01

CH-9_2

CH-9_3

CH-9_4

CH-9-5

CH-9-6

CH-9-7

CH-9-8

CH-10_7

CH-10_8

CH-11_1.1

CH-11_1.2

CH-11_2.1

CH-11_3.1

CH-11_3.2

CH-11_4.1

CH-11_4.2

CH-11_5.1

CH-11_5.2

CH-11_6.1

Chernogorsk intrusive (n = 21)

0.03

4-9 10

Pbc, %

206

4-9 9

Crater

Table 6 (continued)

363

2859

846

798

387

434

715

461

498

481

1732

727

1616

1918

487

1557

3412

735

1179

6348

952

2457

2291

1819

2679

3370

5590

U, ppm

384

6668

1251

2667

877

1749

2003

794

1627

762

3106

1504

4212

3409

319

3276

4480

1109

2198

8914

1713

5433

5089

151

4480

10 161

10 957

Th, ppm

1.09

2.41

1.53

3.45

2.34

4.16

2.89

1.78

3.37

1.64

1.85

2.14

2.69

1.84

0.68

2.17

1.36

1.56

1.93

1.45

1.86

2.28

2.30

0.09

1.73

3.12

2.03

Th/238U

232

12.0

96.6

28.4

27.0

12.9

18.8

23.9

15.1

16.6

15.9

56.6

24.1

49.7

63.5

16.3

51.2

109.0

24.8

39.1

199.0

31.7

75.2

70.1

64.7

87.9

110.0

183.0

Pb*, ppm

206

242.6

248.7

247.0

248.3

245.0

292.5

246.2

241.2

245.8

242.4

240.1

240.1

227.0

243.5

246.6

241.3

234.9

248.3

243.7

230.8

243.6

225.5

224.8

260.3

241.6

240.0

240.8

222 254 218 246 – 207 157 230 303 256 1280 223 239 273 281 315

±3.5 ±3.1 ±2.9 ±5.4 ±4.9 ±2.0 ±1.9 ±1.8 ±1.7 ±5.4 ±2.3 ±1.5 ±1.7 ±0.9 ±2.4

238

±2.8

±3.1

177

±3.4

222

185

±2.8

±7.2

255

±3.5

274

332

±3.3

274

254

±3.0

±3.3

209

±3.2

215

±2.9

±63

±24

±66

±60

±75

±1400

±51

±53

±52

±110

±61

–

±58

±63

±98

±110

±96

±65

±82

±68

±200

±45

±84

±79

±50

±69

±25

207 Pb*/206Pb* Age

±2.9

Pb*/238U Age

206

0.279

0.282

0.279

0.276

0.270

0.530

0.276

0.275

0.272

0.260

0.263

0.204

0.253

0.268

0.276

0.266

0.259

0.280

0.275

0.256

0.263

0.244

0.251

0.302

0.270

0.263

0.265

Pb*/235U

207

3.0

1.1

3.0

2.7

3.4

70.0

2.3

2.4

2.4

4.6

3.4

19.0

2.8

3.0

4.5

4.9

5.2

3.1

3.8

3.2

8.7

2.3

4.0

3.7

2.5

3.2

1.6

±%

0.0383

0.0393

0.0391

0.0393

0.0387

0.0464

0.0389

0.0381

0.0389

0.0383

0.0380

0.0380

0.0358

0.0385

0.0390

0.0381

0.0371

0.0393

0.0385

0.0365

0.0385

0.0356

0.0355

0.0412

0.0382

0.0379

0.0381

Pb*/238U

206

0.342

0.341

0.233

0.229

0.278

0.027

0.304

0.305

0.332

0.184

0.614

0.122

0.455

0.431

0.323

0.264

0.600

0.435

0.347

0.3915

0.1651

0.5493

0.4031

0.3477

0.4991

0.3870

0.7517

КК

(continued)

1.0

0.4

0.7

0.6

0.9

1.9

0.7

0.7

0.8

0.9

2.1

2.3

1.3

1.3

1.5

1.3

3.1

1.4

1.3

1.2

1.4

1.3

1.6

1.3

1.2

1.2

1.2

±%

282 O. Petrov et al.

0.02

0.78

0.76

0.38

0.21

0.18

0.60

0.30

0.09

0.21

0.01

0.21

0.01

0.87

25-4 2.1

25-4 4.1

25-4 5.1

25-4 5.2

25-46

25-4 7.1

25-4 9.1

25-44 2

25-44 4

25-44 5.1

25-44 6.1

25-9-10 1.1

25-9-10 2.1

0.02

0.08

0.27

0.01

0.22

29-5,6 1

29-9 1.1

29-9 2.1

29-9 2.2

29-9 2.3

29 Vologochan intrusive (n = 19)

0.71

2.96

25-35 1.1

1.45

0.17

25-31 3.1

25-4 1.1

0.15

25-31 2

25-35 2

0.10

25-20 1.1

25 (n = 19) South Pyasina intrusive

0.52

CH-11_8.1

Pbc, %

206

CH-11_7.1

Crater

Table 6 (continued)

1783

1770

3180

3152

9495

1298

3732

3315

1342

2025

1071

2078

770

2009

1088

1367

1436

1155

206

311

397

1841

745

1231

2766

807

U, ppm

2178

2160

5180

2302

14,553

1314

4789

6531

2695

5682

886

4683

1729

5247

2288

2137

3130

2023

90

858

1417

5523

2968

2632

5616

1131

Th, ppm

1.26

1.26

1.68

0.75

1.58

1.05

1.33

2.04

2.07

2.90

0.85

2.33

2.32

2.70

2.17

1.62

2.25

1.81

0.45

2.85

3.68

3.10

4.11

2.21

2.10

1.45

Th/238U

232

58.0

62.5

98.1

111.0

351.0

44.3

134.0

113.0

46.6

64.8

30.8

70.5

25.4

62.8

35.6

45.2

47.5

39.1

7.1

10.3

13.8

60.8

25.5

42.7

93.8

27.8

Pb*, ppm

206

239.0

260.0

227.0

260.0

271.6

248.9

264.3

249.7

256.5

235.1

211.9

248.8

242.0

229.9

240.3

242.7

241.9

247.1

250.6

241.8

247.9

242.5

251.6

254.8

249.6

251.8

204 223 222 232 200 447 184 275 –

±2.9 ±5.2 ±5.0 ±2.8 ±3.0 ±5.3 ±5.0 ±5.2 ±5.4

214

290

±3.3

±13.0

267

±3.3

218

213

±3.2

±14.0

83

±5.3

261

124

±6.3

±13.0

364

±3.9

259

–

±9.0

237

216

±4.9

±14.0

301

±0.8

257

±3.4

246

±5.2

298

±1.1

±55

±28

±49

±31

±14

0.263

0.286

0.254

0.289

0.305

0.249

0.299

±32 –

0.271

0.313

0.257

0.234

0.274

0.267

0.251

0.273

0.273

0.266

0.257

0.265

0.284

0.180

0.267

0.287

0.286

0.278

0.287

Pb*/235U

207

±85

±130

±86

±65

±81

±230

±76

±79

±94

±140

±300

±450

±170

–

±71

±68

±58

±23

±130

207 Pb*/206Pb* Age

±1.7

Pb*/238U Age

206

6.1

5.8

6.0

5.8

0.7

14.0

2.4

4.2

6.3

3.9

3.1

4.1

10.0

3.5

3.7

4.3

6.3

13.0

19.0

7.6

77.0

3.7

3.3

3.3

1.1

5.8

±%

0.0378

0.0411

0.0358

0.0411

0.0430

0.0394

0.0419

0.0395

0.0406

0.0371

0.0334

0.0394

0.0383

0.0363

0.0380

0.0384

0.0382

0.0391

0.0396

0.0382

0.0392

0.0383

0.0398

0.0403

0.0395

0.0398

Pb*/238U

206

0.921

0.978

0.936

0.972

0.427

0.161

0.821

0.488

0.337

0.329

0.431

0.503

0.219

0.363

0.378

0.316

0.214

0.167

0.132

0.216

0.048

0.563

0.418

0.633

0.395

0.121

КК

(continued)

5.7

5.7

5.7

5.7

0.3

2.2

2.0

2.0

2.1

1.3

1.4

2.0

2.2

1.3

1.4

1.4

1.3

2.2

2.6

1.6

3.7

2.1

1.4

2.1

0.4

0.7

±%

Isotope Chronology of Geological Processes 283

0.01

0.63

1.48

0.36

0.06

0.07

1.12

0.04

0.01

0.04

0.34

0.69

0.02

29-9 10.1

29-9 10.2

29-9 16.1

29-9 19.1

29-9 21.1

29-16.1.1

29-16 2

29-16 4

29-16 6

29-17 1.1

29-17 1.2

29-17 2.1

2200

769

573

996

1659

1242

1665

3416

1726

1480

160

484

3878

3723

U, ppm

2595

1940

1615

797

1963

2783

7373

3307

2289

3150

382

964

6698

6314

Th, ppm

1.22

2.61

2.91

0.83

1.22

2.31

4.57

1.00

1.37

2.20

2.47

2.06

1.78

1.75

Th/238U

232

0.34

0.63

0.55

0.58

1.13

2.54

0.64

0.71

0.69

0.01

2.20

0.88

48-18 1,1

48-18 1,2

48-18 2,1

48-18 2,2

48-18 21,1

48-18 21,2

48-18 5,1

48-18 5,2

48-18 5,3

48-25 6.1

48-25 6.2

48-30 1.1

MD-48 Mikchangda intrusive

2174

795

1087

2492

1192

1566

2366

3597

2491

3042

2028

4230

3366

1101

1949

3104

919

1162

4068

4131

3403

3227

1943

4899

1.60

1.43

1.85

1.29

0.80

0.77

1.78

1.19

1.41

1.10

0.99

1.20

MD-48, S-1, TP-43 Mikchangda, Binyuda, Dyumptalej intrusives (n = 25)

0.73

29-9 8.1

Pbc, %

206

29-9 7

Crater

Table 6 (continued)

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

67.6

25.8

17.3

45.2

51.4

41.5

56.4

123.0

62.3

50.8

4.9

15.2

135.0

133.0

Pb*, ppm

206

263.2

236.5

242.4

254.1

224.2

293.3

259.3

247.6

254.3

231.5

229.8

26.0

226.5

245.6

222.1

331.6

228.6

246.0

246.6

264.0

265.0

252.0

223.0

230.0

256.0

259.8

230 261 95 426 – 76

±5.8 ±2.7 ±3.0 ±3.9 ±2.6

238

±1.0

263

327

±1.9

±5.2

176

±1.6

±4.3

347

±2.1

–

193

±0.9

±3.0

211

±1.3

145

119

±7.0

±2.4

279

±15.0

153

242

±15.0

±2.3

229

±14.0

182

115

±13.0

216

142

±13.0

±2.5

234

±1.9

217

±14.0

±237

–

±138

±204

±236

±271

±479

–

±229

±216

±245

±117

±27

±170

±100

±38

±29

±34

±110

±20

±32

±62

±310

±160

±20

±190

207 Pb*/206Pb* Age

±1.5

Pb*/238U Age

206

0.273

0.236

0.292

0.266

0.251

0.326

0.292

0.240

0.272

0.248

0.249

0.286

0.251

0.284

0.240

0.389

0.248

0.270

0.260

0.299

0.296

0.278

0.234

0.245

0.285

0.286

Pb*/235U

207

10.0

19.3

6.3

8.7

10.6

11.9

20.9

13.7

9.8

9.3

10.6

5.1

1.2

7.4

4.3

1.8

1.3

1.6

5.5

5.7

5.8

6.3

15.0

9.0

5.7

8.3

±%

0.0417

0.0374

0.0383

0.0402

0.0354

0.0466

0.0410

0.0392

0.0402

0.0366

0.0363

0.0412

0.0358

0.0388

0.0351

0.0528

0.0361

0.0389

0.0390

0.0419

0.0420

0.0398

0.0351

0.0364

0.0406

0.0411

Pb*/238U

206

0.102

0.088

0.202

0.124

0.250

0.152

0.082

0.088

0.098

0.107

0.105

0.143

0.373

0.104

0.167

0.355

0.322

0.337

0.528

0.989

0.972

0.904

0.400

0.636

0.989

0.071

КК

(continued)

1.0

1.7

1.3

1.1

2.7

1.8

1.7

1.2

1.0

1.0

1.1

0.7

0.5

0.8

0.7

0.6

0.4

0.5

2.9

5.6

5.7

5.7

5.8

5.7

5.6

0.6

±%

284 O. Petrov et al.

0.85

0.07

0.75

0.84

48-30 18.1

48-30 18.2

48-30 10.2

0.01

0.17

0.43

S1-6-1.1

S1-6-1.2

S1-6-2.1

0.02

0.01

0.12

43-27.28 4

43-27.28 5

43-27.28 6

1671

2090

6223

2918

1248

411

424

454

2495

4352

5840

4412

8282

U, ppm

1584

2341

8989

4320

1122

333

203

712

3843

5033

10,549

7272

10,038

Th, ppm

0.98

1.16

1.49

1.53

0.93

0.84

0.49

1.62

1.59

1.19

1.87

1.70

1.25

Th/238U

232

55.5

68.7

208.0

96.6

44.7

13.8

14.4

14.6

1.0

1.0

1.0

1.0

1.0

Pb*, ppm

206

244.2

242.1

245.5

244.0

262.3

247.1

249.4

235.0

222.0

215.6

275.7

255.9

244.7

1.18

1.03

0.11

37-23.27 1

37-23.27 2

37-23.27 3

0.99

1.34

0.45

F233-2 1.1

F233-2 2.1

F233-4 1.1

F-233 Zelenaya Griva

0.09

0.56

37-23.27-2(4)

0.61

37-12 4

37-12 7

0.45

37-12 1

NP-37 Lower Norilsk

771

1372

1225

1013

926

997

356

783

733

1192

3779

2137

1843

6973

2329

2872

1545

581

869

637

2.85

1.80

1.88

7.78

2.41

8.33

2.04

0.82

0.75

0.85

279.0 264.9 259.9

– –

236.3

236.2

238.2

236.8

247.2

253.8

241.9

–

29.7

32.3

11.7

25.3

24.6

41.4

25.4

64.0 – – 258.0

±5.0 ±5.9 ±5.0 ±4.8

±2.8

±4.5

262.7

–

–

248.0

±5.1

±4.2

–

203

±4.9

208.0

281

±4.8

±5.3

261

±5.0

278

±4.8

165

±5.4 ±4.8

278

±5.4

21

±2.7

474

104

±2.6

95

271

±1.6

±5.7

119

±5.6

255

±1.7

±141

–

–

±66

–

–

±220

±67

–

±110

±60

±43

±20

±30

±120

±120

±75

±390

±219

±302

±50

±117

±86

207 Pb*/206Pb* Age

±1.5

Pb*/238U Age

206

NP-37, F-233, MP-26, РУ Lower Norilsk, Zelenaya Griva, Kruglogorsky, Morongo intrusives (n = 20)

0.01

43-27.28 1

TP-43 Dyumptalej

1.03

S1-6 4

S-1 Binyuda

0.57

48-30 5.1

Pbc, %

206

48-30 10.1

Crater

Table 6 (continued)

0.292

0.250

0.265

0.264

0.235

0.236

0.244

0.276

0.251

0.265

0.267

0.274

0.276

0.276

0.283

0.279

0.308

0.245

0.224

0.226

0.311

0.270

0.274

Pb*/235U

207

6.2

25.1

18.7

3.6

11.0

21.0

9.4

3.6

10.0

5.2

3.3

2.7

2.2

2.4

5.7

5.5

4.1

17.0

9.2

12.8

2.2

5.0

3.8

±%

0.0411

0.0420

0.0442

0.0373

0.0373

0.0376

0.0374

0.0391

0.0402

0.0382

0.0386

0.0383

0.0388

0.0386

0.0415

0.0391

0.0395

0.0371

0.0350

0.0340

0.0437

0.0405

0.0387

Pb*/238U

206

0.176

0.069

0.082

0.584

0.194

0.119

0.231

0.583

0.211

0.411

0.616

0.733

0.912

0.835

0.367

0.400

0.561

0.146

0.133

0.095

0.262

0.134

0.169

КК

(continued)

1.1

1.7

1.5

2.1

2.2

2.5

2.2

2.1

2.1

2.1

2.0

2.0

2.0

2.0

2.1

2.2

2.3

2.4

1.2

1.2

0.6

0.7

0.6

±%

Isotope Chronology of Geological Processes 285

0.27

0.49

0.04

1.60

0.46

233-6 3

233-6 4

F233-7 1.1

F233-7 1.2

0.12

0.20

K9 2.1

K9 2.2

4700

3879

6622

2242

878

3414

1709

359

3146

U, ppm

7484

10,876

8903

5980

1173

8765

2510

399

3627

Th, ppm

1.65

2.90

1.39

2.76

1.38

2.65

1.52

1.15

1.19

Th/238U

232

0.08

37-34 _22

2.93

1.44

2.11

48-7 1.1

48-7 2.1

48-7 3.1

48-7 3.2

0.02

37-52 1.2

1419

389

1260

1053

481

1211

195

373

365

3

40

1310

907

299

960

64

185

304

0.01

0.11

1.07

0.89

0.64

0.82

0.34

0.51

0.86

227.0

–

235.3 242.0

– –

400.0

1828.0

1898.0

255.3

–

115.0

243.3 234.9

6.5

252.5

–

12.8

243.0

262.5

12.2

241.0

265.7

–

–

268.1

–

–

244.1

241.0

237.5

266.8 17.0 252.0

±4.8 ±4.8

2404.0 1951.8

±32.0

109.1

±3.3 ±34.0

–

–

–

±4.4

±10.4

±3.7

103.0

260.0

±6.1

–

±5.6

232.8

305.8

244.0

122.2

±5.7

±1.7

±1.7

±1.6

±2.4

–

288.0

±4.9

144.0

±5.2

±8.9

±18

±317

–

–

–

±230

±92

–

±92

±56

±106

±186

–

±30

±120

±130

±145

207 Pb*/206Pb* Age

±2.0

Pb*/238U Age

206

113.0

56.2

11.6

–

Pb*, ppm

206

5.410

7.330

0.254

0.206

0.235

0.206

0.255

0.283

0.229

0.251

0.301

0.268

0.281

0.243

0.273

0.244

0.269

0.285

Pb*/235U

207

2.1

2.3

13.5

29.3

58.8

24.4

10.0

4.6

15.0

4.0

2.5

4.7

8.0

28.1

2.4

5.3

6.1

6.2

±%

0.3279

0.3425

0.0383

0.0372

0.0404

0.0371

0.0385

0.0399

0.0384

0.0358

0.0416

0.0381

0.0421

0.0425

0.0386

0.0381

0.0375

0.0423

Pb*/238U

206

2.0

2.0

1.4

1.9

4.2

1.6

2.6

2.3

2.4

0.8

0.7

0.7

0.9

1.9

2.0

2.0

2.3

0.8

±%

0.970

0.893

0.104

0.065

0.071

0.067

0.253

0.492

0.160

0.186

0.258

0.144

0.115

0.067

0.836

0.387

0.368

0.125

КК

Notes Age—In Ma, taking into account errors in decay constant determination. All errors are ±1 sigma. 206Pbc and 206Pb*—common and radiogenic lead. Isotopic ratios and contents of non-radiogenic Pb are corrected by the measured 204Pb. KK is correlation coefficient between 206Pb/238U and 207Pb/235U isotope ratio detection errors. Errors in calibration of the standard are 0.25–0.64%. Dash—The parameter was not determined

0.15

37-52 1.1

NP-3752 Ergalakh

0.46

2.15

37-34 6

MD-48 Oganer

0.97

Ru-2.5 1

NP-3734 Daldykan

NP-3734, MD-48, NP-3752 Daldykan, Oganer, Ergalakh intrusives (n = 8)

0.48

K9 1.1

MP-2bis Kruglogorsky

0.85

233-6 2

Pbc, %

206

F233-4 17.2

Crater

Table 6 (continued)

286 O. Petrov et al.

Isotope Chronology of Geological Processes

287

2 Rhenium–Osmium Isotope Systematics Methods of Re–Os dating, samples. Dissolution of samples and chemical separation of Re and Os were performed in CIR VSEGEI laboratories according to the method [5]. Samples weighing 50–200 mg were digested in a mixture of reagents (1 ml of Br2 + 2 ml of 7 N HNO3 + 0.5 ml of 40% CrO3 in 7 N HNO3) in 5 ml Teflon Seville vials at 90 °C for 48 h. Then, osmium was separated by microdistillation, and rhenium, by liquid extraction with isoamyl alcohol. To determine Re and Os concentration and 87Re/188Os ratio, isotope dilution with mixed tracer 85 Re–190Os was used. Isotopic composition of osmium was measured by solid phase multi-collector mass spectrometer TIMS Triton TI (Thermo Scientific) in a static mode in negatively charged ions on Faraday collectors. Os in the form of bromide was applied to platinum band of evaporator. To improve ionization efficiency, device puffing oxygen in the mass spectrometer chamber was used. For correction for mass fractionation, 192Os16O3/188Os16O3 = 3.092016 ratio was used. Measurement of isotopic composition and determining Re concentration from solution were made on a single-collector inductively coupled plasma mass spectrometer ICP-MS ELEMENT2 (Thermo Scientific). One of the most effective indicators of commercial-scale mineralization is the initial isotopic composition of osmium. This is primarily due to the fact that massive ore from commercial deposits, according to Walker et al. [18], is characterized by values corresponding to a mixture of crustal and mantle material with the largest share of mantle component. In the disseminated ores of the same deposits mantle component is strongly “diluted” with crustal one, as disseminated ore is more “sensitive” to contamination by crustal material in comparison with massive ores. It was also found that the proportion of mantle component is minimal in weakly mineralized Lower Talnakh and Lower Norilsk intrusions [18], in which the low mass of sulphide material was, probably, least protected from crustal contamination. We have characterized not only ore from commercially mineralized (Talnakh and Kharayelakh) and weakly mineralized (Lower Talnakh, Lower Norilsk, and Zelenaya Griva) intrusions, but also disseminated ore from reserve deposits of mineralized intrusions (Chernogorsky, Zub-Marksheidersky, South Pyasino, and Vologochan) in the Norilsk Province and occurrences of potentially mineralized Binyuda intrusion in the Taimyr Province. A total of 31 sulphide ore samples from commercially mineralized Talnakh and Kharaelakh intrusions have been studied; 12 samples from mineralized Chernogorsky, Zub-Marksheidersky, South Pyasino, and Vologochan intrusions; two samples from potentially mineralized Binyuda intrusion, and 12 samples from weakly mineralized Lower Talnakh, Lower Norilsk, and Zelenaya Griva intrusions. Results of Re–Os investigations. Isotope-geochemical characteristics of commercially mineralized intrusions. Talnakh intrusion, disseminated and massive sulphide ores. Re–Os method was used to analyse a series of disseminated and massive ore samples from OUG-2 drill core. Re–Os isochrone with age of 247 ± 18 Ma and initial osmium ratio of 187Os/188Os = 0.1366 ± 0.0037 was

288

O. Petrov et al.

Fig. 4 Re–Os isochrons after disseminated (1) and massive (2) sulphide ores of Talnakh intrusive

obtained from massive ore samples; isochrone corresponding to the age of 245 ± 27 Ma and initial isotopic composition of 187Os/188Os = 0.1350 ± 0.0036 was constructed from disseminated ore samples (Fig. 4). Since age and initial Os/ Os ratio in both ore types are similar, their analytical data can be combined into a single isochrone corresponding to the age of 251 ± 13 Ma (187Os/188Os = 0.1348 ± 0.0021, mean square weighted deviation (MSWD) = 125). Significant isochron MSWD are due to variations in initial isotopic composition of sulphides from various horizons in sequence. Age data coincide with the results by Walker et al. obtained earlier [18], which cite a combined Re–Os isochron with age of 245.7 ± 0.6 Ma and initial ratio of 187Os/188Os = 0.1326 ± 0.0025, received from sulphides of Norilsk-1 and Talnakh intrusions. According to our data, disseminated ores have lower initial osmium ratio (187Os/188Os = 0.1350) compared to massive ores (187Os/188Os = 0.1366), that may be both due to a lower degree of osmium contamination from host rocks by disseminated ores and by slightly earlier crystallization of disseminated ores compared with massive ores. Model initial osmium ratio computed for the age of 250 Ma (osmium gamma, cOs) for disseminated ore is also lower than that of massive ore (5.7–7.4 vs. 7.5–8.8). Model ages for both ore types overlap: 270– 320 Ma for massive and 292–333 Ma for disseminated. Re/Os ratio in massive ore samples (1.3–4.2) varies over a wider range than in disseminated ore samples (1.0–2.4). Rhenium and osmium concentrations, as well as the range of fluctuations in massive ore are larger than in disseminated ones. Kharaelakh intrusion, disseminated and massive sulphide ores. Re–Os method was used to analyse a series of disseminated and massive ore samples from KZ-844

Isotope Chronology of Geological Processes

289

Fig. 5 Re–Os isochron after massive sulphide ores of Kharaelakh intrusive

and KZ-963 drill core. Re–Os isochron with age of 246.8 ± 3.7 Ma and initial osmium ratio of 187Os/188Os = 0.1283 ± 0.0054 was obtained from massive ore samples (Fig. 5). At the same time, the analysed disseminated ore samples are characterized by a series of parallel isochrones with similar ages but different initial osmium ratios (Fig. 6). The main analysis sampling forms an isochron corresponding to the age of 247 ± 21 Ma and initial isotopic composition of 187Os/188Os = 0.1331 ± 0.0052. Furthermore, two of the remaining four analyses form an isochron with age of 248.7 ± 2.9 Ma and higher 187Os/188Os = 0.13642, while two analyses lie on the isochron with age of 249.6 ± 2.2 Ma and even higher 187 Os/188Os = 0.14356 (Fig. 6). These age data on the majority of disseminated ore samples are consistent with the Re–Os results by Walker et al. [18], giving a Re–Os isochron for the Kharayelakh intrusion sulphides with age of 247.0 ± 3.8 Ma and initial ratio of 187 Os/188Os = 0.133 ± 0.021. According to our data, massive sulphide ores have significantly lower initial osmium ratio (187Os/188Os = 0.1283) in comparison with disseminated ores (187Os/188Os = 0.1331), that may be both due to a lower degree of osmium contamination from host rocks by massive ore and a more primitive nature of massive sulphide ore source. Moreover, heterogeneity of the initial osmium isotope ratio 187 Os/188Os (from 0.1331 to 0.1436) with coinciding within the limits of age error is observed in disseminated ores. Revealed heterogeneity may also be associated with mixing and contamination in the magma chamber. Model initial osmium ratio

290

O. Petrov et al.

Fig. 6 Re–Os isochron after disseminated sulphide ores of Kharaelakh intrusive

computed for the age of 250 Ma for disseminated ores is from 4–6 to 13–14. Re/Os ratio in massive ore samples (1.4–47.8) varies in a much greater range than in disseminated ore samples (1.6–8.8) due to reduced osmium content in massive ores (1–15 vs. 30–55 ppm). Rhenium concentration in disseminated ores is also higher than in massive ores. Model age of massive ores varies in a considerably wider range than the model age of disseminated ores (227–322 and 256–303 Ma). Re–Os isotope-geochemical characteristics of potentially mineralized intrusions. Chernogorsky intrusion, disseminated ores. Re–Os method was used to analyse two samples of disseminated sulphide ores from MP-2 bis drill core. Along with disseminated ore samples from Zub-Marksheidersky, South Pyasino, and Vologochan intrusions with off-balance ores, samples from the Chernogorsky intrusion form a Re–Os isochron with age of 248 ± 14 Ma and initial osmium ratio of 187Os/188Os = 0.1381 ± 0.0014 (Fig. 7). Disseminated ore from the Chernogorsky intrusion is characterized by high Re (155–170 ppm) and Os (230–305 ppm), low Re/Os ratio (0.6–0.7), arelatively older model age (418–457 Ma) and moderate osmium gamma values (9.5–9.6). Zub-Marksheidersky intrusion, disseminated ores. Re–Os method was used to analyse two disseminated sulphide ore samples from MP-27 drill core. One of Zub-Marksheidersky samples, along with samples from other mineralized intrusions (Chernogorsky, South Pyasino, and Vologochan), participates in the construction of Re–Os isochron with age of 248 ± 14 Ma and initial osmium ratio 0.1381 ± 0.0014 (Fig. 7). Disseminated ore from the Zub-Marksheidersky intrusion is characterized by average Re (185–275 ppm) and Os (53–142 ppm) contents, average Re/Os ratio

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Fig. 7 Re–Os isochron after disseminated ores of ore-bearing intrusives in Norilsk Province

(1.9–3.5), relatively increased model age (310–377 Ma), and moderate to high osmium gamma values (9.7 and 31.6). One of the samples (corresponding to disseminated ores from an extremely altered olivine gabbro from the lower intrusion) shows signs of rhenium loss in the Re–Os isochron diagram, being much left of the isochron (Fig. 7). South Pyasino intrusion, disseminated ores. Re–Os method was used to analyse five samples of disseminated sulphide ore from OM-25 drill core (Table 8 in Chapter “Strontium and Neodymium Isotopes”). Along with samples from other mineralized intrusions (Chernogorsky, Zub-Marksheidersky, and Vologochan), samples from the South Pyasino intrusion form Re–Os isochrons with age of 248 ± 14 Ma with (187Os/188Osi) = 0.1381 ± 0.0014 and 250 ± 86 Ma with (187Os/188Osi) = 0.131 ± 0.014 (Fig. 7). Disseminated ore from the South Pyasino intrusion is characterized by average Re (49–207 ppm) and Os (24–168 ppm) contents, average Re/Os ratio (1.0–2.2), average model age (262–343 Ma), moderate osmium gamma values (3.7–10.1), and bimodal nature of the initial osmium ratio (0.131 and 0.138). Vologochan intrusion, disseminated ores. Re–Os method was used to analyse three disseminated sulphide ore samples from OB-29 drill core. Along with samples from other mineralized intrusions, samples from Vologochan intrusion form Re–Os isochrons with age of 248 ± 14 Ma, where (187Os/188Osi) = 0.1381 ± 0.0014 and 250 ± 86 Ma with (187Os/188Osi) = 0.131 ± 0.014 (Fig. 7). Disseminated ore is characterized by average Re (194–262 ppm) and Os (74– 115 ppm) contents, average Re/Os ratio (1.9–2.6), average model ages (265– 295 Ma), and moderate osmium gamma values (4.3–9.9). Like ores from the South Pyasino intrusion, disseminated ores from the Vologochan intrusion exhibit bimodal initial osmium ratio (0.131 and 0.138).

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Fig. 8 Re–Os isochron after sulphide ores of ore-bearing intrusives in Norilsk Province and potentially ore-bearing Binyuda intrusive in Taimyr Province

Binyuda intrusion, vein ore. Re–Os method was used to analyse two vein sulphide ore samples from C-2 drill core (Table 8 in Chapter “Strontium and Neodymium Isotopes”). Along with mineralized intrusion samples (Chernogorsky, Zub-Marksheidersky, South Pyasino, and Vologochan) with off-balance ores, veinlet ore samples from the Binyuda intrusion correspond to previously given Re–Os isochron (Fig. 7), and are characterized by age of 251 ± 13 Ma and initial osmium ratio of 187Os/188Os = 0.1375 ± 0.0011 (Fig. 8). Similarity in age and initial osmium ratio, despite the fact that this intrusion is significantly distant from the remaining massifs, indicates osmium source similarity between these two regions. Binyuda intrusion ore is characterized by average Re (22–264 ppm) and increased Os (256–1437 ppm) contents, very low Re/Os ratio (0.09–0.18), ancient model ages (750–1566 Ma), and moderate osmium gamma values (8.1–9.5). Isotope-geochemical characteristics of weakly mineralized intrusions. Lower Talnakh intrusion, disseminated ores. Re–Os method was used to analyse five sulphide ore samples from TG-31 drill core. Disseminated ore from the Lower Talnakh intrusion forms Re–Os isochron with age of 247 ± 45 Ma and (187Os/188Osi) = 0.197 ± 0.095 (Fig. 9). Disseminated ore has increased Re (119–316 ppb) and low Os (4.4–20.6 ppb) content, high Re/Os ratio (13.7–71.6), average model ages (261–318 Ma), and high osmium gamma values (35.6–117.8), consistent with the data by Arndt et al. [3] (cOs = 46–71). Lower Norilsk intrusion, disseminated ores. Re–Os method was used to analyse 6 sulphide ore samples from NP-37 drill core. Disseminated ore from the Lower Norilsk intrusion is characterized by Re–Os isochron with age of 251 ± 30 Ma and (187Os/188Osi) = 0.196 ± 0.033 (Fig. 10).

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Fig. 9 Re–Os isochron after disseminated ores of Lower Talnakh intrusive

Fig. 10 Re–Os isochron after disseminated ores of Lower Norilsk intrusive

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Disseminated ore has increased Re (119–203 ppm) and low Os (7.0–28.3 ppm) content, high Re/Os ratio (6.5–17.1), average model ages (289–361 Ma), and high osmium gamma values (47.7–61.2), which are close to the data by Arndt et al. [3] (cOs = 10.2–67.4). If we exclude the extreme upper and lower points from isochrons in Fig. 10, we obtain the age of 251 ± 20 Ma. Zelenaya Griva intrusion, disseminated ores. Re–Os method was used to analyse one disseminated sulphide ore sample from NP-37 drill core. Disseminated ore from the Lower Norilsk, Lower Talnakh, and Zelenaya Griva intrusions form a Re– Os isochron with age of 250 ± 14 Ma (187Os/188Osi) = 0.195 ± 0.013 (Fig. 11). Disseminated ore from the Zelenaya Griva intrusion is characterized by increased Re (255 ppm) and average Os (33 ppm) content, high Re/Os ratio (7.8), average model age (352 Ma), and high osmium gamma values (54.5). We have obtained new Re–Os age and isotope-geochemical data for the Talnakh and Kharayelakh intrusions separately for massive and disseminated ores. Age data coincide within the age determination error with the data by Walker et al. [18]. Initial isotope ratios are somewhat different from those in the literature; differentiation of ore types has been revealed. Additional Re–Os results are also obtained for the Lower Talnakh and Lower Norilsk intrusions compared with data by Arndt et al. [3], which made it possible to calculate the Re–Os isochrone age for weakly mineralised intrusions. Re–Os data for the Chernogorsky, Zub-Marksheidersky, Vologochan, South Pyasino, and Zelenaya Griva intrusions have been first obtained. Initial Re–Os isotopic data for rocks and ores are given in Tables 7, 8, 9 and 10.

Fig. 11 Re–Os isochron after disseminated ores of Lower Talnakh (1), Lower Karelia (2) and Zelenaya Griva (3) weakly ore-bearing intrusions

Test portion, g

Disseminated ores T-13 0.04273 T-19 (duplicate of 0.05720 T-14) T-15 0.01514 T-16 0.04658 T-17 0.05481 T-18 0.04797 Massive ores 87sr (chalcopyrite) 0.06923 87s 0.07799 79s 0.07414 96s 0.09219 Note cOs value is calculated for the age of

Sample number

20.53 9.89 7.11 6.41

188.9 45.1 4.2 221.3 109.1 2.0 369.3 252.9 1.5 366.9 278.5 1.3 250 Ma. Model age in Ma

5.01 4.76

Re/188Os

187

8.57 7.59 8.43 11.75

89.3 109.3 108.2 88.1

157.1 171.3 188.2 213.3

1.0 1.0

Re/Os

1.8 1.6 1.7 2.4

185.4 141.3

Os, ppm

192.2 139.0

Re, ppm

0.5 0.5 0.5 0.5

0.5 0.5 0.5 0.5

0.5 0.5

±%, 2r

0.22113 0.17742 0.16667 0.16225

0.17086 0.16607 0.16975 0.18237

0.15412 0.15510

Os/188Os

187

0.00022 0.00007 0.00013 0.00018

0.00009 0.00075 0.00057 0.00017

0.00016 0.00019

±, 2r

Table 7 Re-Os isotopic characteristic of disseminated and massive sulphide ores of Talnakh intrusive (Bh. OUG-2), n = 10

269.9 295.4 320.3 313.8

295.1 295.4 292.1 273.8

304.4 333.1

Model age

7.5 8.1 8.8 7.6

7.3 6.7 6.8 5.8

5.7 7.4

cOs

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Disseminated ores T-13 T-19 (duplicate of T-14) T-15 T-16 T-17 T-18 Massive ores 87 sr (chalcopyrite) 87s 79 s 96 s Note cOs was calculated

Sample number

157.1 171.3 188.2 213.3

0.01514 0.04658 0.05481 0.04797

89.3 109.3 108.2 88.1

185.4 141.3

Os, ppm

0.06923 188.9 45.1 0.07799 221.3 109.1 0.07414 369.3 252.9 0.09219 366.9 278.5 for the age 250 Ma. Model age in Ma

192.2 139.0

Re, ppm

0.04273 0.05720

Test portion, g

4.2 2.0 1.5 1.3

1.8 1.6 1.7 2.4

1.0 1.0

Re/Os

20.53 9.89 7.11 6.41

8.57 7.59 8.43 11.75

5.01 4.76

Re/188Os

187

0.5 0.5 0.5 0.5

0.5 0.5 0.5 0.5

0.5 0.5

±%, 2r

0.22113 0.17742 0.16667 0.16225

0.17086 0.16607 0.16975 0.18237

0.15412 0.15510

Os/188Os

187

0.00022 0.00007 0.00013 0.00018

0.00009 0.00075 0.00057 0.00017

0.00016 0.00019

±, 2r

Table 8 Re–Os isotopic characteristics of disseminated and massive sulphide ores of Talnakh intrusive (Bh. OUG-2), n = 10

269.9 295.4 320.3 313.8

295.1 295.4 292.1 273.8

304.4 333.1

Model age

7.5 8.1 8.8 7.6

7.3 6.7 6.8 5.8

5.7 7.4

cOs

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Test portion, g

Chernogorsk, Bh. MP-2bis CH-11 0.05991 CH-13 0.01485 Zub-Marksheidersky, Bh. MP-27 27-13, 87.2 m 0.05126 MP-27/96.9 m 0.13771 South Pyasina, Bh. OV-25 25-20 0.07222 25-31 0.09783 25-35 0.10404 25-36 0.07782 25-41 0.0559 Vologochan, Bh. OV-29 OV-29/852.3 0.08436 29-24 (854–855) 0.09490 OV-29/867.5 0.12113 Binyuda, Bh. S-2 S-2/1 0.08512 S-2/2 0.11355 See note to Table 7

Intrusive, sample number 305.5 230.1 143.0 52.6 168.4 99.9 59.5 95.6 24.4 74.4 111.2 115.1 256.7 1437.2

275.3 185.8 166.9 150.1 97.4 207.5 49.1 194.8 207.6 262.4 22.2 264.4

Os, ppm

169.7 155.3

Re, ppm

0.1 0.2

2.6 1.9 2.3

1.0 1.5 1.6 2.2 2.0

1.9 3.5

0.6 0.7

Re/Os

0.42 0.89

12.79 9.10 11.12

4.82 7.32 7.97 10.59 9.82

9.39 17.36

2.70 3.28

Re/188Os

187

0.5 0.5

0.5 0.5 0.5

0.5 0.5 0.5 0.5 0.5

0.5 0.5

0.5 0.5

±%, 2r

0.13973 0.13986

0.19182 0.16935 0.17791

0.15631 0.16926 0.16540 0.18013 0.17160

0.17737 0.23823

0.14927 0.15160

Os/188Os

187

0.00014 0.00014

0.00014 0.00015 0.00011

0.00035 0.00028 0.00055 0.00011 0.00011

0.00013 0.00036

0.00008 0.00071

±, 2r

1566.9 750.5

295.8 268.1 265.4

343.8 332.0 276.4 291.3 262.2

310.8 377.8

457.4 418.8

Model age

9.5 8.1

9.9 4.3 4.4

8.1 10.1 4.9 7.9 3.7

9.7 31.6

9.6 9.5

cOs

Table 9 Re–Os isotopic characteristics of disseminated sulphide ores of Chernogorsk (boreholes MP-2bis, Ch-11, Ch-13), Zub-Marksheidersky (Bh. MP-27), South Pyasina (Bh. OV-25), Vologochan (Bh. OV-29) and Binyuda (Bh. C-2) intrusives, n = 14

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Lower Talnakh, Bh. TG-31 31 3 31-_3 (duplicate) 31-10 31-11 31-11 (duplicate) Lower Norilsk, Bh. NP-37 37-9g 37-11a 37-12a 37-12b 37-12v 37-12g Zelenaya Griva, Bh. F-233 F-233-10 See note to Table 7

Intrusive, sample number 281.2 316.2 196.5 119.4 250.9 184.4 166.0 191.8 119.3 203.4 191.3 255.1

0.06144 0.06969 0.14567 0.09187 0.06896 0.16664

0.05475

Re, ppm

0.05422 0.09788 0.08567 0.00888 0.04216

Test portion, g

32.9

28.3 12.5 19.0 7.0 13.3 15.7

20.6 4.4 5.4 5.7 6.1

Os, ppm

7.8

6.5 13.3 10.1 17.1 15.3 12.2

13.7 71.6 36.6 21.0 41.2

Re/Os

38.73

32.42 67.54 50.72 87.17 78.00 61.43

68.94 432.61 199.80 108.20 225.39

Re/188Os

187

0.5

0.5 0.5 0.5 0.5 0.5 0.5

0.5 0.5 0.5 0.5 0.5

±%, 2r

0.35628

0.32423 0.48133 0.41226 0.54982 0.52682 0.45941

0.49512 2.01893 1.10827 0.62474 1.11154

Os/188Os

187

0.00039

0.00027 0.00086 0.00029 0.00061 0.00058 0.00108

0.00149 0.00102 0.00115 0.00044 0.00121

±, 2r

351.7

361.1 312.6 334.7 289.3 305.7 322.3

318.2 261.7 293.6 274.6 261.2

Model age

54.5

50.0 58.3 59.2 47.7 59.8 61.2

64.6 69.4 117.8 37.5 35.6

cOs

Table 10 Re–Os isotopic characteristics of disseminated sulphide ores of Lower Talnakh (Bh. TG-31), Lower Norilsk (Bh. NP-37) and Zelenaya Griva (Bh. F-233) intrusives, n = 12

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3 Results and Discussion Injection time of three main mineralized intrusions in the Norilsk district is practically the same. Natural reference points limiting the injection event are reliable ages of felsic volcanics (rhyodacites)—270 ± 3 Ma, U–Pb, zircon, SIMS SHRIMP-RG (lower limit) and the age of conjugate mafic trap lava flows— 249 ± 2 Ma, Ar–Ar (upper limit). Formation of magmatic zircon generations in each of the studied intrusions in the area reflects the crystallization time of silicate portion of the geological objects. Two consecutive episodes (pulses) of injection and crystallization of silicate melt can be distinguished on the basis of the data obtained: early, 254 ± 4 Ma, and later, 244 ± 4 Ma. The total duration of magmatic activity of this type is about 10 million years. Sulphide matrix (mineralization process) is almost synchronous to the silicate one; its age is 245–250 Ma according to Re–Os ID-TIMS method. Powerful secondary alteration processes with preferential removal of Th and active migration of U and REE developed at about 220–230 (225 ± 5) Ma. Against the background of active recrystallization (both partial and complete) of the matrix of primary magmatic generations, proper metasomatic generation of zircons was formed, confined to the expressed zones of metasomatic reworking of rocks within intrusions. Age of the secondary (alteration) processes manifested in all intrusions is the same (220–230 Ma) and exactly matches the time of plagiogranite massif injection into the Norilsk district rocks during tectonic and magmatic activity, for example, Bolgotokh, 229.0 ± 0.4 Ma (U–Pb, zircon) and universal biotite development with age of 225–230 Ma (40Ar/39Ar). Age values in the range of 260–270 Ma are overstated and reflect redistribution and migration of excess uranium. U–Pb system of such zircons is often characterized by reverse discordance. The presence of inherited zircon microdomains playing a role of seed cores during crystallization is also possible. There is a clear trend towards an increase in the number and variety of inherited zircons from the Kharaelakh (maximum) to the Talnakh (minimum) intrusion. The inherited Variscan zircons (P-C) are clearly distinguished by a significantly lower uranium content. Large number of xenogenic Permian and Carboniferous (290, 300, 330, and 350 Ma) zircons in mafic rocks of the Norilsk district intrusions have been revealed. No Devonian (360–420 Ma) zircons have been found. These zircons reflect the age and composition of crustal rocks hosting intrusions, formations, from which they are trapped during injection as well as indicate their degree of assimilation. Individual Proterozoic and Archean zircon grains aged at 1.9 and 2.7 Ga (in the Norilsk and Pyasino-Vologochan intrusions) have been detected; this indicates the presence of ancient basement in the Norilsk district.

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Mafic igneous rocks formed at the turn of the Jurassic and Cretaceous, 145– 150 Ma, are first identified. Their genetic relationship with the complex of the Norilsk mineralized intrusions is not determined.

4 Geochronology Isotope Mineralization Criterion and Metallogenic Consequences Silicate matrix of intrusions in both pulses (especially the early one), along with other lithophylic elements is enriched in uranium, whose significant amounts may be localized in intrusion areals, which was reflected in extremely high concentrations of this element in primary magmatic zircons (thousand ppm at a standard of hundred ppm) and high (>2) Th–U ratio. This indicates a high probability of the presence of uranium mineralization in the spatial and genetic association with mafic intrusions. Search and study of xenogenic zircons is no less important than dating of igneous populations. Also of interest is the study of detrital zircons from the host sedimentary rocks and directly from sulphide ores. Xenogenic zircons reflect the age and composition of crustal rocks, from which they are trapped during intrusion injection, and their number also indicates the degree of rock assimilation. In our opinion, it requires a special comparative study of xenogenic zircon population in various intrusions and ores with a view to identifying the direct connection between PGE-sulphide mineralization and a specific horizon of assimilated Paleozoic and/or Precambrian host rocks. Such rocks can claim as an additional source of mobilized and redeposited useful component (lateritic crust, paleo-placers etc.). Productive intrusions belong to the earlygroup; their injection initiated migration and accumulation of components (PGE, sulphur, uranium). The most promising intrusions in the Norilsk district: – magmatic generation of accessory zircons is no younger than 250–255 Ma, i.e. when crystallization of silicate part slightly preceded the formation of sulphide (ore) part (Re–Os isochron method); – maximum component of xenogenic (captured during injection) Paleozoic zircons, indicating a substantial assimilation of host rock substance of this age, is revealed. Secondary Late Triassic (225–230 Ma) alterations do not have a negative impact on commercially valuable sulphide ore stocks. The absence of large amounts of sulphide ores in the late group intrusions (240– 247 Ma), even in the presence of similar to the early group intrusions evidence of the Paleozoic rock assimilation (zircon xenocryst), points to the injection of the late group intrusions into enclosing rocks already depleted in ore-forming components.

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It is surprising, that the relationship between hafnium isotopic composition and ore content is preserved for zircons, which are 20 million years younger than the ore material. Obviously, the isotopic characteristics of silicate material that is not related to mineralization may not reflect the extent of ore content. Direct age determination of sulphide ores by Re–Os isochron method allows us to understand the geological interpretation of U–Pb data in zircons. Re–Os data with a surprising constancy match age of about 250 Ma for all the studied intrusions. This correspondence reflects a high degree of almost synchronous sulphide Cu–Ni ore formation with the time of magmatism (injection and crystallization of silicate intrusion melt), leaving no grounds for assumptions about the ore system development for tens or hundreds of millions years prior to this stage. The secondstage dated by zircon at 230 Ma is not associated with sulphide ore formation and reflects the age of the imposed process. Its geological essence requires further study, but is most likely to be identified with Co–Ni–Sb–As vein mineralization of essentially another type manifested in the same massifs. Thus, commercially mineralized intrusions of Norilsk-1, Talnakh, and Kharaelakh formed in the Norilsk ore district at the early magmatism stage at 254 ± 4 Ma, likely due to a deep mantle plume source. Abundance of fluid phase and a high mole fraction of water in the fluid, on the one hand, led to the formation of horizons with low-sulphide Pt–Pd mineralization, on the other hand, a high capacity for assimilation of crustal material, which contributed to the formation of massive sulphide ores. Multiple isotope systematics of radiogenic Sr, Nd, Hf, and Pb isotopes indicates that the crustal material was intensely drawn into rock and ore formation in the Norilsk ore district. Later stage of deep magmatism at 244 ± 4 Ma in the traditional isotopic and geochemical classification of mantle material was accompanied by active participation of depleted mantle source, resulting both in a smaller number of exceptionally disseminated Cu-Ni sulphide ores and, probably, in the lack of economically valuable platinum group metal deposits.

References 1. Lyakhnitskaya IV, Tuganova EV (1977) Regional and local patterns of copper-nickel sulphide deposits distribution. L.: Nedra, 77 p 2. Malich NS, Masaitis VL, Staritsky Yu G (1974) Geologic formations of the pre-cenozoic cover of the Siberian platform and its mineralization. M.: Nedra, 280 p 3. Arndt NT, Czamanske G, Walker RJ et al (2003) Geochemistry and origin of the intrusive hosts of the Noril’sk-Talnakh Cu-Ni-PGE sulphide deposits. Econ Geol 98:495–515 4. Black LP, Kamo SL, Allen CM et al (2003) TEMORA 1: a new zircon standard for U–Pb geochronology. Chem Geol 200:155–170 5. Birck JL, Barman MR, Campas F (1997) Re–Os isotopic measurements at the femtomole level in natural samples. Geostandards Lett 20(1):19–27 6. Campbell IH, Czamanske GK, Fedorenko VA et al (1992) Synchronism of the Siberian traps and the Permian-Triassic boundary. Science 258:1760–1763

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7. Czamanske GK, Gurevitch AB, Fedorenko V, Simonov O (1998) Demise of the Siberian plume: Paleogeographic and paleotectonic reconstruction from the prevolcanic and volcanic record, north-central Siberia. Int Geol Rev 41:95–115 8. Czamanske GK, Wooden JL, Walker RJ et al (2000) Geochemical, isotopic, and SHRIMP age data for Precambrian basement rocks, Permian volcanic rocks, and sedimentary host rocks to the ore-bearing intrusions, Noril’sk-Talnakh district, Siberian Russia. Int Geol Rev 42: 895–927 9. Dalrymple GB, Czamanske GK, Fedorenko A et al (1995) Areconnaissance 40Ar/39Ar geochronological study of ore-bearing and related rocks, Siberian Russia. Geochim Cosmochim Acta 59:2071–2083 10. Dalrymple GB, Czamanske GK, Lanphere MA et al (1991) 40Ar/39Ar ages from samples from the Noril’sk-Talnakh ore bearing intrusions and the Siberian flood basalts, Siberia. EOS 72:570 11. Kamo SL, Czamanske GK, Krogh TE (1996) Aminimum U–Pb age for Siberian flood-basalt volcanism. Geochim et Cosmochim Acta 60:3505–3511 12. Kamo SL, Czamanske GK, Amelin Y et al (2003) Rapid eruption of Siberian flood-volcanic rocks and evidence for coincidence with the Permian-Triassic boundary. Earth Planet Sci Lett 214:75–91 13. Ludwig KR (2001) SQUID 1.02, A User Manual, A geochronological toolkit for microsoft excel. Berkeley Geochronology Center Special Publication, Berkeley, USA 14. Ludwig KR (2003) User’sManual for Isoplot/Ex, Version 3.00, AGeochronological Toolkit for Microsoft Excel. Berkeley Geochron. Center Spec. Publ. Berkeley, USA 15. Renne PR (1995) Excess 40Ar in biotite and hornblende from the Norilsk I intrusion, Siberia: implications for the age of the Siberian Traps. Earth Planet Sci Lett 131:165–176 16. Schuth S, Gornyy VI, Berndt J et al (2012) Early proterozoic U–Pb zircon ages from Basement Gneiss at the Solovetsky Archipelago, White Sea, Russia. Int J Geosci 3(2): 289–296 17. Stacey S, Kramers JD (1975) Approximation of terrestrial lead isotope evolution by a two-stage model. Earth and Planet Sci Lett 26:207–221 18. Walker RJ, Morgan JW, Horan MF et al (1994) Re–Os isotopic evidence for an enriched mantle source for the Noril’sk-type ore-bearing intrusions, Siberia. Geochim et Cosmochim Acta 58:4179–4197 19. Wetherill GW (1956) Discordant uranium-lead ages. Trans Amer Geophys Union 37:320–326 20. Wiedenbeck M, Allé P, Corfu F et al (1995) Three natural zircon standards for U–Th–Pb, Lu–Hf, trace element and REE analyses. Geostand Newslett 19:1–23 21. Williams IS (1998) U–Th–Pb geochronology by ion microprobe. In: McKibben MA, Shanks III WC, Ridley WI (eds) Applications of microanalytical techniques to understanding mineralizing processes. Rev Econ Geol 7:1–35 22. Wooden JL, Czamanske GK, Fedorenko VA et al (1993) Isotopic and trace-element constraints on mantle and crustal contributions to characterization of the Siberian continental flood basalts, Norilsk area, Siberia. Geochim Cosmochim Acta 57:3677–3704

Conclusion

Sources of rock and ore substance. Complex isotopic criterion for mineralization of mafic intrusions in the Norilsk District. Integrated isotopic studies of the Norilsk-Taimyr district intrusions held at CIR VSEGEI allowed us to clarify and specify a number of questions on the origin of rock and ore substance, formation of Cu-Ni-PGE-deposits. Particular attention was paid to the diagnosis of substance sources by isotopic genetic markers, as well as rock and ore age determination, duration of geological processes using isotopic techniques. In addition, the isotopic criteria for mineralization scale of ultramafic intrusions were sought. Almost all isotopic indicators pointed at an extended participation of crustal material in the ore genesis. For example, the composition of helium, an effective indicator of fluid “mantle nature”, incorporates a very high proportion of the Earth’s crust helium. Paleofluids from rocks and ores are dominated by helium with a low 3 He/4He isotope ratio, formed only in the Earth’s crust rocks. In commercially mineralized (rich) intrusions, the share of mantle helium does not exceed 4%. Low-ore intrusions contain much more mantle helium, to 22%. Ore mineral sulphur in rich intrusions is only crustal. Its isotopic composition (d34S) is very different from that in most cases and similar to that observed in anhydrite of enclosing sedimentary rocks. In accordance with the pronounced correlation links in the isotopic composition of sulphur, helium, and argon, in rich intrusions one can assume the presence of two crustal sources. The temperature of ore mineral formation is estimated by sulphur isotopic geothermometers at a few hundred degrees. Set of data on the isotopic composition of strontium and neodymium clearly indicates a significant influence of the crustal component on the injected mantle fluid. Computation of crust and mantle contribution in this two-component system, unfortunately, is impossible due to an uncertain knowledge of crustal isotopic coordinates. Features of the isotopic composition of lead, lutetium–hafnium system elements also indicate an intense crust–mantle interaction. Apparently, zircon source rocks with high Lu/Hf and Yb/Hf also had high values of these ratios. It is assumed that © Springer Nature Switzerland AG 2019 O. Petrov (ed.), Isotope Geology of the Norilsk Deposits, Springer Geology, https://doi.org/10.1007/978-3-030-05216-4

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these formations were phosphate-bearing, clayey and evaporite rocks providing fluids with halogens. These rocks are adequately presented in the sequence of enclosing sedimentary beds. It can be reasonably assumed that the contribution of crustal material is great, especially in ores, and that this substance is not only a passive content, but may provoke ore genesis. Not less important information has been revealed about the other isotopes of another noble gas, argon, an indicator of underground fluid communication with the atmosphere. Mafic rocks of Norilsk, especially ores, are dominated by argon of atmospheric origin, which indicates an extremely high contribution of subsurface water from rocks enclosing intrusions into mineralizing fluid formation. A particularly high proportion of atmospheric argon (88–100%) is in rich intrusions. It is typical of gas from shallow sedimentary strata (1–2 km). Apparently, ore deposition was accompanied/caused by intense water circulation in sedimentary strata, penetrating into the zone of intrusion crystallization. Circulation was obviously initiated by magma injection into the sedimentary layers. Water streams could carry ore components and deposit them at the postmagmatic stage. In case of sufficient mineral wealth and water volume involved in this process, one may be able to solve the problem of copper balance in deposits and source rocks. Clear correlation of helium and argon isotope ratios in three richest intrusions has been revealed; the presence of, at least, two different fluid sources is admitted. Copper and lead isotopes of ore minerals from these intrusions also exhibit a correlation with the composition of noble gases and sulphur. Apparently, these metals from sulphides also owe their origin to the sources mentioned above. Nickel isotopic composition variations are not related to those in noble gases, copper, lead, and sulphur. The immediate source of nickel is, probably, mantle protoliths of mafic rocks. Isotope systematics indicates that ore formation is directly related to the assimilation by mantle magmas of enclosing sedimentary rock substance (including fluids). This follows from the isotopic characteristics of noble gases, sulphur and copper, neodymium, strontium, and hafnium. It is hoped that the “isotopic” arguments will be used in the construction and testing of deposit formation models for the Norilsk district. Academician A.P. Vinogradov, an enthusiast and organizer of isotope geochemical studies in our country, called for developing this very approach to grading of existing models and choice of the most appropriate ones. Age limits for formation of intrusions differing in mineralization scale, as well as of sulphide ores themselves have been established. We received a large amount of data about the time of geological processes on the basis of uranium-lead local dating of accessory zircons from a wide variety of rocks. Magmatic generation of accessory zircons is aged at 250–255 Ma. This means that crystallization of the silicate part of material slightly preceded the formation of the sulphide (ore) part (245–250 Ma). The presence in rocks of productive intrusions of xenogenic (captured during injection) Paleozoic, Proterozoic, and Archean zircons is also important. This, in turn, suggests a substantial assimilation of host rock matter of these

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ages. Secondary Late Triassic (225–230 Ma) alterations did not have a negative impact on commercially valuable sulphide ore stocks. Absence of large amounts of sulphide ores in intrusions of the second (late) group (240–247 Ma), even given assimilation evidence of the same Paleozoic and older rocks (xenocrysts zircon) similar to intrusions of the early group, points to the injection of the late group intrusions into enclosing rocks already depleted in ore-forming components. Direct age determination of sulphide ores by Re–Os isochron method allows to understand the geological interpretation of U-Pb data in zircons. Re–Os data with a surprising constancy match age of about 250 Ma for all studied intrusions. This correspondence reflects a high degree of almost synchronous sulphide Cu–Ni ore formation with the time of magmatism (injection and crystallization of silicate intrusion melt), leaving no grounds for assumptions about the ore system development for tens or hundreds of millions years prior to this stage. Stage dated by zircon at 230 Ma is not associated with sulphide ore formation and reflects the age of the imposed process. Its geological essence requires further study, but is most likely to be identified with Co–Ni–Sb–As vein mineralization of essentially another type manifested in the same massifs. In the course of studies, we have identified significant differences in the isotopic characteristics of intrusions with varying degrees of ore content. These differences can be seen in the summary table; they can be involved as isotopic criteria for the scale of intrusion mineralization. Isotopic characteristics are ranked according to the degree of reliability. Of the three groups, the greatest predictive capabilities provide data on the isotopes of noble gases, helium and argon. We offer a comprehensive isotopic criterion for mineralization of the Norilsk type intrusions: Degree of reliability

Good

Element Isotope ratio Rich

He m, % 1–4

Good

Average

Weak

Weak

Ar S Cu Pb 206 d65Cu, ‰ Pb/204Pb etc. a, % d34S, ‰ 90– 9–13 f (He, Ar) –2…0 f (S, He) 17.90–18.35 f (S) 100 Satellites 0.3–0.7 84–87 5–7 –0.6…–0.3 17.95–18.3 Average 0.5–4 50–80 0–8 –0.8…–0.4 18–15–18.70 Poor 5–22 70–90 0–8 –0.8…–0.4 18.15–18.40 m—share of mantle helium, a—share of atmospheric argon, f—correlation of isotopic parameters

The most promising are intrusions aged at 250–255 Ma with a predominance of atmospheric-crustal argon and helium, with the presence of excess radiogenic hafnium dHf(T) > 5, isotopically heavy sulphur, and fractional copper from sedimentary rocks. The presence of the pre-Triassic zircon xenocrysts is also important. The research results have important theoretical and practical value and can be effectively applied during forecasting and assessment work in the Norilsk district.

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Improvement of measurement techniques and interpretation of results are required, including the development of a rational complex of isotopic measurements as well as carrying out practical assessment of mafic intrusion mineralization in the Norilsk-Taimyr district. Completeness of the collected and prepared material allows in-depth treatment of the following specific tasks: – identify association between the obtained isotopic ages and specific geological events observed in a geological site; – binding dated growth zone of mineral-geochronometer to a complex development stage for local dating methods (ion probe or laser ablation); – computations of the duration and direction of rock evolution, indicative minerals, ore material, duration and thermodynamic regime of ore stage, cooling or rock uplifting rate (geochronology, Cu, Ni); – quantitative assessment of the magnitude and time of crust-mantle interaction as the major ore-controlling factor (isotopic composition of lead, hafnium, sulphur); – assessment of ore-controlling zones depth (by He and Ar systematics); – interpretation and comparison of isotopic dating results of ore and ore-bearing matrix material (Re–Os, Rb–Sr, Sm–Nd systematics); – assessment of the extent and magnitude of fluid—rock interaction as the major ore-controlling factor (isotopic composition of oxygen, carbon, sulphur). The authors would like to thank E.V. Tuganova, K.N. Malich, and I. Yu. Badanina for a great help in getting the unique materials for investigations.