The Geology of Star Basin and Star Mine Gunnison County, Colorado

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THE GEOLOGY* OF STAR SAS III AND STAR MINE GUNNISON COUNTY, COLORADO

By Howard L. G a r r e t t

C o lo r a d o S c h o o l o f M in es G o ld e n , C o lo r a d o March 1 9 5 0

ProQuest Number: 10781402

All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is d e p e n d e n t upon the quality of the copy subm itted. In the unlikely e v e n t that the a u thor did not send a c o m p le te m anuscript and there are missing pages, these will be noted. Also, if m aterial had to be rem oved, a n o te will ind ica te the deletion.

uest ProQuest 10781402 Published by ProQuest LLC (2018). C opyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C o d e M icroform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346

53313

A t h e s i s su b m itted to th e F a c u lty

and t h e

B oard o f T r u s t e e s o f t h e C o lo r a d o S c h o o l o f M in es i n p a r t i a l f u l f i l l m e n t o f th e r eq u ire m en ts f o r th e d e g r e e o f M aster o f S c ie n c e .

S ig n e d Howard L. G a r r e t t

G o l d e n , C o lo r a d o

A p p roved f ." H." VârTTüy'T

ruman H . K

CONTENTS Page A b s t r a c t .................................................................................................

1

.................................................................................................

2

P u r p o se and S c o p e o f I n v e s t i g a t i o n ..........................

*2

In tr o d u c tio n

F i e l d W o r k ................................... P r e v i o u s G e o l o g i c Work A c k n o w led g m en ts G eo g r a p h y

.

2 .

.

....................................

..............................................

. . . . . .

.......................................................................................................

L o c a tio n

............................................................................................

A c c e ss ib ility

..................................................................................

C l i m a t e and V e g e t a t i o n ......................... G e o m o r p h o l o g y .................................................................................

3 4 5 5 5 5 8

G e o l o g y .................................................................................................................. 11 G en eral S tatem en t

.....................................................11

S e d im e n t a r y R o c k s .............................................................................. 12 S a w a tc h Q u a r t z i t e

.........................................................

12

M a n ito u D o l o m i t e .................................................................... 12 C h a f f e e F o r m a t i o n .................................................................... 15 L e a d v i l l e L i m e s t o n e ..........................................................1 7 H erm osa F o r m a t io n

.........................................................

19

I g n e o u s R ock s ...................................................................................

21

P r e -C a m b r ia n R ock s .........................................................

21

N o r t h I t a l i a n M o u n ta in I n t r u s i v e ...........................21

il

_?a&e S tru ctu re

.

.

.

.

...................................................................

23

F a u l t s .......................................................................................

23

F o l d s ...................... ' ...............................................................

27

Summary o f M e s o z o i c and C e n o z o ic G e o l o g i c H i s t o r y ..............................................................

28

Ore D e p o s i t s ..................................................................................................

29

G e n e r a l S t a t e m e n t ..................................................................

.

29

..........................................

30

M i n e r a l o g y ........................................................................................

31

H i s t o r y and P r o d u c t i o n

Secondary M in e r a ls

.

...................................................

31

..........................

31

Gangue M i n e r a l s .............................................................

33

P rim a ry M e t a l l i c M i n e r a l s

C o n t r o l s f o r Ore D e p o s i t i o n

.

. . . . . . . . . .

35

A l t e r a t i o n ........................................................................................

39

T en or o f t h e O r e .........................

40

G e n e s i s o f t h e D e p o s i t ........................................................

40

C o n c l u s i o n s and R e c o m m e n d a t i o n s ...................................

.

.

42

B i b l i o g r a p h y ..................................................................................................

44

T a b le 1

P r o d u c t i o n , S t a r M in e , 1 9 2 7 - 1 9 2 8 . . . .

32

T a b le 2

A b b r e v i a t i o n s U se d on M a p s .................................

45

ILLUSTRATIONS 1

I n d e x map o f C o lo r a d o

2

P a n o ra m ic p h o t o g r a p h l o o k i n g s o u t h a c r o s s S t a r b a s i n , sh o w in g o v e r t u r n e d s e d i m e n t s .

3

.................................................... .

6 9

P h o to g r a p h t a k e n fr o m N o r t h I t a l i a n M o u n ta in l o o k i n g n o r t h e a s t .........................................

10

A r e a n o r t h w e s t o f Mount T i l t o n , l o o k i n g n orth w est ..................................................................................

13

S a w a tc h q u a r t z i t e , s h o w in g r o u n d ed e l o n g a t e d g r a i n s ........................................................* .

.

14

S a w a t c h q u a r t z i t e , s h o w in g h i g h l y a n g u l a r s i l i c l f l e d f r a g m e n t s ........................................ . . .

.

14

7

C hert s t r i n g e r s

.

16

8

C o n t a c t o f C h a f f e e f o r m a t i o n and M a n ito u d o l o m i t e ...................................................................

16

Dyer d o l o m i t e ,

.

18

P a r tin g q u a r t z it e - L e a d v ille lim e sto n e co n ta ct .......................................................................................

18

L e a d v i l l e l i m e s t o n e w i t h l i n e a t i o n due t o e l o n g a t e d c a l c i t e r h om b o h ed ro n s . . . . . .

18

H erm osa f o r m a t i o n a s r o o f p e n d a n t i n in tr u siv e ..................................................................................

20

13

H er m o sa -in tr u siv e c o n ta c t

.........................................

20

14

T h in s e c t i o n o f g r a n i t e , sh o w in g h i g h l y a l t e r e d o r t h o c l a s e and p l a g i o c l a s e fe ld sp a r s . . ...................................................................

22

T h in s e c t i o n o f g r a n i t e , sh o w in g a l t e r e d o r th o c la s e p h en o cry sts w ith in c lu s io n o f b i o t i t e , q u a r t z , and o r t h o c l a s e . . . . . .

22

Q u a r tz m o n z o n i t e , s h o w in g z o n e d p l a g i o ­ c l a s e f e l d s p a r ........................................................................

24

4 5 6

9

10 11 12

15

16

i n M a n ito u d o l o m i t e

sh o w in g i n t e r c a l a t e d

.

. .

sh a le s

iv

FÏKUi-e

P age

17

Q u a r tz l a t i t e d i k e r o c k , s h o w in g p h e n o c r y s t s i n a f e l s i t i c g r o u n d m a s s ................................ 24

18

R id g e e x t e n d i n g e a s t o f N o r t h I t a l i a n M o u n t a i n ..............................................................................................26

19

O v e r tu r n e d a n t i c l i n a l r o l l i n L e a d v ille fo r m a tio n ............................................................

26

20

G a le n a e m b a y in g l i m e s t o n e

34

21

B a r i t e i n l i m e s t o n e ................................................................. 34

22

U n c o n s o l i d a t e d sa n d o f s o l u t i o n c a v i t i e s , sh o w in g a n g u l a r i t y o f g r a i n s ........................................

...............................................

36

23

M i n e r a l i z e d b r e c c i a ................................................................. 36

24

S t a i n e d b r e c c i a ............................................................................38

25

M a t r ix a ro u n d b r e c c i a f r a g m e n t ........................................38

P la te ......................................

pocket

1

D r a i n a g e map s h o w in g g e o l o g y

2

S tr a tig r a p h ie

s e c t i o n and t r a v e r s e ............................

,f

3

C la im m a p .........................................................................................

”

4

W o r k in g s o f S t a r m in e

11

5

G e o lo g y o f w o r k i n g s ab ove f i r s t l e v e l

6

G e o lo g y o f f i r s t

..........................................................

”

7

G e o l o g y o f h a l f l e v e l ..........................................................

”

8

G e o lo g y o f s e c o n d l e v e l

n

9

G eo lo g y o f t h i r d l e v e l

le v e l

..................................... . . .

w

..................................................... .......................................... se c tio n

”

10

G e n e r a liz e d s t r a t ig r a p h ie

..........................

11

G e o lo g ic c r o s s s e c t i o n through r id g e l i n e

.

27A

12

G eo lo g ic c r o s s

.

39A

s e c t i o n t h r o u g h S t a r m in e .

11A

ABSTRACT The S t a r b a s i n ,

a c ir q u e

a t t h e b a s e o f N o r th I t a l i a n

M o u n ta in on t h e w e s t e r n rim o f T a y l o r P a r k , i s n o r t h e a s t o f the c i t y

55 m i l e s

o f G u n n is o n i n G u n n iso n C o u n t y ,

C o lo r a d o . N o r t h I t a l i a n M o u n ta in i s d e v e l o p e d upon a T e r t i a r y , m o n zo n ite s t o c k t h a t in t r u d e s a P a le o z o ic tio n , tio n

com p osed e s s e n t i a l l y

se d im e n ta ry s e c ­

o f ca rb o n a te r o c k s.

T h is s e c ­

i n c l u d e s t h e S a w a tc h q u a r t z i t e . M a n it o u d o l o m i t e ,

C h a f f e e f o r m a t i o n , L e a d v i l l e l i m e s t o n e , and Hermosa fo r m a ­ tio n .

At S t a r b a s i n t h e f o r m a t i o n s a r e i n r e v e r s e

sequence

b e c a u s e o f o v e r t h r u s t i n g 1 fro m t h e e a s t . The o x i d i z e d o r e s o f t h e S t a r , m in ed f o r t h e i r l e a d and s i l v e r c o n t e n t ,

are fou n d in a zone o f lim e s to n e b r e c ­

c ia in th e L e a d v ille fo r m a tio n . sto n e b r e c c ia i s m in e r a ls

D ir e c t ly o v er th e lim e ­

a z o n e c o n t a i n i n g sa n d p o c k e t s .

are found in l e n s e s

S u lp h id e

or pods i n unbroken L e a d v i l l e

l i m e s t o n e a b o v e t h e l a y e r c o n t a i n i n g t h e san d p o c k e t s and b e lo w th e b r e c c i a zo n e.

a r t h u b l a k e s l ib r a r y

COLORADO SCHOOL OF MINES GOLDEN, CO 80401

INTRODUCTION p u r p o s e and S c o p e o f I n v e s t i g a t i o n The g e n e r a l g e o l o g y o f S t a r b a s i n w as s t u d i e d t o d e ter m in e th e c o n t r o l s f o r m i n e r a l i z a t i o n . c a r r i e d o u t u n d e r g r o u n d a s w e l l a s on t h e c lu d e d th e stu d y o f th e

str a tig r a p h y ,

The w ork was su rfa ce

s tr u c tu r e , p etro g ra ­

p h y , and m i n e r a l s t u d i e s , i n c l u d i n g p o l i s h e d Id e n tific a tio n

and i n ­

se c tio n s.

and a g e c l a s s i f i c a t i o n o f t h e s e d i m e n t ­

a r y f o r m a t i o n s was made b y l i t h o l o g i e

and s t r a t i g r a p h i e

r e l a t i o n s h i p s , b a s e d on p u b l i s h e d d a t a o f t h e s u r r o u n d i n g d istr ic ts.

F i e l d Work The f i e l d w ork f o r t h i s 1949,

s t u d y was commenced i n J u l y ,

and was c o m p l e t e d by t h e en d o f A u g u s t o f t h e

year.

IT. S . F o r e s t S e r v i c e

o f 4 In ch es to a m ile served C .D .L .

same

a e r i a l p h o t o g r a p h s on a s c a l e as a b a s e f o r s u r f a c e m a p p in g;

3 2 -4 1 th rou gh 3 2 -4 4 i n c lu s i v e

a r e t h e num bers on t h e

p h o to g ra p h s flo w n O ctob er 2 2 , 1 9 3 9 . The u n d e r g r o u n d m in e maps s u p p l i e d by Mr. L a m b e r ts o n , m in e o p e r a t o r , w ere p r e p a r e d b y m eans o f a B r u n t o n - a n d - t a p e s u r v e y on a s c a l e o f 1 i n c h t o 40 f e e t .

They w ere s u p p l e ­

m e n te d b y a d d i t i o n a l maps b a s e d on a s u r v e y by t h e a u t h o r .

3 The e l e v a t i o n o f S t a r m in e i s

1 1 ,6 0 0 f e e t ,

and a l p i n e

w i l l o w s and E n gelm ann s p r u c e grow a b u n d a n t l y a t t h i s tio n .

e le v a ­

T h is c o v e r , c o m b in e d w i t h g l a c i a l m a t e r i a l , m akes

s u r f a c e m ap p in g v e r y d i f f i c u l t ,

e s p e c ia lly

i n to p o g ra p h ic

lo w s ; t h u s , t h e s u r f a c e m app ing was b a s e d l a r g e l y on o u t ­ c r o p s fo u n d on r i d g e s

and s l o p e s .

The a r e a l d i s t r i b u t i o n

o f th e fo r m a tio n s th a t o u tcro p in S ta r b a s in i s on t h e d r a i n a g e map ( p l .

1,

rep resen ted

in p o c k e t).

P r e v i o u s G e o l o g i c Work The p r i n c i p a l p u b l i s h e d a r t i c l e s

on t h e g e o l o g y o f

S t a r b a s i n e x a m in e d i n t h e p r e p a r a t i o n o f t h i s

th e sis

are

as f o llo w s ; I n 1 9 3 1 and 1 9 3 4 J . H a r l a n J o h n so n m e a s u r e d a s t r a t i ­ g r a p h i e s e c t i o n n e a r N o r t h I t a l i a n M o u n t a in , w h ic h w as p u b ­ lis h e d

i n t h e B u l l e t i n o f t h e G e o l o g i c a l S o c i e t y o f A m e r ic a

f o r March 1 9 4 4 .

The t i t l e

of th is

a r tic le

is

" P a le o z o ic

S t r a t i g r a p h y o f t h e S a w a tc h R a n g e , C o l o r a d o . 11 C r o s s and Shannon s t u d i e d t h e i n t r u s i v e i a n M o u n t a in and p u b l i s h e d t h e i r r e p o r t ,

o f N orth I t a l ­

" G e o lo g y o f I t a l ­

i a n M o u n t a in , G u n n iso n C o u n t y , C o l o r a d o , " i n t h e P r o c e e d ­ i n g s o f t h e U n i t e d S t a t e s N a t i o n a l Museum ( v o l . 2690, S ep t.

7 1 , no.

26, 1 9 2 7 ).

The S t a r m ine and a r e a w as I n c l u d e d i n m in in g d i s t r i c t

th e T in c u p

i n A lb e r t W o lf 's 1915 g e o l o g i c r e c o n n a is ­

sa n ce r e p o r t o f th e

area.

T h is r e p o r t i s

in g p r o p e r t i e s , th e C o llin s f i l e s ,

In a f i l e

o f m in ­

o f t h e C o lo r a d o S c h o o l

o f M in e s l i b r a r y . ARTHUR LAKES LIBRARY COLORADO SCHOOL OF MINES GOLDEN, CO 80401

4

A c k n o w le d g m e n ts The a u t h o r w i s h e s t o e x p r e s s h i s a p p r e c i a t i o n t o t h e f o l l o w i n g f a c u l t y members o f t h e D e p a r tm e n t o f G e o l o g y , C o lo r a d o S c h o o l o f M in e s ;

D r . Truman H. Kuhn f o r s u p e r v i ­

s i o n and s u g g e s t i o n s i n c o n n e c t i o n w i t h f i e l d w ork and t h e p r e p a r a tio n o f th e t h e s is ; c r itic ism

o f th e t h e s i s ;

D r . P . M. Van T u y l f o r e d i t o r i a l

D r . W. R. W agner f o r s u g g e s t i o n s

i n th e p é tr o g r a p h ie s t u d i e s , s io n in th e f i e l d ; sed im e n ts;

and p h o t o g r a p h y and s u p e r v i ­

D r. L. W. LeRoy f o r s t u d i e s

o f th e

and Mr. K. S . H e r n e s s f o r s u g g e s t i o n s i n t h e

p r e p a r a t io n o f m aps. Mr. L a m b e r t s o n , m in e o p e r a t o r , g a v e p e r m i s s i o n t o w ork i n t h e a r e a and t h u s made t h i s

stu d y p o s s i b l e .

A p p r ec ia ­

t i o n m u st a l s o b e e x p r e s s e d t o him f o r h i s g u i d a n c e i n t h e fie ld

and t h e i n f o r m a l d i s c u s s i o n s o f t h e g e o l o g y o f t h e

a r e a and p a s t h i s t o r y o f t h e S t a r m i n e .

GEOGRAPHY L o c a tio n S ta r b a sin , M o u n t a in , i s

a c ir q u e a t th e b a se o f N orth I t a l i a n

on t h e w e s t e r n r im o f T a y l o r P ark a b o u t 55

m i l e s n o r t h e a s t o f G u n n i s o n , G u n n is o n C o u n t y , C o l o r a d o . F i g u r e 1 sh ow s t h e l o c a t i o n o f t h e a r e a s t u d i e d .

A c c e ss ib ility S t a t e H ighw ay 1 3 5 , n o r t h o f G u n n i s o n , i s w i t h i n one m i l e o f A lm o n t , s e r v e s T a y l o r P ark ( f i g .

paved to

and fro m h e r e S t a t e H ighway 306

1 ).

The r o a d t o t h e m in e fr o m

H ighway 306 i s m a i n t a i n e d b y Mr. L a m b e r ts o n , m in e o p e r a t o r . The r o a d t h r o u g h T a y l o r P a rk a b ov e T a y l o r P a r k dam i s

not

k e p t o p e n d u r i n g t h e snow s e a s o n . The o r e fr o m t h e m in e i s h a u l e d by t r u c k t o A lm o n t, 38 m i l e s , w h er e i t

is

dumped o n a s i d i n g o f t h e D e n v e r and R i o

G rande R a i l w a y f o r v ille ,

t r a n s p o r t a t i o n to th e s m e lt e r a t L ead­

C o lo r a d o .

C l i m a t e and V e g e t a t i o n The m o u n t a in o u s s e t t i n g by lo n g c o ld w in te r s th e e le v a t io n

o f S ta r b a sin i s

and s h o r t c o o l sum m ers.

(1 1 ,6 0 0 f e e t )

c h a r a c te r iz e d B ecguse o f

p a t c h e s o f snow c a n b e s e e n

w

111

L __."

INDEX

MAP

OF

----- 1_1

COLORADO

___ I

—r Ll

7

th e y e a r around, w h ile

a f t e r n o o n s h o w e r s and h a i l s t o r m s

o c c u r f r e q u e n t l y d u r i n g t h e summer.

The r o a d fr o m S t a r

b a s i n t o T a y l o r P a r k b e c o m e s c l o s e d by snow a s e a r l y Movember, and I t i s f o r e th e road i s

t h e l a s t o f May o r the- f i r s t

as

o f June b e ­

a g a in p a s sa b le ; t h i s le a v e s a sh o r t h a u l­

i n g s e a s o n , w h ic h c o u l d b e l e n g t h e n e d i f

a b u l l d o z e r w ere

a v a ila b le . The e l e v a t i o n o f S t a r m ine a p p r o x i m a t e s t h a t o f t i m b e r lin e

In t h i s

r e g io n .

The h e a d - f r a m e o f t h e S t a r s h a f t

i s made fro m E n glem ân s p r u c e t h a t w as c u t i n t h e v i c i n i t y o f t h e m in e .

A t 1 1 , 6 0 0 f e e t t h e E n glem an s p r u c e i s

s l o p e s and r i d g e s , w h i l e th e c r e e k b a n k s. th e A r t ie w illo w

th e A r tie w illo w f lo u r is h e s

on t h e a lo n g

F or a s h o r t d i s t a n c e above t im b e r lin e i s fo u n d ,a n d above t h a t o n ly g r a s s e s .

As

t h e e l e v a t i o n d e c r e a s e s , t h e A sp en and y e l l o w p i n e r e p l a c e t h e E n g lem a n s p r u c e .

The t y p e o f v e g e t a t i o n t h u s show s a

m arked d e p e n d e n c e on t h e a l t i t u d e .

8

GEOMORPHOLOGY N o r t h I t a l i a n M o u n ta in r e p r e s e n t s a t o p o g r a p h i c h i g h fo r m e d b y d i f f e r e n t i a l

e r o s i o n o f an o v e r t u r n e d P a l e o z o i c

s e d i m e n t a r y s e c t i o n i n t r u d e d by a s t o c k o f q u a r t z m o n z o n i t e . D u r in g g l a c i a l t i m e t h i s

to p o g r a p h ic h ig h s u f f e r e d in t e n s e

e r o s i o n and s e v e r a l c i r q u e s w e r e d e v e l o p e d ,

in c lu d in g S ta r

b a s i n on t h e n o r t h e a s t f l a n k o f t h e m o u n t a in . The r i d g e show n i n f i g u r e

2 w as fo r m e d b y t h e c o a l e s c ­

i n g o f tw o b a s i n s , t h e S t a r b a s i n and t h e c i r q u e b a s i n a t th e head o f S p rin g C reek , d i r e c t l y th e background.

At th e ex trem e l e f t

p r e - C a m b r ia n g r a n i t e r e s t s o f th is

so u th o f th e r id g e in o f t h i s p h otograp h ,

on th e s e d im e n ts ;

r i d g e a s w e l l as o t h e r s i n t h e

th e b a la n ce

area are h e ld to p o ­

g r a p h ic a lly h ig h by th e g r a n i t e . The v a l l e y s w e r e fo r m e d b y g l a c i e r s c u t t i n g b e l o w t h e g r a n ite

in to th e l e s s - r e s i s t a n t

c a r r i e d away b y e r o s i o n .

s e d i m e n t s w h ic h w e r e l a t e r

The g l a c i a l l a k e s , p r e s e n c e o f

p o o r d r a i n a g e , g l a c i a l e r r a t i c s , and m o r a i n a l m a t e r i a l in d ic a te

th e a c tio n o f g l a c i e r s

(see f i g .

3 ).

9

cti CO CO O •H

#3

E

F-, in I S ' Q Q ef o / f o b f t / e - /bfactf. d f f b e b a s e o f f b e f o r m a f/on, f b e r e /s o f O’ b e d o f m ed /a m g ro / n e d b u f b eo/orecf, epaorfy sondsfone, wb/cb t e n e s /o f e r a /f y c /n d /S f o u n d /a fey? /e/ace's. taca//jf. f b /s m a y f>e f b e f T s /s r /e s s m e m b e r:

o

z < or 00 s < o

I p *2
ed d /n y on e/ C oarseness o f g ro/n /s s om eyybof m o r e / o r o n o u n c e d n e a r fb e d ose. 7~bere / s a a on g fo m e ro f/c f a c /e s n e a r f b e

CO

CO CL

mm

f b e y r e Co m/b r a /// co m y fe x c o n s /s ty t a r g e / y o f g r a n /f /c rocks t h a t c a r r y m /n o r /ncfus/ons o f gne/ss. Phe g ra n /te s r a r y /n tex tu re s fro n t a y f / t / c t o y o r y h y r / f / c .

12

S e d i m e n t a r y H ock s The s e d i m e n t a r y r o c k s o f t h e a r e a a r e a n u n f o s s i l i f e r o u s g r o u p o f d o l o m i t e s , l i m e s t o n e s , s h a l e s , and q u a r t z i t e s a l l o f P a le o z o ic

age.

The s e d i m e n t a r y

s e c t i o n was s t u d i e d

on a r i d g e r u n n i n g n o r t h w e s t fro m Mount T i l t o n The g e n e r a l i z e d s t r a t i g r a p h i e c o lu m n ( p i . th e s t r a t ig r a p h ie

cross se c tio n

was m e a s u r e d a l o n g t h i s

(p i.

2,

10)

(fig .

4 ).

i s b a s e d on

i n p o c k e t ) w h ic h

r id g e .

The f o r m a t i o n s w e r e i d e n t i f i e d o f p u b lish e d d e s c r ip t io n s

in th e f i e l d

and s t r a t i g r a p h i e

by t h e a i d

se q u e n c e , w h ile

t h e a g e d e t e r m i n a t i o n s w e r e b a s e d on a r e v i e w o f t h e l i t e r ­ a tu re

(3 , pp. 2 2 1 -2 2 3 ).

S aw atch Q u a r t z i t e The S a w a t c h q u a r t z i t e i s

a w h ite , v it r e o u s ,

c o a r s e -g r a in e d , cross-b ed d ed q u a r tz ite . e x t r e m e l y c o a r s e and i n p l a c e s i s (fig s.

5 and 6 ) ,

e lo n g a tio n . b e d d in g i s

fin e -

to

The b a s a l p a r t i s

a c o n g lo m e r a tic q u a r t z it e

t h e p e b b l e s o f w h ic h show d i s t o r t i o n o r

The b e d d i n g i s m a s s i v e and I r r e g u l a r ;

cross

pronounced th ro u g h o u t th e fo r m a tio n , b u t i s

d o m in a n t t o w a r d s t h e b a s e . The S a w a t c h q u a r t z i t e l i e s C am brian c o m p le x and i s

u n c o n f o r m a b ly on t h e p r e -

C am brian i n a g e .

M a n ito u D o l o m i t e The t h i c k n e s s

o f t h e M a n it o u a t S t a r b a s i n i s

m a t e l y 3 8 0 f e e t , and i t th e m ost p a r t .

is

a p p r o x i­

a d e n s e , b lu e - b la c k d o lo m ite f o r

The b e d d i n g i s

q u ite

r e g u la r ,

and t h e i n d l -

13

i -P

CO

-p

m a) c

hO-H

CA

•H |—I

S & o ^ (P, m o

00 -p -P

to o

CD , P-. ç /x) O / a y Ù / e c o / a ~ / ) r g t / > / y n / f e y e . ’/

f". / .'y,. y/ ' : . J

Arc. r. ' S'/p

ÎF /J/ o /io /y rctr/es-ra/

- /c s?.-/

5- o/c

- c-1

r r-c -s s c o f cv-A/otrrcf Ac u A f tr / c y Acr-c r c /« Frer-/ / r o y /r-.r o/.'-

^ b S acre/ ctsr/oenofc's //? sorrc/ An/A/y

&/fo/ cAferçcçrçCj r-1per f~Ç C-IYG^V /A?/?oy Apr-crccrp Aric-’y

e/a y

PLATE 6.

GEOLOGY AND WORKINGS OF FIR ST L E V E L

STAR MINE SCALE 4 0 ' 3 d 2 0 ' Id

I IN = 4 0 O

FT.

20'

40'

LEGEND LIMESTONE j MINERALIZED ZONE UNCONSOLADATED SAND FAULTS

W s is m m iZIZTIZJ

— t------

J4* 30'

3 recc/a - / ? f . k V rsy jo r a eut t / u f / f fe a p n e e ifs . Crystal/m e

im. o a f If.

i f,f t.

c o a rse /y

0 /toKens/des 3 0 “i f p / u ny e-

/e?c/epee? c/e e rf /a cf/ep e , f e / / e o /

-Jno/epaeidenf staff

/m .

l ' fcc-r I a r

'^oanso too-Soai and cry's r o ■'Or:a, taO f /en. a/ferat/ori ft?an a t ent'once.

c h e r t fr a g s n e r ffj

/g s s

flty /liy o ifr r e d f r e c c / a c o n fa /n /e /y c r fi/a c ta n f s p a r a e id F e o x id e s . S p a r c u t s o f f ss. p a c k e t s , /n o th e r p ta c e s tr e c c /a c u ts o f f th e p o c k e t s -F t5 /e> a if e r e c / b r e c c /a , + s p a r ,a e /d Fe ax/des, e/ay /ee}/nç Tfl'J is a t frays asxoc /eefed xte/tf saerd necMetx^ patc/ij of t /'a ce so sh o ne/en? fJ?r.-apA A/o. /

/stc/.-ste,

t'//.'ere/

~tk o . 3

s te r e

ttrercc/c' tl/ÿA/y ctteree/^ ecbuee/asrt .

//o f s o ///te r/e e

■t.pr/T cyrey /zzz F e ox/ofes-

Fet>y o/rcfat/on a net s-jr/ar

st/grf/t,

som e

PLATE 9. GEOLOGY

AND WORKINGS OF THIRD L E V E L

STAR MINE SCALE

I IN. = 4 0 F T

4 0 '3 d 20' 10' O

20

LEGEND LIMESTONE MINERALIZED ZONE UNCONSOLADATED SAND FAULTS jY

V

S ’^ercc/o co/ jf a/ n/ Oy J/qfrt a n d JTr/rtyer, - f t r s-fam

1403 0 '

a/arM' /m J f r a c tu n e -d c-Arrf

S - c /a y b u ff

çroagej norfA o f f ’ac/ff f/es a g r e y Jm. ' S+COa,

d ~ ff/M' cjoag'ci sfat?/ grrcjc //r? b/A' ana/ g r a y cAerf sfr/ncj,

£ fr c c c /a

i^or/a/ns

see m s

r'siSj xS'O »/7û/

/ess

J ’

a/ferec/^ jaredo/n/nat/y g r e y /m

o yidired /n a fe r /a !

/z ;

a

f^e

s fa m e d

jbrecc/a c-e/ne-n f e d yis/ffl

-/!%>lsnctan f c / e - r f S'fr/n g e r s sa /'rac C a re g a . f a S'asrdy, b /u /m /r a g m e n f s f/’r e c c ta becom es fess Jt f/g c u g e^

C/ e r f

Lrn. b ecom es

Pau/f

fra g /m e n fs,

d o r // / e

sostc/yj m e re

q/ayey^ g r e y /m jorecfom m efes

//a ffe n s near- //o a rj

a o f /O"

f/g fit fm yredoa?/r?af/es

ffb S s o r d

■n/nor a/n f a /

C'a. S'fa/n

e.