Natural History Digging beneath the Silk Road

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Digging Beneath the Silk Roa Do the sands of China’s “sea of death” conceal the tracks of early hmans?

by John W. Olsen Arid plateaus, pebble-strewn plains, and desert basins seem unpromising places to look for signs of prehistoric humans. Yet earlier this century, major international expeditions, including those of Roy Chapman Andrews for the American Museum of Natural History, scoured the wastelands

of

Mongolia

and

western

China for fossils, under the assumption that central Asia was the cradle of humanity. As far as early human fossils are concerned, these expeditions returned emptyhanded. We now know that the earliest human ancestors lived in Afr . as lor three million years ago, while their descendants left no clear traces in Asia before about one million years ago. But some of the world's best preserved specimens of our ancestor Homo erectus,

which arose in Africa about 1.6 million years ago, have been found in East Asia. Among are the remains of Peking

man from Zhoukoudian in northern China, where cave deposits have yielded fossils of at least forty-five individuals, along

with thousands of stone tools and other cultural debris. Other finds come from northern India and the western regions of central Asia, especially Uzbekistan. As uninviting as they seem today, the regions in between must have been traversed in ancient times, or even occupied. Hoping to uncover some overlooked prehistory, I have been investigating the southern

margins

of the Tarim

Basin, a

130,000-square-mile depression in China’s Xinjiang Uygur Autonomous Region. The basin contains one of the most

formidable arid areas on earth, the Taklimakan Desert. Larger than New Mexico, the Taklimakan figured prominently in China’s dynastic history as a barrier to East-West communications. The great

Silk Road, which once linked the Chinese and Roman em edge of northern and again on the is now the

empires, divided on the eastthe basin, passed along its southern margins, and joined western periphery, near what frontier between China and

Kirghizstan. Many of the spring-fed oases that once served as caravansaries along the southern arm of the Silk Road have been 30

NATURAL

HiSTORY 9/92

A dust storm near Turpan engulfs the ruins of a city on the Silk Road, the overland trade route that linked China and the West beginning in the sixth ary Wlinsicy; Trik

century B.¢

buntains in western China. Map, below: The narrow piedmont [ion between the formidable Taklimakan Desert and the towering lun Mountains may have been a hospitable patiway for 4y human ancestors migrating through Asia.

Hetian River

ums. Since proper archeological procedures were not yet developed, let alone followed, this flurry of antiquarian inguiry destroyed many of the important clues that are uncovered during excavation; it also failed to yield any substantial evidence of the Tarim Basin’s carliest populations. The Taklimakan Desert proper—a nearly featurcless expanse of sand with dunes up to 300 feet high—is uninhabited; a popular Chinese term for the area is

wang zhi hai, or “sca of death.” Early explorers often wrote in awed tonés of the

much-feared storms,”

kara-buran,

that engulfed

whole

or “black caravans

during some seasons of the year and were, in part, responsible for giving the Taklima-

kan Desert its evil reputation among travelers. Having experienced what 1 consid-

ered to be harsh sandstorms several times in the Sahara Desert, 1 was curious abont

the dreaded kara-buran. In 1987, my coriosity was more than satisfied. Late one afternoon as the wind began to pick up, my colleagues and [ returned to a small village nearby to pass the night indoors rather than slecp out under the stars. In the wee hours of the morning we were awak-

ened by a ferocious, howling

wind.

Switching on our flashlights, we found we

could not see our hands before our faces. The room was filled with a mist of talcompowder-like sand so dense that our flashlight beams resembled glowing solid bars. The dust was thick and choking; T finally

fell asleep with a damp handkerchief tied rallowed by the shifting sands, evidence

facts from the early Chinese dynasties, the

at the desert has spread in historic times.

Han (206 B.C.—A.D. 220) through the Tang

/en the once-great trading center of

(A.0. 618-907). Beginning in the midnine-

hulan, located just west of an ephemeral Lop Nur, was apparently unable to pport its burgeoning population when lake became permanently dry, and was

teenth century, scholars from nearly every comer of Europe, America, and Japan

andoned in the carly fourth century A.D.

hen Marco Polo passed through his thoul-infested Desert of Lop™ in 1224,

bulan had already lain beneath the sands r nearly a thousand years. Today China 1s her nuclear weapons in this region. Numerous archeologists have explored southemn Silk Road searching for arti-

flocked to northwest China to investigate claims of ruined cities and richly furnished burial grounds in the heart of the Taklimakan Desert. One after another, leading explorers of the day such as Przewalsky, Hedin, Stein, Pelliot, Otani, and Le Cog found peasants’ reports of lost cities and cemeteries to be true, and all carried off

across my nose and mouth to filter out the larger particles. When we awoke the next moming our room resembled an archeo-

logical dig itself—everything, including us in our sleep, had been covered by an inch or more of the Taklimakan's notorious sand. (We also learned that in October

1986, several dozen residents of southern Taklimakan oases were asphyxiated when a particularly violent kara-buran caught them far from any shelter.) People do live along the Tarim River

valley, which forms the northern border of the basin, and in the string of more than

vast quantities of Chinese relics to adom

fifty oasis settlements found on the south-

the exhibit cases of their national muse-

em fringe of the sand sea. Today these 33

Jefirey Aford; Asia Access

Ancient river deposits on the sides of the Niva River gorge, below, are a promising site for archeological exploration. The Kunlun Mountains, right, are the northern range of the Himalayas. Right, below: Goats graze near the northern

margins of the Taklimakan Desert.

Jobn W, Oksen

oases are occupied mainly by a Muslim Turkic nationality, the Uygur (Taklimakan itself comes from the Uygur word meaning “labyrinth™). Most scholars belicve that the Uygur are comparatively recent arrivals, having settled in southern Xinjiang sometime after the ninth century A.D., when they fled Mongol domination on the central Asian steppes. These agriculturists grow fruit and grain in settl

ments ranging in size from a few fam supported by a dozen acres of cultivated land to such huge aggregates as Hetian (Khotan) Oasis, which has a population of roughly 1.2 million. To the south lies the Kunlun massif. the northern flank of the world’s tallest range, the Himalayas. The peaks reach up to

23,000 feet above sea level, or 19,300 feet above the Taklimakan sand sea; they are

called the mountains of darkness because they are largely shadowed when viewed from the north. During our ficldwork in southern Xinjiang, we made a side trip into the foothills

sources Basin. sonally River;

of the Kunlun Mountains to visit the small

soak in and disappear beneath the Takli-

village of Chahar, not far from the Tibetan frontier. Sir Aurel Stein, a great British explorer, had passed through here in 1907

makan’s thick mantle of sand. The historic Silk Road cities—Dandanoilik, Niya, Karadong, Endere, and a host of others— were associated with major rivers, but thousands of smaller watercourses parallel them. Today many are inactive or carry water only seasonally. Apart from the spring-fed oases, these sites seem to represent the only places in the southern Tarim Basin where large groups of people could have lived in the past. Although the cores of some of its deserts date back 65 million years, central Asia was relatively moist during much of the Pleistocene epoch, which lasted from roughly 1.8 million to about 12,000 years ago. During the extended periods of glaciation that characterized the Pleis-

and had indicated the small cluster of mud-brick houses on his maps. Arriving in the village on market day, we were confronted by hundreds of curious Uygur

farmers and their families. who called out, “Look! Forcign friends!” as we passed. In this realm where even Chinese people are an oddity and Beijing is a mythical city far to the east, we were not surprised to learn that we were the first foreigners of any nationality that most had scen. What did take us by surprise was an elderly man who re-

membered the day Aurel Stein and his party entered Chahar on horseback; he recounted to us how he, as a child of eight,

in Kunlun glaciers into the Tarim Only the Hetian River flows seaacross the desert to join the Tarim all the other watercourses simply

had run after the horses, shouting and

tocene, when snow cover and glacial

laughing, exactly as the village children had done on our arrival by Land Cruiser.

packs of the Kunlun

Mountains were

and acted as a natural conduit for hunt gatherers traveling back and forth fromt montane steppes of western central AS

to the hilly, deciduous forests of the CI nese interior. With this in mind I set o with a team of scientists in 1986 to surw| the Kunlun

piedmont and the adjacel

desert, focusing on a sixty-mile-long ment between the Hetian and Cele Upon arriving, I decided the most tical way to learn about the Tarim Bas| was 10 take a public bus that traveled al its margin. Even today, foreigners are

uncommon on public transportation

heavier, the piedmont gobi must have sup-

side the major tourist centers, but in |

my presence for the duration of W

gravel-paved plain. This piedmont area,

ported richer plant and animal communities. Standing between the impassably high Kunlun peaks and the barren wastes

h serves as a watershed, is dissected by watercourses that flow north from their

offered resources to human

In between the mountains and the desert is a sloping, thirty-mile-wide gobi, or

34

NaruraL HisTory 9/92

of the Taklimakan, this area would have populations

turned out to be a ten-day journey

quite a stir. I was immediately adopted several older women, who made sure I enough fresh mulberries to eat from

along the roadside and paid the appropi ate prices for noodles and mutton at ea of our rest stops. One of my fondest memold Uygur gentleman for days on end, neither of us speaking the other’s language. Somehow I got across (o him that I had

would gently tap me on the shoulder and point out some unique desert feature—a falcon carrying off its pre n unusual

dune formation, the ruins o way between Kashgar and Hetian. hugged me and gave me his br: western Tarim Basin is renowned thro

out central

Asia

he

2 with valuable information from mers familiar with the lay of the land, we used high-tech remote-sensing systems to identify the types of geological

settings most likely to yield prehistoric sites. We pored over data from dsat’s multispectral scanners and thematic mapper and the space-shuttle-based large format camera. In addition, we made use of the shuttle-borne synthetic aperture radar (SAR), which had already enabled archeologists to peer for the first time beneath the surface of the Sahara Desert. Able to

pick out features as little as 130 feet wide, SAR can expose ancient river channels and other geological features that lie beneath the san g rently exist for only the eastern margin of the Tarim Basin, but they have taught us what aboveground features to look for that 36

NaTUrRAL HiSTORY 9/92

Nevaga Vier

Uygurs make soup, left, in the butchery

section of the large

market held each Sunday near Kashgar. A vendor offers platters and kitchenware, lefi, below, in the city’s daily market

Below:

The interior of a Uygur home in Kashgar.

Galon Rowet, Mountain Light

have blown away the soil, leaving only a jumble of artifacts on the surface representing thousands, perhaps tens of thousands, of years of human history. The 1986 survey enabled us to identify the most promising places in which to

concentrate our future efforts. At the end 2 likely to be near buried extinct water1ys and oases.

‘The complex winds in the Taklimakan, cluding the much-feared kara-buran, e also important agents in exposing cheological remains. Early explorers of

uthern Xinjiang recognized that cataysmic storms often brought to light ces of early historical settlements. pace-borne remote sensing has proved tremely useful in identifying interdunal

of that expedition, we also found our first evidence of early prehistoric human occupation. In the midst of the towering dunes of the southern Taklimakan sand sea, we

discovered a half dozen exposed gobi surfaces with archeological remains. These were simple, flaked quartzite tools, such as choppers and chopping tools—pebbles that have been irregularly chipped along one or two edges to produce a sinuous yet effective cutting edge. These sites, which consist of little more than scatters of stone

tools, are difficult to interpret but may be

20,000 and 15,000 years ago, a time when

some regions of the world became uninhabitable. So far these tools represent the

carliest-known evidence of human populations in Chinese central Asia. (For a discussion of the possible significance of pebble tools in Asia, see “Bamboo and

Human Evolution,” Narural History, October 1989.)

In 1987 and 1990, I returned with geographer Richard W. Reeves and archeologist Sari Miller-Antonio, both colleagues from the University of Arizona: archeologist Huang Weiwen of the Chinese Academy of Sciences; and geologist Lei Jiagiang of the Xinjiang Institute of Biology, Pedology, and Desert Studies. We set up a

staging point in the Hetian Oasis in order to explore the south-central rim of the Tarim Basin, particularly the valleys of the Karakax (Black Jade), Yurungkax (White

bekets, or “blowouts,” where ancient ind surfaces are exposed, often yielding

the remains of temporary hunting camps.

Quartzite pebble choppers are not much

Jade), Cele, Keriya, and Niya rivers. We

icheological materials otherwise discovable only by chance. Similarly, artifacts fve turned up in the desiccated sediments

to look at, but we were gratified to uncover them since they bore no resemblance to later Stone Age materials that have been

followed the courses of these principal rivers both north into the parched heart of

| marshes and lakes dating from soon

found elsewhere in the southern Tarim

point where they issued from the flanks of

ter the end of the Pleistocene. These sedents must have been covered up rapidly,

Basin. The choppers were associated with geological strata dating to the last major cold snap of the Pleistocene, between

the Kunlun Mountains.

herwise the Tarim’s fierce winds would

the Taklimakan Desert and south to the The gravel piedmont proved to be the

most fruitful area for our search, since the

A camel's back, right, provides secure

passage for a Uygur family in the Pamir| Mountains. Below: A Uygur shepherd and his daughter at the family's

major rivers had cut deep canyons in some places, leaving a series of terraces, or remnant banks. The archeological remains found along these terraces can be assigned ges, enabling us to determine whether they are from Pleistocene times or more recent. Simple chipped-stone choppers and chunks of quartzite used as a source of raw material also turned up near smaller waterways, many of which are now extinct but which once flowed at least seasonally.

Other sites lay on the middie reaches of the Keriya and Niya rivers. These con-

sisted of surface scatters of stone tools, sometimes

accompanied

by shallowly

buried scrapers, choppers, and other chipped-stone artifacts of the same age. In

several cases, artificial alignments of rocks and boulders appeared to be the surviving foundations of simple lean-to huts and animal-hide shelters. Located on an-

cient river banks, such sites reflect a time when the Tarim Basin’s resources were abundant and game flourished along the margins of these now-dry stream beds. The surface finds and excavated materi-

als demonstrated at least two periods of prehistoric

human

occupation

in the

southern Taklimakan. One, which we cor-

ginnings of food production in central Asia. Microliths arc gencrally associated with hunters, however, suggesting that if these were farmers they nevertheless continued to supplement their diet with game

permanent winter quarters. Nevada Vier

and probably wild plants, perhaps on a scasonal basis.

In contrast to the nomadic or seminomadic Pleistocene hunters, these later people may have lived most of the year in settled homesteads, even villages. Since our finds do not include substantial house foundations or cemetery sites, they may only represent seasonal camps. Possibly the inhabitants gathered in larger settlements during part of the year but dispersed atother times, according to the local availability of water and of wild resources such as migrating herds of game. So far we have no proof of a human presence before 20,000 years ago. In addition, our archeological record has two gaps. One, from 15,000 to 7,000 years ago, came between the Pleistocene huntergatherers and the makers of microliths and pottery. Another gap followed the disappearance of the microlithic tools about 4,000 years ago and the florescence of the Silk Road trading centers, such as those represented by the first century B.C. ruins

in the oases of Hetian, Yutian, and Min-

that resource. Later on, people equipp with some knowledge of food producti could have found the region more ho pitable. But they too may have exhauste

local resources and been forced to moy elsewhere. A central purpose of our research is I clarify the mechanisms of desertificatio in this region. Chinese historical source| including travelers’ diaries and the ma fests of provisions stocked by Chines garrisons, and the corresponding arche

relate with the last glacial maximum, dates to between 20,000 and 15,000 years ago and is characterized by choppers and chopping tools made from pebbles and

since we surveyed many kinds of places

other simply chipped scraping tools made

where artifacts could have been preserved,

logical record suggest that a combinati

from large flakes. These artifacts were probably made by nomadic hunting-andgathering people 1o kill and butcher game and to collect and process wild vegetables. The other prehistoric tradition we are able to identify belongs to a period of opti-

we believe the southern Tarim Basin was

of climatic deterioration and agrarian

probably used little or even abandoned during these times. Climatic changes may be partly to blame. During the late Pleistocene, for example, environmental conditions fluctuated greatly, and at times essential resources, notably water, may have become

management in the historical period con) tributed to creating the impoverished envi

mal climate, from about 7,000 to 4,000 years ago. The artifacts are dominated by microliths (exceptionally small stone tools) but include fine red, sand-tempered pottery: both are clues to a relatively recent age. Pottery is one of the defining

traits of the Neolithic period, or New Stone Age, beginning about 10,000 years ago, when human groups became more

feng. The possibility remains that further fieldwork will help fill these gaps, but

scarce. Given the localized nature of the

have grown explosively in the past century—in some cases the populations; small settlements have more than quad

make the arca inhospitable. We suspect

Basin’s future development, China's p ners may want to review both the s cesses and failures of the region’s lo forgotten prehistoric peoples.

settled and began to cultivate food. The

pottery remains may thus indicate the be-

area unattractive for those depending on

NATURAL HiSTORY 9/92

we hope our research will prove of practical benefit. Many of the oasis ments of the southern Taklimakan

‘Taklimakan’s resources and the sensitivity of arid lands in general to human overexploitation, even a sparse population of hunter-gatherers could then have helped that, first, the early nomadic hunter-gatherers overhunted the game, making the

38

ronment we see today. These observation| are helpful 10 us in trying to understa the more distant past. At the same

pled. In making decisions about the Tas

mi