ON THE TIBETAN PLATEAU

PETER JACKSON

THERE CAN be few Himalayan mountaineers and travellers who have not shared with romantics and mystics a fascination with Tibet. That remote high country is a looming presence from Ladakh in the west to the Abor country in the east. The ancient ties which link the southern flank of the Himalaya with Tibet are everywhere obvious, from the physiognomy of the people and their way of life to the spectacular monasteries. And there is that great white-topped concealing wall.

For centuries Tibet has been a land of mystery, visited by few outsiders, who often had to disguise themselves in order to avoid capture, which might lead to slavery or even death. Much of the earliest information came from intrepid Jesuit misssionaries. When Britain tightened its hold on India Warren Hastings sent George Bogle on a trade mission to Tibet in 1774 and he visited Gyanze (Gyantse) and Zhaxilhunbo (Tashilhunpo), seat of the Tashi or Panchen Lama. A few years later Samuel Turner followed in his footsteps. They were not geographers, but both expressed the view that the Yarlung Zangbo (Tsangpo) was the upper part of the Brahmaputra, a fact that was not finally established for another century.

During the 19th century, explorers gradually developed the map of the southern flank of the Himalaya, but Tibet remained largely unknown. It was not until 1866 that the position of Lhasa was fixed when Nain Singh, one of the most famous of the Pundit explorers, managed to smuggle himself into the city with a caravan and to stay for three months.

Not long afterwards occurred the famous incident of the logs. A Chinese lama from Darjeeling was sent into Tibet in 1880 charged with following the Yarlung Zangbo as far as possible downstream and then to throw marked logs into it, which, it was hoped, would be picked up in the Brahmaputra in India and thus prove that the rivers were the same. Four years later the lama's assistant, Kinthup, returned alone and asked for Captain H. J. Harman of the Survey of India, who had sent them to Tibet. Harman had retired and the watch for logs had been given up. The story told by the untrained and illiterate Kinthup received scant attention. Fortunately, two years later, his account was translated and it told of how the lama had sold Kinthup into slavery and then gone to China. Kinthup eventually escaped and took over the mission, following the Yarlung Zangbo right down to the Dihang gorge. He had even got within 35 miles of the Assam plains, but had had to turn back. The detail, all carried in Kinthup's head, was sufficiently impressive for Survey officials to accept it, despite the scepticism of others. Only 30 years later was it fully confirmed when Morshead and Bailey explored the gorge and found that Kinthup's details were exact.

Note: Place names have been given in their new Chinese form, known as Piny in, with the old familiar form in brackets. The Pinyin form, introduced by the Chinese Government for transliteration into Roman script, has now been generally accepted by geographical authorities in place of the earlier forms which varied in different languages.

The opportunity for the first scientific surveys came when Colonel Francis Younghusband was despatched on a mission to the Dalai Lama in Uhasa. Geologist H. R. Hayden was able to make the first contributions to knowledge of the geology of the Tibetan plateau to complement the studies being conducted along the Himalaya.

When the first Everest expedition went to Tibet in 1921 Dr A. M. Heron of the Geological Survey of India was a member, and later N. E. Odell in 1924 and L. R. Wager in 1933 added to the knowledge of the geology of southern Tibet.

As far as natural history was concerned there was very little information forthcoming until after the Younghusband expedition, but from then onwards British officials and visitors built up a picture of the situation between Sikkim and Lhasa. Apart from lists of birds there were reports of herds of wild ass, Tibetan antelope and gazelle.

The sedimentary composition and the presence of marine fossils in the Himalaya provided evidence that the mountains had been thrown up from beneath a sea. At the same time it was recognized that there must have been some connection between peninsular India, Australia and South Africa from the evidence of geology and fossil and existing fauna and flora. Although others had suggested that the world's land masses might have moved over geologic time it was the German geophysicist, Alfred Wegener, who pioneered the modern theory of continental drift which proposed that the land masses were once linked in a super-continent, which he named Pangaea. The northern part, including Eurasia and North America, he called Laurasia. The southern part, separated from the north in the central and eastern areas by the Tethys Ocean, consisted of South America, Africa, Madagascar, Antarctica, Australia and India and was named Gondwanaland after the Indian Kingdom where fossil plants common to all 300 million years ago were first described and given the name Glossopteris. They had grown in a cold climate.

Wegener theorized that the ancient land masses had broken up and drifted over the surface of the globe to their present positions. However, the major objection, which led many eminent scientists to discount the theory, was that there was no known mechanism by which such huge land masses could have been moved.

It is only within the last 25 years that the mechanism has been discovered. Oceanographers traced mid-ocean ridges from the Atlantic to the Indian and Pacific Oceans, and found that molten rock was oozing from beneath the ridge system and cooling to form fresh seabed. Core samples of sediments on the abyssal plains on either side of the ridge proved to be older as they were taken at greater distances towards the continental shelves. Furthermore studies of the palaeomagnetism locked in the rocks of the seabed showed bands parallel with the ridges conforming to past changes in the earth's magnetic field. The spreading of the seabed, which continues to form the plates on which the land rides, showed how continental drift has been powered.

No trace has been found of ancient land bridges between the former constituents of Gondwanaland, which were at one time thought to account for the existence of related fauna and flora.

While these studies were in progress Tibet had become inaccessible to westerners, and almost all outsiders, as China asserted sovereignty over the region. There were reports from time to time of Chinese .scientific activity but very little information about it.

The full extent of these studies was finally disclosed in 1980 when the Chinese Academy of Science invited leading geologists and naturalists from all over the world for a symposium on Qinghai- Xizang (Tibetan) Plateau. They were all known for their work related to the Himalaya and contributions to the new understanding of the earth's geological history. Representatives of India, Nepal, Pakistan and Bangladesh were among the group, which also included scientists from North America, Europe, Japan and Australia. The doyen was Professor Ardito Desio of the University of Milan, famous for his expeditions to K2' and his studies of the geology of the Karakoram.

Professor Liu Dong-shen, from the Chinese Institute of Geology, opened the symposium with a review of the multi- disciplinary research carried out on the Tibetan Plateau. Expeditions began in 1951-52 with studies of the geology, geography and agriculture of central and eastern parts of Tibet. In 1959 came the first expedition to Qomolungma (Chomolungma, Sagarmatha or Everest) followed by further studies during 1960-61 in central and southern Tibet. Meanwhile another series of studies from 1958 to 1981 covered the geography, agriculture and river conservancy of the eastern plateau, including the gorges. In 1964 an expedition was sent to Xishabangma (Shisha- pangma), and in 1966-68 the second expedition to Qomolungma was undertaken. A seven-year study involving over 50 disciplines and over 400 scientists in the field took place from 1973 to 1979 to study the geophysics, geology, geography, biology and agriculture of the whole of Tibet. A third expedition to Qomolungma took place in 1975 when the Tibetan woman mountaineer, Pando, reached the summit — an electrocardiogram was taken by telemetry when she was on the mountain.

Professor Liu declared that the results of the studies indicated that the east-west line of the Yarlung Zangbo was the suture line where the Indian plate, after its long movement northwards from ancient Gondwanaland, had crashed into the Eurasian plate. The Indian plate was continuing to push under the Eurasian resulting in a continuing rise of the Tibetan Plateau and the Himalaya of 10 mm a year.

Tibet is rich in fossils and Chinese scientists have discovered more than 3800 species, compared with only 300 species recorded earlier. Of special importance as evidence of the geological history of the area was the finding of fossils of Glossopteris, a primitive plant, and others of cold-water life-forms, which have also been discovered in other lands which formed part of Gondwanaland over 200 million years ago when it was far south. These fossils were all south of the Yarlung Zangbo. But north of the river the fossils include Gigantonoclea, a characteristic plant of the Cathaysian flora of the same period in eastern Asia, along with warm-water life-forms which associate the area with the former Tethys Ocean.

In between runs a 2000 km long east-west belt of ophiolites, basic and ultra-basic lavas, which formed in the basin of the Tethys and have been thrown up to a present height of about 4000 m. The belt connects with the Indus ophiolites to the west and the Burmese ophiolites in the east.

Studies of palaeomagnetism also provide evidence that the area north of the Yarlung Zangbo is part of the Eurasian plate while the south side is part of the Indian plate.

The Indian plate, which has a crust 50 km deep is still pushing northwards against the 70 km thick Eurasian plate, causing a rise of 10 mm a year, or 1000 m in the last 100,000 years.

Professor Liu said that it appeared that the Himalaya system might have been completed between the Miocene and Pliocene (10-25 million years ago), but even then the plateau might not have been more than 1000 m in elevation, judging from the discovery of fossils of three-toed horses (Hipparion) and associated fauna. But about a million years ago, at the end of the Pliocene, there appear to have been three successive massive uplifts.

During the upheaval of the plateau there were four or more separate glacial periods, and by the late Pleistocene, when the Himalaya had reached a great height, they cut off the warm wet monsoon and brought a cold arid climate in Tibet, with permafrost appearing, glaciers retreating and lakes dwindling.

Not only the climate of Tibet is affected by the Himalayan barrier. The plateau has been shown to be a heat source and heat sink, and has a monsoon of its own, which is negatively correlated with the south-west monsoon i.e. it is strong when the south-west monsoon is weak and vice-versa. Chinese scientists believe that the effects of the plateau and the Himalaya on climate may extend to the central Pacific and the southern hemisphere.

In Tibet climatic conditions become more severe from south-east to north-west. Thus in the south-east there are forests, which give way in succession to meadows, steppe and desert. The high plateau north of the Kangdese-Nianqengtanggulha range is considered best suited to yak and sheep raising, and the Yarlung-Zangbo valley suitable for cultivation of winter wheat, which grows up to 4200 m, and qingke, a huskless barley, which grows up to 4800 m. These are believed to be the highest limits in the world. The winter wheat yield goes as high as 13,000 kg/ha, one of the highest in China, thanks to the radiation intensity and the long duration of growing- temperature.

In the forest belt in the south-east dark coniferous forests grow as high as 4100-4600 m with a yield of 2000 m³/ha.

The uplift of the Himalaya and the plateau have produced a zoogeographical frontier between the Palaearctic and Oriental realms. Dr. Cheng Tso-hsin of the Institute of Zoology reported that 191 mammal species, 532 bird species, 49 reptile species, and 24 amphibian species have been collected in Tibet. They include seven new species and eleven new subspecies. The effects of climate and altitude are reflected in the fact that the small, lower Oriental zone in the south-east has 33 per cent of the mammals and 36.4 per cent of the breeding birds of the plateau, compared with the vast Palaearctic zone's 27.4 per cent of mammals and 31 per cent of breeding birds. Most of the Palaearctic species of birds are found above 3000 m and Oriental below 4000 m.

Only some of the topics of more general interest are mentioned above out of more than 300 papers presented to the Beijing symposium. The main areas covered were geophysical conditions, geological history and the origin of the formation of the Tibetan plateau; characteristics and evolution of the fauna and flora and the effects of the rise of the plateau, including the adaptation of man and animals; and the formation and differentiation of the geographic environment.

For the foreign participants it was the opportunity to travel for two weeks through southern Tibet that was most exciting, and during the flight from Chengdu to Lhasa one could not help sympathizing with the pilot who could be envisaged struggling to keep our aircraft level as his passengers surged from side to side to gaze at the panorama of mountains and the deep gorges of the Changjiang (Yangtse), Mekong, S'alween and Yarlung-Zangbo rivers. There was a distant view of the northern wall of the Himalaya and then we descended gently over the Yarlung-Zangbo valley and landed at Gongga airstrip on the south bank of the river. The runway was clearly visible on satellite photos brought by some of the American participants.

It was a two-hour drive to Lhasa over dusty but smooth roads, crossing the river by the Quxu (Chushu) bridge and following the Kyu Qu river to the fabled city. We rounded a bend and far up the valley the sun glinted on the golden roofs of the Potala. Unfortunately it was somewhat overshadowed by a row of gleaming silver oil storage tanks and a cement factory.

A three-day halt provided ample opportunity to explore Lhasa, where the Potala Palace of the Dalai Lama is the main attraction. This magnificent building dominates the valley, and the view from the roof is breath-taking in its expanse in the sparklingly clear air. At the foot of the Potala Hill the old village was little changed from the old pictures, but the old entrance gates between the feet of the Potala and Iron (Chag Do) hills were gone. On Iron Hill only jumbled ruins remained of the old Medical College, and apartment blocks were coming up at its foot.

The famous Turquoise bridge leading to old Lhasa has gone, but the town itself looks little changed. The area around has filled up with concrete buildings with corrugated iron roofs.

The Potala itself is only a museum now, but from memories of Himalayan monasteries one could repeople it with hundreds of monks amid the smell of incense and butter lamps and the clash of cymbals and the boom of horns breaking over the murmured prayers. The murals, images and hangings are in good condition, and especially splendid in the Dalai Lama's apartment. In his tiny bedroom his clock stood beside the iron bedstead where the bedding was neatly folded.

We also visited the Norbulingka, the Jewel Palace, from which the Dalai Lama escaped and fled to India in 1959. Here his bed was made up and the cover turned back for him to get back in. In the anteroom was a large radiogram bearing the Indian crest, with some old 78" records, presumably a gift in former times.

At the Jo-kang, often referred to as the Lhasa cathedral, a long queue of pious Tibetans processed past the idols and through the chapels where butter lamps flickered. Most were in traditional dress, but there were many with Chinese green caps and even some in lively tee shirts. The principal idol, the Jo, was destroyed during the Cultural Revolution and has been replaced by a replica. The original had been specially venerated because it was reputed to have been brought to Lhasa by the Chinese Princess who married King Song zan gan bu in the 8th century and, with the Nepalese Princess he married at the same time, brought Buddhism to Tibet.

On the octagonal street encircling the Jo-kang pilgrims moved clockwise spinning prayer wheels and telling their beads. Some Chinese soldiers moved against the stream, but later it was reported that they had been banned from the street so as not to give offence to Tibetan religious sentiments.

Drepung, once the world's largest Buddhist monastery with over 7000 monks, is now only a museum like the Potala, but also in good repair. It is something of a ghost town in which a few aged monks shuffle along the white-walled lanes and the deserted prayer halls.

Part of the studies by the Chinese involved the adaptation of man to the altitude of the plateau, and the foreign physiologists in our party carried out their own observations of our party, which had flown from the plains to Lhasa's 3658 m. Over half of the 55 persons sampled suffered effects from the altitude — headaches, loss of energy, insomnia, vomiting, shortness of breath, digestive problems, colds, coughs, sore throats and sore noses. But from a peak on the day after our arrival the symptoms declined steadily, although even after five days a considerable number still suffered some effects, and some individuals had to be flown back to lower altitudes.

Chinese doctors said that Tibetans had the same blood values as Jowlanders in, for example, Shanghai, but lowlanders on the plateau showed a considerable increase in haematological values, which became normal' only after 10 to 15 years. When lowlanders whose haematological values had become normal returned to the lowlands they suffered a period of one to three months of re-adjustment. The doctors said that a high percentage of lowlanders had to leave the plateau because, after a year or two, they developed chronic mountain sickness with a tremendous increase in red blood cells.

Ninety kilometres northwest of Lhasa we visited the Yangbajain geothermal field, one of 40 high temperature hydrothermal regions in the Himalaya geothermal belt. Plumes of steam rose against a background of the snow-capped Nyainqentanghlha range, and vapour rose from a thermal lake. The resource is being tapped for an experimental 1000 kw power station which is to be expanded to provide Lhasa's main power supply.

Moving out of Lhasa in Japanese mini-buses we recrossed the Yarlung-Zangbo at Quxu and climbed to the 4794 m Kamba La pass from which we gazed down on the sapphire waters of the Yamzhog Yumco (Yamdrok Tso). The Chinese have found evidence that this extensive lake once had an outlet to the Yarlung-Zangbo. Now it covers 678 km2 with a drainage area of 6100 km2. Its banks drop steeply to reach 30 m within 300 m of the bank and at its deepest it is 59 m. A species of carp Gywinocypris waddellii is common in the lake and commemorates the name of L. A. Waddell, who accompanied the Younghusband expedition and contributed much to knowledge of the Himalaya during long residence.

We skirted the northwestern end of the lake and climbed over the 5045 m Kari La pass, where great glaciers hung from the walls, and headed down the narrow valley to the Gyanze (Gyantse) plain. Alongside was the telegraph line, looking just as it does in the photographs of the time it connected Darjeeling with Lhasa.

Gyanze too was a vision from old books as I stood where the British were encamped in 1904 and looked at the fort on its pyramidal hill. Later I walked up through the ruins and was shown cartridge cases and shell fragments from the battle which raged before the fort was taken. From the fort itself there is a splendid view over the Nyang Qu valley, one of the most fertile areas of Tibet.

The view also takes in the walled monastery and pagoda of Gyanze and comparison with old pictures showed that many buildings were no longer there. The pagoda, said to be modelled on the original at Gaya where the Buddha achieved enlightenment, contains small chapels where the murals retain the richness of the original vegetable dyes, which are a pleasant contrast to the rather garish synthetic enamels used for renovation elsewhere.

Xigaze (Shigatse) is Tibet's second city and lies at the confluence of the Nyang Qu and the Yarlung-Zangbo. Here too the hill fort has been reduced to a pile of rubble. But the crowning glory of the area is the seat of the Panchen Lama, Zhaxilhunbo (Tashilhunpo), a fine complex of whitewashed buildings and narrow lanes topped by golden roofs against a steep hillside. Only a few old monks remain here too, some of whom were engaged in renovation, A few pious Tibetans were making the cir cumambulation outside the walls.

At Xigaze the Yarlung- Zangbo flows through a broad valley which is 8-10 km wide in places. There are croplands on terraces and river bars, and also extensive areas of barkhan sickle-shaped dunes built up by the powerful westerly winds. Here we found the Tibetan toad- headed lizard Phrynocephalus theobaldi, two live specimens of which were collected to become the first of their kind to reach the United States.

There is a ferry at Darzhuga leading to a road on the north bank which leads back to Lhasa by way of Yangbajain. Below the ferry is the 80' km long Toxia gorge, where the Chinese hope to make use of the total fall of 100 m to generate electricity.

One of the exciting events of the journey occurred near Xigaze where some of our party were collecting mollusc fossils from loess deposits. They found some vertebrate bones, which have since been identified as a part of nestling short-eared owls Asio flammeus with the remains of a skylark Alauda arvensis, a sparrow Passer montanus or rutilans, voles Microtus blythi and hamster Cricetulus kamensis, which must have been prey. What made the parents desert their nestlings thousands of years ago?

A few kilometres south of Xigaze one can climb on the ophiolite belt which was once the bottom of the Tethys Ocean. Distinctive pillow lavas, which form only on ocean beds, lay on the surface.

It was on the ophiolite belt that I overheard the diminutive Professor Desio say to a solicitous Chinese as he strode up a slope at nearly 400 m : 'The important thing about being 84 is not to feel 84 V

West from Xigaze was typical of much of the part of Tibet we saw. It resembled the jumbled remains of a giant layer cake with convoluted strata showing purple, pink, green, yellow and brown. In the brilliantly clear atmosphere there were immense vistas over rolling hills and snow-capped ranges. Small gangs of men and women tended the road and kept it smooth with small horse-drawn graders. Dark patches of green marked fertile lands around villages. It appears that this good land is often the result of wind-blown loess walking down hillsides to form fertile soil.

There were no mani walls, those symbols of Buddhist piety which are such a feature of trails in the Himalaya. They were destroyed after the Tibetan rebellion and in the Cultural Revolution. On the other hand some rock sculptures had been renovated and repainted.

During a halt I was able to spend some time watching a pair of ground choughs Pseudopodoces humilis. They represent the only endemic genus of birds on the plateau. Resembling large grey larks with longish down-curved bills they have a noticeable white patch on the nape and white outer feathers to the tail which they flick like a redstart. They are fairly common and may be seen flying low over the ground and perching on rocks or lumps of earth emitting a" squeaky call. They nest in the holes of pikas or mousehares (Ochotona spp), Although they are currently classified with the crow family, Br Dillon Ripley, Secretary of the Smithsonian Institution, Washington, and one of the leading specialists on birds of the Indian subcontinent, believes they may in fact be aberrant starlings.

Birdlife was not abundant, although I listed 61 species during our tour. It was disappointing not to see many bar-headed geese (Anser indicus) or Brahminy duck (Tadorna ferruginea). Earlier travellers reported that they were common and very1 tame in southern Tibet. But the few barheads we saw took off in alarm at a great distance, indicating hunting pressure. A pair of Brahminy duck were notable for having 11 young. Chinese ornithologists said that both species were still common on the central plateau, where most of the Tibetan mammals, such as yak, kiang wild ass,' antelope and gazelle, are also to be found. Our mammal sightings were restricted to two hares, two pikas and a marmot.

Kekar (Shekar) Dzong no longer exists as such. It has been renamed New Tinggri as district town. The old dzong, which climbs steeply up a mountainside, is just rubble, having been shelled during the Tibetan rebellion and the Cultural Revolution. Fragments of images were still to be found among the wreckage of the prayer hall, where a broken mural of the Buddha has bullet holes in eyes and mouth.

Near old Tinggri is the valley up which one can hope to see Chomolungma, but for us it was mid-June and heavy clouds hung over the Himalaya.

The passage from Tibet to Nepal is dramatic. The road climbs to the 52G0 m Yagru Xongla, a peneplain which is what remains of an ancient eroded mountain range. Sheep graze there on the sparse vegetation and there is a view westwards to Xixabangma (Shisha- pangma) 8012, m. The road turns south and drops away steeply into the valley of the Bo Qu, which becomes the Sun Kosi in Nepal. At 4950 m fossils of Hipparion three-toed horses have been found in a layer of white-grey sands.

Going down the valley vegetation gradually increases until it takes on the aspect of a typical high Nepalese landscape with clouds drifting among the pines on the steep mountainside- and birds calling from the lush bush. Nyalam, in a side valley, is still an important town, and then one descends further to Zham, close to Friendship Bridge and the Nepalese border.

We were accommodated in the shell of 'a new multistorey hotel designed to attract tourists across the border. Although beautifully situated, the hotel is in an area in which the atmosphere is Nepalese rather than Tibetan.

Our tour had been a fascinating glimpse of a fabled land, but geologists and natural scientists joined in expressing alarm to their Chinese hosts about the signs of damage to the frail ecology, of this high altitude arid zone. Signs of over-grazing were to be seen everywhere, and we frequently saw people with loads of bushes dragged from the ground by their roots, thus exposing soil to erosion. Galley in g was widespread and the many big alluvial fans were dissected, Occasional torrential rains undoubtedly cause some damage, but much is due to the stripping of vegetation by deforestation and over-grazing. Villages are often sited in the middle of the fans, probably because of easy access to water, but the possibility of a devastating flood, which may occur once in 50 years, sweeping them away and causing havoc with rock and mudflows is obvious.

The foreign experts- warned of the need for caution in agricultural expansion and development because of the fragile soils and changing weather patterns, which could lead to bad harvests and famine. The Chinese participants agreed that there should be collaborative research, making use of advances in the United States and other western countries in prediction of climatic and mountain hazards, to pinpoint dangerous trends and to help decision-makers to improve planning to maintain the ecological balance and improve the welfare of the people.

In closing one must pay tribute' to the formidable organization of our Chinese hosts, which enabled a mini-army of nearly 250' persons, including over 60 foreign visitors, Chinese scientists, cooks, drivers, etc. to travel in comfort over 1000 km on the roof of the world. Ample supplies of food and beer, and all the necessary crockery, cutlery and other items, had been flown in and moved ' with our convoy. Small groups were taken to sites covering their special interests, and there was time and help to go sight-seeing. Medical facilities included big bags of oxygen, which travelled with us in our Japanese mini-buses, which had taken a week driving from Chengdu in Sichuan over the tortuous roads of the gorge country to reach Lhasa. Accommodation in barracks in Lhasa, Xigaze and New Tinggri (Xekar) was simple but adequate. Even at Zham, where the new hotel was not ready as had been planned, plastic curtains, boards and other devices were made use of to make it habitable. Soon after arrival I slithered down a muddy path to the temporary outside drop toilet. An hour later stone slabs were already in place to make the trip less of a hazardous expedition.

Bibliography

Proceedings of the Symposium on Qinghai-Xizang (Tibet) Plateau — Astracts (1980).

A Scientific Guidebook to South Xizang (Tibet) — prepared for the excursion after the symposium.

Both the above publications are available for US $26 from the China Publications Centre, P.O. Box 399, Beijing, China.

 

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