Sixty years of the First Scientific Expedition to the Shisha Pangma
On May 2,1964,10 members of the Chinese Mountaineering Team successfully arrived at the summit of Mount Shisha Pangma,one of the fourteen highest peaks in the world with an altitude of 8027 meters.During the period of mountaineering,a scientific expedition was organized by the Chinese Academy of Sciences to thoroughly investigate the geology,geomorphology,topography,glaciology and ecology of the mountain area,since the Shisha Pangma is a peak entirely located within China's territory.In terms of geology,the main achievements obtained during this expedition include:(1)classifying the metamorphic rocks in the region as Shisha Pangma Group,which can be subsequently sub-divided into the gneiss unit at lower and the schist unit at upper levels.The above two rock assemblages are comparable to the presently formulated Higher Himalayan crystallines(high-grade metamorphosed)and the Rouqiecun Group(low-grade metamorphosed)in the neighboring areas.The gneiss unit can be further divided into the lower coarse-grained gneiss,including the granitic gneiss with potassium-feldspar phenocryst,and upper fine-grained leptynlite.It was also concluded that the peak is composed of the above-mentioned leptynlite,a kind of fine-grained gneiss;(2)established a Phanerozoic stratigraphic column in the area,including the Upper Paleozoic Gangmenqiong Group,the Mesozoic Tulong Group and Xuela Group,and the Cenozoic Yambughangala Group;(3)discovering a kind of plant fossil of Quercus Semicarpifolia,from the pebbly sandstone of the Lower Yambughangala Group,at the campsite of 5800 meters.It was subsequently proposed that the Himalayas have been uplifted by about 3000 meters during the past 3 Ma since it was suggested that this flora lived in the Late Pliocene with a much lower altitude of～2500 meter;(4)obtaining a K-Ar age of 13～15Ma for the leucogranite and pegmatite,whereas that of the augen gneiss is 19～35Ma,indicating that the Shisha Pangma was probably formed in the Miocene.The Shisha Pangma expedition and the obtained achievements played an exemplary role in the subsequent explorations to other areas of the Himalayas in China.However,few geologists have conducted any scientific investigation and study on this peak since the last climbing 60 years ago.It has been well established,by investigations to Mount Qomolangma and other peaks during the past 30 years,that the Himalaya is composed of high-grade metamorphic Higher Himalayan rocks in the lower and un-metamorphic Tethyan Himalayan sedimentary rocks in the upper parts.Between the above two rock assemblages,a deformed complex was developed by ductile extensional faulting,i.e.,the South Tibetan Detachment System(STDS).Therefore,many works are needed to be done in the near future around the Shisha Pangma,to better understand the evolution of the Himalayas,including examinations of the metamorphosed rock assemblage,Phanerozoic stratigraphic sequence,and regional structural extension.It is also important to confirm that the peak is composed of fine-grained leptynlite proposed by the previous expedition or leucogranite proposed by later investigation of foreign scientist.Meanwhile,the exact age determination of the flora Quercus Semicarpifolia is necessary,and the deposition mechanism of the Yambughangala Group sediments at high altitude needs to be better understood.
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