昆仑山区综合科学考察的新进展

中国科学院青藏高原综合科学考察队,在总结1987年喀喇昆仑山-西昆仑山综合科学考察成果的基础上,于1988年6—9月,又考察了西昆仑山东部地区、中昆仑山区。通过考察,在高原的形成、演化,自然环境变迁,生物区系的种类组成、起源、演化,自然地域的分异规律及发展趋势等方面,取得了重要证据和新进展。

RECENT PROGRESSES OF THE INTEGRATED SCIENTIFIC EXPEDITION TO THE KUNLUN MOUNTAINS

The field research work, sponsored and organized by the Integrated Scientific Expedition to Qinghai-Xizang Plateau,Chinese Academy of Sciences, was carried out in the region of western and middle Kunlun Mountains. It has made progresses concerned with following topics- formation and evolution of the Plateau; changes of the natural environment; origin of the biota; physico-geographical regional differentiation, etc.Two tectonic boundaries, their positions and features have been investigated and confirmed. The stratigraphic system and division as well as pale-ogeographic biota are established and improved in the Kunlun Region. The characteristics of volcanic activities and its relantioship with formation of the Plateau since the Tertiary are found and explained.Based on the evidence of plant fossils,loess depositions, etc. it comes to the conclusion that the intense uplifting of middle Kunlun Mountains began at the end of the Pliocene to the Early Quaternary. During the Late Pleistocene the Plateau had been uplifting nearly by the present elevation, the climate characterized by tendency of desiccation in the middle Kunlun and the Tarim Basin, with a small area of the existing glaciers in high mountains.The biota is characterized by simplified and rare species with large populations. Most of the biota, both fauna and flora, beloug to the Tibetan elements. The study area located on the south of the Kunlun and the Altun Mountains may be demarcated to the Qinghai-Xizang Region.The following 4 structure-type groups of the altitudinal belt may be identified in the Kunlun Mountains, they are extremely arid, arid, high-cold ari and high-cold semiarid,The characteristic of regional differentiations has been discussed. There is a cold-arid core area, with an elevatiou of 4800-5200m, located in the interrior of the Kunlun Mountains.