1. Institute of Geology, Chinese Academy of Sciences, Beijing 100029; 2. Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002; 3. Universite Blaise Pascal Clermont-Ferrand France; 4. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037
Since 1987, totally four integrated geological investigation profiles across the West Kunlun Mountains were performed. They are: (1)Profile along the Sino-Pakistan highway (from Kashigar to Kunjirap Pass); (2)Profile along the XinjiangXizang highway .(from Yecheng to Shiquanhe); (3) Pulu Village, Yutian CountySubaxi-Liuhuang Pass profile, and(4) Mangnai Town, Qinghai-Qimantaga-Muzhtaga peak profile. In the investigation region, in the northern part of the West Kunlun Mountains calc-alkaline plutonic rocks are exposed. Systematical geochronological studies of the plutonic rocks have been done, in the paper 5 U-Pb dating on the zircons,3 Ar-Ar dating on the honblende and biotites and 5 Rb-Sr dating on the wholerocks and minerals from the plutons are reported. These results enabled us to find an early Paleozoic (384-480Ma) tectono-magmatic belt, extending for a thousandof kilometers. It was formed on an active continental margin or in a postcollisional tectonis envionment, and is accompanied with a complex belonging to ophiolite suit in Kudi, Subaxi and Oy ag area. It is a newly found and defined suture zonein the interior of the Qinghai-Xizang Plateau.