TECTONIC EVOLUTION OF THE GARZE—LITANG PLATE JUNCTION, WITH PARTICULAR REFERENCE TO THE GOLD DEPOSITS

摘要

Garez—Litang plate junction lies in the eastern margin of the Nujiang—Lancangjiang—Jinshajiang area, NW|trendingly and antisigmoidally extending for more than 800km from Zhidoi ,Qinghai through Garze and Litang to Muli ,Sichuan ,with a width of 5～35km .The junction is located in the arcuate turning part of the Alpine—Himalayan—Indosinian Tethyan tectonic domain ,which lies in the structural transition position between the Yangtze plate and the Yidun area . The plate junction represents an important tectonic belt ,which is a composed of a gold mineralization belt in the east Tethyan tectonic domain.(1) Garze—Litang plate junction may be divided into the following structural units:ductile shear zone and fracture system, Paleozoic nappes ,ophiolite |tectonic blocks,flysch formation in passive continental margin (Triassic Xikang group ),forearc sedimentary formation in active margin (Triassic Yidun group),and such boundary geological bodies as granitoids ,faulted basins and Tertiary nappes.