滇西中新生代锡矿带与大地构造演化的关系

滇西中新生代锡矿带属于中新特提斯成矿带的组成部分,位于海陆壳俯冲带陆壳仰冲一侧,与造山花岗岩带密切相关。根据中新生代板块活动的主要事件,可分为四个成矿期。由东往西锡矿化世代依次变新,与板块活动事件逐次推迟相关联。在一定程度上,锡矿化不依赖于围岩,主要依附于陆壳仰冲侧造山花岗岩带。雅鲁藏布江缝合带与龙木错—双湖—丁青—北澜沧江—柯街—孟定缝合带之间的区域是我国西南寻找中新生代锡矿床最佳远景区域,其中主要探索对象是晚三叠世至早始新世造山花岗岩带和与造山花岗岩带相联系的地质体。

RELATION BETWEEN THE MESO-CENOZOIC TIN ORE BELT AND THE TECTONICS OF WEST YUNNAN,CHINA

The Meso-Cenozoic tin ore belt of west Yunnan belongs to a constitu-ent part of the metallogenetic belt of the Meso-Cenozoic Tethys. It isdistributed along the continental crust obduction side of the oceanic-conti-nental crust subduction zones and closely related with the orogenic belts.According to main events of Meso-Cenozoic plate action, four metallogene-tic periods of the tin ore belt are recognized. Tin mineralized generationsbecome new in turn from east to west, which is related with successivepostponement of plate action events. On the other hand, the phenomenonis probably related with enlargement of subduction angles as time goes on.The tin mineralization dies not depend on wall rocks in a certain extent,butchiefly relies on orogenic granitic belts of the obduction side of the continental crust. The region between the Yarlung Zangbo River and Longmucuo-Shuanghu-Dingqing-north Lancangjiang-Kejie-Mengding sutures is the bestoutlook region to seek tin ore deposits in Southwest China, where the mainobjects of investigation are the orogenic granitic belts and geologic bodiesrelated with orogenic granitic belts from Late Triassic to Early Eocene.