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川滇藏交界区属三江印支造山带中段 ,地质构造十分复杂。文章据最近获得的岩石化学及野外调查资料分析了该区古特提斯活动大陆边缘的两套弧火山岩的特征 ,结果表明 :早二叠世的吉东龙组是碧土洋盆向东俯冲的记录 ,当时的活动大陆边缘属西太平洋岛弧型 ;晚二叠 -早三叠世的夏牙村组 -马拉松多组是金沙江洋盆 (南段 )向西消减的证据 ,当时的活动大陆边缘接近安第斯型。在此基础上讨论它们在恢复古特提斯演化的时空制约中的意义。
Sichuan-Yunnan-Tibet border area is the middle part of the Sanjian-Indo-orogenic belt, and the geological structure is very complicated. According to the recent petrochemical and field survey data, the characteristics of two sets of arc volcanic rocks along the continental margin of the ancient Tethys activity in the area are analyzed. The results show that the Early Permian Jidonglong Formation is a subduction of the Bituo-Ocean basin to the east The Late Permian-Early Triassic Xialuamu-Marathon multi-sets were evidence of westward descending of the Jinshajiang Oceanic (southern segment). At that time, the events of that time belonged to the western Pacific island arc. The edge of the continent is close to the Andean. On this basis, we discuss their significance in restoring the space-time constraints of the evolution of the ancient Tethys.