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早—中元古代,上扬子陆块西南缘发育有河口群—大红山群、东川群、昆阳群—会理群为代表的3套浅变质火山-沉积岩系。已有的岩石学、地球化学、年代同位素数据指示了其大地构造格架及其演化史。在早—中元古代地层所夹的火山岩中,获得了4组SHRIMP U-Pb岩浆锆石年龄:1800～1600Ma、1600～1300Ma、1300～1100Ma、1100～1000Ma。结合沉积相、常量、微量、稀土元素地球化学分析,证明了上扬子陆块西南缘在早—中元古代也相应历经了4个演化阶段。1800～1600Ma,在大红山地区、河口地区、东川汤丹地区形成近东西向的裂谷盆地。1600～1300Ma,在东川因民地区表现为一被动陆缘下的伸张环境。1300～1100Ma,在菜籽园—麻塘地区为板内裂谷-洋盆,老武山地区为裂谷盆地。1100～1000Ma阶段,菜籽园-麻塘裂谷-洋盆向北俯冲或向北向南双向俯冲,在北边的天宝山地区和南边的富良棚地区形成火山岛弧,同时在扬子西缘也出现了1.0Ga左右(1007±14～1014±8Ma)的同造山或同碰撞型花岗岩,表明此时康滇地区已经拼贴到一起,并与整个上扬子陆块Rodinia超大陆形成同步。
In the early-Mesoproterozoic, three sets of epithermal volcanic-sedimentary rock series represented by the Hekou Group-Dahongshan Group, Dongchuan Group, Kunyang Group-Huili Group developed in the southwestern margin of the Upper Yangtze block. The existing petrology, geochemistry, age isotope data indicate its tectonic framework and its evolution history. Four sets of SHRIMP U-Pb magmatic zircons were obtained from volcanic rocks sandwiched by early-Mesoproterozoic strata: 1800 ~ 1600Ma, 1600 ~ 1300Ma, 1300 ~ 1100Ma and 1100 ~ 1000Ma. Combined with sedimentary facies, constants, trace elements, and REE geochemical analyzes, it is proved that the southwestern margin of the Upper Yangtze block also experienced four evolutionary stages in the Early-Mesoproterozoic. 1800 ~ 1600Ma. In the Dahongshan area, estuary area and Dongchuan-Tangdan area, a nearly east-west rift basin is formed. 1600 ~ 1300Ma, in Dongchuan Yinmin area as a passive environment under the extension of the environment. 1300 ~ 1100Ma, in the rapeseed - Ma Tong area for intraplate rift - ocean basin, LaoWu Mountain area for the rift basin. 1100 ~ 1000Ma stage, the rapeseed - Matang rift - oceanic basin subducted northward or diverted northward and southward to form a volcanic island arc in the Tianbaoshan area in the north and Fu Liangpeng area in the south, and also appeared in the western margin of the Yangtze The orogenic or collisional granites around 1.0Ga (1007 ± 14 ~ 1014 ± 8Ma) indicate that the Kang’Dian area was now collapsed and synchronized with the entire Rodinia supercontinent of the upper Yangtze block.