试论江南造山带西南段构造演化——以黔东及邻区为例

Initiative Discussion on Tectonic Evolution of Southwest Segment of Jiangnan Orogenic Belt: Taking an Example from East Guizhou and the Adjacent Areas

江南造山带西南段,黔东及邻区,位于扬子陆块与华南陆块的过渡区,发育中、新元古代至新生代地层和多种类型的岩浆岩、变质岩,存在多期次构造运动,可划分出洋陆转换阶段的武陵构造旋回期、加里东构造旋回期和板内活动阶段的海西—燕山构造旋回期、喜马拉雅构造旋回期。具有从洋陆转换阶段的B型俯冲造山向板内活动阶段的A型俯冲造山演化、从活动型地壳向稳定型地壳的演化历程,是一个由不同时期、不同性质的造山作用构成的复合造山带,反映出扬子陆块向东南增生及江南造山带向东南迁移的演化历史。

The southwest segment of Jiangnan orogenic belt in east Guizhou and its adjacent areas is located in the transitional zone between Yangtze and south China continental blocks. In this region, strata and diverse magmatic and metamorphic rocks of Meso - and Neoproterozoic to Cenozoic Eras developed ： multiphases of tectonic movements happened; different structural cyclic phases can be divided, these include Wulingian and Caledonian structural cyclic phases during ocean - continent conversion stage, Hercynian - Yanshan and Himalayan structural cyclic phases during the stage of intraplate tectonic activities. Possessing Btype subduction orogeny during the ocean - continent conversion stage and A - type subduction orogeny during the stage of intraplate tectonic activities, and displaying the evolution course of active crust to stable one, and the history of accreting and migrating southeastward of Yangtze continental block and Jiangnan orogenic belt itself, it is a compound orogenic belt created by orogenies of multi - phases and various characters.