METAMORPHIC CORE COMPLEXES IN THE WESTERN MARGIN OF THE YANGTZE CRATON

摘要

More than 14 distinctive isolated domelike metamorphic terranes scatter along a narrow belt from the Backmountain of Longmenshan southwestward to the west of Kangdian crystalline axis along the western margin of the Yangtze craton, Sichuan province (Fig. 1). They are the Motianling, Qiaoziding and Xuelongbao metamorphic core complexes (MCC) in the north, Gongchai Gezong and Yaside MCC in the middle, and Jianglang, Qiasi Changqiang and Taka MCC etc. in the south. From the tectonic setting of view they were located in the centre part of the miogeocline of the continental shelf in the western margin of the Yangtze craton during Paleozoic stage, after deformation they are located in the hinterland west of the Longmenshan and Yanyuan foreland thrust zone which thrust onto the foreland basin southeastward and south- southeastward respectively.