下扬子区中—新生代变格构造运动

Mesozoic and Cenozoic diktyogenese in the Lower Yangtze region

丁道桂 李凤丽

DING Daogui LI Fengli

中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China

下扬子区在中、晚三叠世—早、中侏罗世，晚侏罗世—早白垩世和晚白垩世―第三纪时期，发生了以特提斯洋与太平洋板块联合作用所导致的3期变格构造运动。一方面极大地使下扬子区古生代盆地发生了基底拆离式递进变形改造；另一方面又在下扬子区形成了上三叠统―中、下侏罗统的前渊盆地，以及由大型断裂带的平移走滑构造所形成的上侏罗统—下白垩统火山碎屑岩拉分盆地，呈“多米诺式”排列的上白垩统—第三系半地堑盆地则是岩石圈伸展拆离构造所形成的拉张盆地。3期变格运动促使了油气的形成与再分配聚集。

Three stages of metamorphic tectonic movements took place in the Lower Yangtze region due to the joint action of the Tethys and the Pacific plates from the Middle/Late Triassic to the Early/Middle Jurassic, the Late Jurassic to the Early Cretaceous, and the Late Cretaceous to the Tertiary. They made the Paleozoic basin basements undergo detachable progressive deformations, and formed foredeep basins in the Upper Triassic and Middle/Lower Jurassic. The translational strike-slip of a large-scale fault zone formed pyroclastic pull-apart basins in the Upper Jurassic-Lower Cretaceous. The Upper Cretaceous-Tertiary semi-graben basins, which are arranged in a domino style, are extensional basins formed by lithospheric extension and detachment structures. The three transformations promoted the formation, accumulation and redistribution of oil and gas.

https://doi.org/10.11781/sysydz202005687