扬子地块东南缘多期构造变形及其油气意义

扬子地块的构造演化及其动力学机制约束着古生代海相油气成藏,而扬子地块东南缘的构造变形特征是理解整个扬子地块构造变形的关键所在.通过对武夷、云开和肇庆地区的构造特征研究,初步划分出扬子地块东南缘的三期重要变形①早古生代末期云开地区NW向剪切变形,武夷山地区ESE向剪切变形;②中生代早期云开、肇庆地区NE向逆冲推覆作用;③中生代晚期武夷山地区的脆性构造变形.在重新认识区内构造演化的基础上,对其动力学作了初步探讨.这些认识有助于今后中国南方碳酸盐岩含油气远景的评价.

Polyphase Deformations in Southeastern Margin of the Yangtze Block and Significance for Oil-Gas

The tectonic evolution of the Yangtze block constrains the formation of marine oil reservoirs.Deformation in the southeast margin of the Yangtze block is the key to understand the deformation of the whole Yangtze block.On the basis of a geological structure analysis,three important deformational stages have been recognized:(1) Top-to-NW shear deformation in the Yunkai area and top-to-ESE in the Wuyi area in the Early Paleozoic;(2) Top-to-NE thrust in the Yunkai and Zhaoqing area in the Early Mesozoic;(3) brittle deformation in the Wuyi area in the Late Mesozoic.The geodynamics of deformations has been discussed based on the newly recognized structural evolution.These conclusions are helpful to studying and exploration of carbonate petroliferous prospect in South China.