安徽沿江地区中三叠世砾岩成因再讨论

摘要

中三叠世周冲村组砾岩作为研究金子运动存在与否的重点之一,其成因争议较大.本次研究发现安徽沿江地区该段砾岩存在多种成因,而并非前人认为的属单一的膏溶或岩溶成因.下部砾石以斜坡重力流、 膏溶、 岩溶及洞穴垮塌成因为主,上部砾石以搬运成因为主,且周冲村组沉积相与上覆黄马青组沉积相迥异,说明两者之间存在着明显的沉积转换界面.%As one of the key points on the existence of Jinzi Movement research,geologists had a bitter controversy over the breccias petrogenesis of Zhouchongcun Group in the Middle Triassic. In this study,multiple types of petrogenesis a-bout the mentioned breccias have been discovered in the area along the Yangtze River of Anhui,rather than the gypsum-cause or karst-cause which is the single one in predecessors' studies. The gravity-flow on slopes, gypsum-cause, karst-cause and cave-collapse make the major contributions of petrogenesis in the lower part breccias,and transport function is the main petrogenesis in the upper part breccias. and there have a lot of differences about the sedimentary faces between Zhouchongcun Group and Huangmaqing Group which can indicate the apparently existence of sedimentary transformation surfaces between them.