湖南二叠系的“南、北型”问题──兼谈上、下二叠统的界线

湖南二叠系“南、北型”是由早二叠世晚期华南东吴运动主幕所造成的,在华南各省具有普遍意义．湖南的当冲组仅相当于茅口组的中下部,龙潭煤系下段则相当于茅口组的上部,因而湖南二叠系的“南、北型”实质上是一个同时异相沉积的问题．上、下二叠统界线应划在龙潭组中、下老山段之间,这个界线才是与国际上流行的界线相一致的．

The "South and North Type" of the Permian Series in Hunan Province of China and Upper Permian-Lower Persian Boundary in addition

The "South and North Type" of the Permian Series in Hunan Province was originated by the main episode of the Dongwu Movement at the later stage of Early Permian and is an event of universal significance in South China'In Hunan province,Dangchong Formation closely matches the lower and middle parts of Maokou Formation while Longtan Formation matches well the upper part of Maokou Formation. Therefore, the auther holds that it is essentially a problem of simultaneous sedimentation with different faces, that the Upper Permian-Lower Permian boundary should be placed at the base of Middle Laoshan Member of Longtan Formation. Such a boundary should be identical with the prevalent one of the world.