摘要
湖南以碳酸盐岩沉积为主的泥盆系,有灰岩、白云岩相区(台地相)和泥灰岩、泥质灰岩相区(台盆相)之分。后者中常发育一套岩性以硅质岩、硅质灰岩、硅质页岩及泥灰岩为主的含硅质岩系。该岩系分布广,岩性稳定,且常有特殊的地貌显示,可视为“标志层”,但大化石稀少,时代依据不足,对其归属意见不一。湖南省地质局区测队在1:20万衡阳幅,城步幅将其划为中泥盆统棋梓桥组上部;赵汝旋等(1978)划归上泥盆统佘田桥组底部;湖南省地质科学研究所,湖南区测队、姜水根(1983)沿用赵汝旋等方案,将其划为上泥盆统佘田桥组底部。
A set of Devonian siliceous rock series consisting mainly of siliceous rock, Siliceous limestone and siliceous shale are developed in the marl facies distributing areas of Hunan province.We call it Ding-hechong Formation.It is found widely and unique in lithology, so the former geologists used it as a 'key bed'.Based on the study of conodonts occurred in the rock series in recent years, the author considered that the Dinghechong Formation mainly belongs to Givetian stage of Middle Devonian System in central Hunan and corresponds to Frasman stage of Upper Devonian System in southern Hunan.It is a distinctly diachronous geologic body.There is a tendency that its horizon rises gradually from central Hunan to southern Hunan, i.e., from Polygnaihus varcus zone of Middle Devonian System to Palmatolepis gigas zone of Upper Devonian System, even higher horizon.
出处
《地层学杂志》
CSCD
北大核心
1990年第2期131-135,130,共6页
Journal of Stratigraphy
