摘要
通过对原信阳群标准地层剖面的深入研究,查明该岩石—地层单位实属变形十分复杂的构造地层体。古生物资料表明,原信阳群南湾组确属中—晚泥盆世地层;而同位素定年结果则显示,原信阳群龟山组纯系前泥盆纪变质杂岩组成的构造地层体。据此,笔者认为原信阳群应解体。本文着重从岩石、构造分析入手,对新解体出的不同地质体分别就其地层涵义、构造归属作了较系统的论述,并扼要阐明各自发展演化的大地构造意义。
The original Xinyang Group should be disintegrated into two parts, i. e., theGuishan tectono--stratigraphic terrane and the Nanwan Formation. The former,consisting of an Early Paleozoic calc--alkaline volcanosedimentary sequence, includesa series of thrust--imbrication sheets tectonically emplaced in the major sutureduring the Caledonian subduction and collision orogeny. The latter is composed ofthe sediments deposited in the foreland basin of the Caledonian collisional oroge-nic belt, in which many Middle to Late Devonian microfossils, such as spores,scol-ecodents, chitinozoans and acritarchs, have been found.Thus this formation maybe correlated to the Liuling Group in the eastern Qinling orogenic belt. The aboveresults sufficiently prove that the Dabieshan--Tongboshan area is part of the Qi-nling orogenic belt and that the major suture of the belt is located along theTianshui-Danfeng-Xinyang-Shucheng line.
出处
《地质论评》
CAS
CSCD
北大核心
1992年第4期293-301,T001,共10页
Geological Review
基金
国家重点科技攻关项目-75-54-01-07"中朝准地台南缘构造岩浆演化及其与南华北含油气盆地的关系"研究成果之一
关键词
信阳群
地层
解体
泥盆世
地质意义
northern Dabie Mountaia
disintegration of the Xinyang Group
Middle--Upper Devonian series
Pre--Devonian metamorphic terrane
