摘要
新元古代是地质历史时期气候变化最为剧烈的时期之一,在全球范围内留下了多次明显的冰川活动记录。以峡东地区为代表的鄂西地区新元古界是国际研究的经典和热点。然而,峡东地区新元古代地层序列并不完整,其毗邻的神农架西部地层序列更具代表性。位于鄂西神农架西部的高桥河剖面,其南华系超覆于中元古界神农架群基底之上,从下而上依次为莲沱组、古城组、大塘坡组和南沱组,上覆震旦系陡山沱组。通过与鄂西峡东地区、长阳地区的代表性剖面的区域地层对比,发现高桥河剖面的南华纪沉积地层序列最为连续,是鄂西地区新元古代最完整和最具代表性的地层序列之一,能够作为该区域新元古代地层划分和对比的参照标准,并为研究这一重大关键地质时期的极端古气候演变提供基础材料。
The Neoproterozoic was a critical time in the history of the earth,because it was the time of the most extreme climate change that yielded numerous glacial deposits over the world.The Neoproterozoic strata in the Three Gorges area,as a representative of the regional succession of western Hubei,has being rigorously studied.However,the Neoproterozoic sequence of the Three Gorges area was incomplete,whereas the corresponding stratigraphic succession was better developed in the neighboring West Shennongjia area.Overlying the Mesoproterozoic Shennongjia Group,the Nanhuan（Crygenian）System at the Gaoqiaohe section in the West Shennongjia area,presented in this paper,is composed of the Liantuo,Gucheng,Datangpo,and Nantuo Formations in ascending order and overlaid by the Sinian（Ediacaran）Doushantuo Formation.The regional correlation with the typical Neoproterozoic stratigraphical sections from the Three Gorges and Changyang areas indicates that the Nanhuan System at the Gaoqiaohe Section is one of the most complete and continuous lithostratigraphic sequences in the western Hubei,and it can be used as a perfect reference for the regional stratigraphical division and correlation and for the study of the extreme climate change through the critical time.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2016年第6期236-245,共10页
Earth Science Frontiers
基金
中国地质调查局地质调查工作项目"神农架-雪峰山地区区域地质专项调查"(12120114066301)
关键词
南华系
地层序列
古气候变化
高桥河剖面
湖北西部
Nanhuan System
stratigraphical sequence
paleoclimate change
Gaoqiaohe section
western Hubei
