摘要
鄂西秭归、长阳、巴东等地奥陶系桐梓组一段中碳酸盐台洼重力流沉积主要有４种类型：塌积角砾岩、碎屑流砾屑灰岩、颗粒流含砾砂屑灰岩、近源浊积灰岩。沉积特征和时空分布情况表明它们发生在两河口期早期海侵背景下（ＴＳＴ）。最初的岩崩塌积沉积受控于被动大陆边缘板内应力作用产生的构造事件，后来的重力流沉积旋回明显受渐进式海侵海平面升降波动的影响。台洼重力流沉积提供了早奥陶世华南被动大陆边缘向前陆盆地演变之前奏幕式事件在碳酸盐台地内的地层记录。讨论鄂西乃至上扬子区奥陶纪两河口期碳酸盐台洼重力流沉积的背景、成因、受控因素及研究意义。
Gravity current deposits of the carbonate platform subside in the first member of the Ordovician Tongzi Formation in Zigui,Changyang and Badong,western Hubei,fall into four types:(1) collapse breccia;(2)debris flow calcirudite limestone;(3)grain flow pebbly calcarenite limestone;and (4)proximal turbidity limestone The platform subside gravity current deposits furnish stratigraphic records of the precursory,episodic events of evolution from the Early Ordovician South China passive continental margin to the foreland basin in the carbonate platform It mainly discusses the setting,origin and constrains of gravity current deposits of the Ordovician Lianghekou'an carbonate platform subside in western Hubei and even in the Upper Yangtze region as well as the significance of their study
出处
《中国区域地质》
CSCD
1998年第1期61-65,共5页
Regional Geology of China
关键词
鄂西
桐梓组
碳酸盐台洼
重力流沉积
深积特征
Tongzi Formation,western Hubei,carbonate,platform subside,gravity current deposits
