摘要
宜昌莲沱王家坪地区早寒武世沉积了以黑色炭质页岩夹灰岩、细碎屑岩、石灰岩、白云岩等为主的岩性组,反映了中扬子区岩性四分的特点。根据对野外剖面、显微分析和地层对比等资料的综合分析,下寒武统主要发育台地、台地边缘和斜坡—盆地三种沉积体系,并可进一步划分为5种相和10种亚相。早寒武世早期遭受了短暂而快速的海进之后,依次经历了盆地、陆棚、缓坡、开阔台地、局限台地等沉积环境的缓慢演化,显示了有规律的海退序列。研究区从水井沱期和石牌期的初期淹没型台地发展到天河板早期的缓坡型台地,海平面进一步下降,天河板中期以后镶嵌陆架型台地的格局基本确立。
The lithology group deposited in the Early Cambrian in Wangjiaping region, Liantuo County, Yichang City, is composed of black shales interbeded with limestones, fine clastic rocks, limestones and dolostones, which reflects the characteristics of four types of lithology in middle Yangtze area. Based on the comprehensive analysis of data such as field section, microanalysis and stratigraphic correlation, three sedimentary systems were developed in lower Cambrian, including plateau, platform edge and slope - basin, and can be subdivided into five facies and ten sub -facies. After the short and rapid transgression, the sedimentary of the early stage of Early Cambrian experi- enced slow evolution from margin basin, continental sheff, gentle slope, open platform to restricted platform, and indicated a regularly regressive sequence. The study area is developed from submerged platform in Shuijintuo stage and early Shipai stage to gentle slope stage platform in early Tianheban stage, mosaic sheff platform is determined after Tianheban middle stage, showing a sea level drop process.
出处
《吐哈油气》
2009年第3期211-215,共5页
Tuha Oil & Gas
关键词
寒武统
沉积相
镶嵌陆架型台地
lower Cambrian
sedimentary facies
mosaic shelf platform
