摘要
贵州东南部下寒武统发育较为完整,相变剧烈,组成总体向上变浅的沉积序列,该序列代表一个二级层序;该二级层序还可以进一步划分为5个三级层序。自北西向南东,随着从斜坡到盆地的沉积背景变化,下寒武统逐渐变薄,直至变为一个难以进行三级层序划分的凝缩作用序列。依据三级层序"空间上相序的有序性和时间上环境变化的同步性",以地层记录中"两种相变面和两种穿时性"为基本要素建立研究区下寒武统层序地层格架,该格架表明了在寒武纪早期的快速海侵所造成的台地淹没事件之后,所形成的特殊的三级沉积序列样式。
Lower Cambrian strata are quite completely developed in southeast Guizhou,and the transitional facies characterized by intense facies change comprise an upward shallowing sedimentary succession,which constitutes a second-order sequence.This second-order sequence can be further divided into five third-order sequences.From northwest to southeast,with the change of sedimentary setting from slope to basin,Lower Cambrian strata gradually thin and eventually form a condensed succession which is difficult to divide in the third-order scale.Based on two kinds of natures of the third-order sequence,i.e.,the regularity of lithofacies succession in space and the synchronism of environmental change in time,and taking the two kinds of facies-transition surface and two kinds of diachronisms in stratigraphic records as the fundamental elements in building sequence-stratigraphic framework for the Lower Cambrian strata of the study area,the authors hold that the sequence-stratigraphic framework demonstrates the special third-order sedimentary succession patterns formed after the platform drowning event caused by the rapid transgression at the early stage of Cambrian.
出处
《中国地质》
CAS
CSCD
北大核心
2011年第3期577-585,共9页
Geology in China
基金
中国石化科技工程重点项目(QZ-2005-06)资助
关键词
贵州东南部
下寒武统
层序地层格架
southeastern Guizhou Province
Lower Cambrian
sequence-stratigraphic framework
