贵州东部中新元古代沉积旋回的划分

Classification of the Cycle Sedimentation of Mesoproterozoic and Neoproteroxoic Era in Eastern Guizhou

应用层序地层学及事件地层学的概念和方法 ,从沉积旋回的研究入手 ,首次在该区出露的中、新元古代地层中划分出 4个不同级别的旋回层 (或层序 ) ,即 (从老到新 )梵净山群 1个 (相当于 1个一级层序 )、下江群 1个 (相当于 1个一级层序 )、震旦系 2个 (即铁丝坳组—大塘坡组和南沱组—灯影组 ,相当于 2个二级层序 )。同时对上述所划层序的层序界面、初始海泛面、凝缩层 (其中包含最大海泛面 )及沉积体系域的特征作了归纳性描述。另外还分析讨论了层序的形成时限、级别及其与海平面变化之间的关系。最后还从层序地层学角度重新厘定和优化了甲路组 \乌叶组界线。

With the application of concept and method of programme stratigraphy and event stratigraphy,starting with the research for the cycle sediment,where the cyclothem of sequence of the outcropping stratum of mesoproteroxoic and neoproteroxoic era grade may be classificated into four different grade there occur from old to new one in Fangjinshan monutain group,one in Xiajiang group the same as one first stratum,and two in Sinian system involving Tiensiao_Datangpo group and Nantuo_Dengying group being equivalent with two second grade Meanwhile the feature of stratum interfaces,initial marine_flooding surface,condensed section containing the largest marine_flooding surface and sedimentary system is made a conclusive description Moreover,the developping period of sequence and grade and relationship with changes of marine surface are analyzed Finally,from the angle of sequence stratigraphy,Jialu group and Wuye group limit is drew up and optimalized again