层序底界面的物质表现形式--以中国南方海相震旦系-中三叠统为例

众所周知,在层序地层学研究中最关键的是层序划分,而层序划分的关键是有关界面的识别,可用于确定层序的界面包括层序的底界面,初始海泛面和最大海泛面,其中最为重要的是层序底界面的识别,这是层序划分的基础和前提。以中国南方海相震旦系-中三叠统为例,在大量野外剖面详细观测的基础上,识别出了层序底界面的物质表现形式有 9种类型,它们分别是:①古风化壳,②渣状层,③河流回春作用面,④古喀斯特作用面,⑤斜坡重力流冲刷侵蚀面,⑥盆地内浊流侵蚀面,⑦火山事件作用面,⑧岩性、岩相转换面,⑨上超面。详细讨论了各类型界面的特征,这对于正确识别和划分层序具有重要的意义

The Apparent Types of Sequence Bottom Boundary Surface--Taking marine Sinian System to Middle Triassic Series in South China as an example

It is well known that the key of research on sequence stratigraphy is sequence division, but first of all the key of sequence division is identification of boundary surface. The boundary surface of defined sequence included sequence bottom boundary surface first trangressive surface and maximum marine flooding surface. Among them, the most important is bottom boundary surface indentification because it is sequence division foundation. The paper, taking marine Sinian system to Middle Triassic Series in south China as an example, through anlyses of filed geologic sections, identified nine types sequence bottom boundary surfaces which are :(1) weathering crust; (2) Paleosol; (3) Erosion surface of river rejuvenation; (4) Action surface of ancient karst; (5) Washing erosion surface of gravity flow on slop; (6) Erosion surface of turbidity flow in basin; (7) Action surface of volcano event ; (8) Transition surface of rock character and facies; (9) onlap surface. Research features of above boundary surfaces in detail is very important for sequence division.