不规则状灰岩的成因及其岩相古地理意义

A Brief Discussion on Genesis of Irregular Limestone and Its Lithofacies Palaeogeographic Significance

碳酸盐岩作为海相沉积的重要组成部分,其产出常与一定的沉积相、事件沉积、成岩作用、古地理和构造作用相关联。以皖南石台—黟县一带寒武—奥陶系为例,共识别出瘤状泥质灰岩、干裂纹灰岩、竹叶状砾屑灰岩、条带状泥质灰岩、纹层状灰岩、透镜(豆荚)状灰岩和含灰岩透镜体钙质泥岩等7种不规则状灰岩,并分析其岩石学特征和成因差异,判断其对沉积相判断、古地理恢复和构造演化具有重要意义。

Carbonates,as an important component of marine sediments,has its output always associated with certain sedimentary facies in deposition event,including diagenesis,palaeogeography and Geological structure. Taking the Cambrian-Ordovician in the Shitai-Yixian area of southern Anhui as an example,we have identified 7 types of Irregular limestone, including nodular argillaceous limestone, dry cracked limestone, bamboo-like gravel limestone,banded argillaceous limestone,stratified limestone,lenticular（ pods） limestone and calcareous mudstone with limestone lens. Also,we have analyzed its petrological characteristics and genetic differences to determine the sedimentary facies,including restoration the paleogeography and structure evolution.