金湖凹陷西斜坡阜二段湖相碳酸盐岩沉积模式研究

摘要

The recognition of carbonate origin in lake facies of the second Member of Funing Formation,the west slope of Jinhu Sag existed different vuewoaubts,so the major part of this research was the sedimentary facies of the carbonate rock.The main components of the carbonate rock were intraclast and bioclast,and other components were few ooide and crumb,the grain content of the rock were different,the content of different area were different,and the content of different formation were alike different;the matrix of the rock was micrite matrix,and cementing material of the rock was calcsparit cementing material.After the analysis of the components of carbonate rock,the conservation of fossil,the distributed law of the stratum thickness and cryptite,the conservation of fossil in the workarea was unbroken,the distributed law of the stratum thickness was obvious,the change of the stratum thickness was little;and the cryptite was distributed in all the area.So a kind sedimentary facies was established which was the carbonate terrace,the carbonate terrace was a kind of depositional system made up by the bioclastic limestone and cryptite,and it was a kind of standard carbonate formation formed in the strong-weak hydrodynamic force environment.This facies can be classified into carbonate sheet,carbonate dam,and carbonate strand and corcass.In the plane,the water was shallow in the west part of the study area,and hydrodynamic force was powerful,so the carbonate dam and strand was developed;in the east,the water was deep,and hydrodynamic force was weak,so the carbonate terrace was developed,in longitudinal direction,the carbonate formation deposited from the E1f2-32 sublayer,the fastigium of the deposition was E1f2-22 sublayer,and declined in the E1f2-12 sublayer,the deposition formed a entire carbonate sedimentary system.Finally,the sedimentary model of the carbonate rock in Lake Facies was established.%前人对金湖凹陷西斜坡地区阜宁组阜二段湖相碳酸盐岩地层的成因认识不统一,因而本次研究以该层碳酸盐岩沉积相为重点,通过对研究区碳酸盐岩的成分组成、虫管保存程度、地层厚度分布规律、泥晶灰岩等的研究,提出研究区发育一套碳酸盐岩坪沉积体系。碳酸盐岩坪是一套静水环境下的泥晶灰岩和生物碎屑灰岩为主体的沉积体系,包含碳酸盐岩席、碳酸盐岩坝、碳酸盐岩滩以及泥坪四种微相。平面上在研究区西部水体较浅,水体动力较强,发育碳酸盐岩滩、坝相,东部水体较深,水动力较弱,发育碳酸盐岩席。并在全面研究基础上提出了碳酸盐岩坪沉积体系的沉积模式。