沙滩子高弯曲流点坝沉积特征  

SEDIMENTARY CHARACTERISTICS OF HIGH-CURVED MEANDER POINT BAR IN SHATANZI AREA

作　　者：曹跃华[1] 张春生[1] 刘忠保[1] 赖志云[1] 

机构地区：[1]江汉石油学院

出　　处：《石油与天然气地质》1995年第2期184-189,共6页Oil & Gas Geology

基　　金：中国石油天然气总公司资助

摘　　要：沙滩子高弯曲流点坝的不同部位具不同的粒度特点，Ⅰ类代表下点坝及上点坝卷形脊粒度分布，Ⅱ类代表上点坝粒度分布，Ⅲ类代表串沟坝粒度分布的特点。大型交错层理是其主要的沉积构造，由下向上规模减小，并过渡为沙纹层理和水平层理，具下粗上细的粒序及二元沉积构造。在１３种岩石相类型中归纳出砂泥突变式，卷形脊、上点坝、卷形槽、串沟坝及下点坝６种岩石相组合。以发育多期卷形存与卷形槽组成的岗状地貌和深切的串沟坝的建筑结构为特征。Defferent parts of high-curved meander point bar in Shatanzi area have different grain size.type-Ⅰ represents the grain size of reeled crest distributed in upper and lower point bars;type-Ⅱ shows the grain size distributed in upper point bars;type-Ⅲ shows that of bars with trenches. The main sedimentary structure of the study area is cross-bedding, and the scale of it decreased in ascending order and it transforms into sand ripple or horizental bedding.This Kind of sediments is characterized by coarts grains in upper parts but fine grains in lower parts,and have binary sedimentary stucture. Within 13 kinds of lithofaces,6 lithofacies assemblages could be classified suchas sand-mud mutated, reeled crest,upper point bar,reeled trough,bar with trenches and lower point bar lithofacies assemblages.The mound landform that is composed of multi-reeled crests and troughs,and the bars with deep-cut trenches is well developed.

关 键 词：曲流河 点坝 粒度特征 沉积构造 水力作用 

分 类 号：P512.22[天文地球—地质学]