摘要
侧积交错层是砂体侧向迁移加积所形成．在辫状河道砂体中特别发育，其特点：①层系的整体形态呈板状，而细层呈“Ｓ”形弯曲，向上，向下收敛明显；②侧积交错层的某些细层内部可见次一级的前积交错层及沿塌构造；③层系厚度与沉积物粒度无关；④同一层系内各细层的厚度、成分和粒度有较大差异；⑤细层倾向垂直干区域古流向。辫状河道中侧积交错层发育原因是：横向环流的普遍存在；沉积物中富砂少泥。
Lateral accretion cross-bedding results from lateral accretion of sandbodies induced bythe lateral migration of channels and is very abundant in the braided channels. Its characteristics are: ① the overall shape of its sets is tabular, but its laminae are sigmoid, clearlyconverging both upward and downward. ② there is secondary cross-bedding or crosslaminations as well as slump structures in the inner part of some 'laminae'. ③ the setthickness has nothing to do with the grain size of the sediments. ④ the thickness, grainsize and composition of each lamination within the same set are significantly different eachother. ⑤the laminae dip is at approximate vertical angles to palaeocurrent direction. Thelateral accretion cross-beddings are very abundant in the braided channel as there are moretransverse circulation flows in it and more sand and less mud in the sediments.
出处
《石油实验地质》
CAS
CSCD
北大核心
1996年第3期298-302,共5页
Petroleum Geology & Experiment
基金
"八五"国家重点科技攻关项目
