孤北洼陷西部陡坡带沙一段混积螺滩沉积特征  

Sedimentary Characteristics of Mixed Snail-shell Beach of Es_1 Formation in the West of Gubei Sag

作　　者：王冠民[1] 廖黔渝[1] 高亮[1] 

机构地区：[1]中国石油大学(华东)地球资源与信息学院,山东青岛266555

出　　处：《石油天然气学报》2009年第4期28-30,共3页Journal of Oil and Gas Technology

基　　金：山东省自然科学基金项目(Y2007E11)

摘　　要：沾化凹陷的孤北洼陷西部埕东断裂带下降盘,在沙一段中发育以螺为主的生物碎屑与陆源粗碎屑的混合沉积,厚达几十米。岩石中的螺壳大多相对完整且内部中空,镜下观察可见螺壳及砾石表面有叠层藻发育,表明这些混合沉积并非属于重力流性质,而是属于浅水的混合浅滩沉积。沉积相平面分析研究表明,这种混合浅滩主要分布在近岸水下扇体之间的湖岸地带。在近岸水下扇进积期,该带一定程度上受洪水的影响;间歇期,湖浪则将附近形成的大量螺壳搬运过来,形成与陆源碎屑的混合沉积。Mixed sediments were found out in Es1 downdip block of Chengdong fault,Zhanhua sag,where sediments the mixtures of shell-based bio-clastics and gravel-based terrigenous clastics were developed.It was tens of meters thick.Most of shells were relatively complete and hollow in rocks.Microscopic observation shows that the surface of shells and gravels develop laminated algal.Itindicates that these mixed sediments are not the nature of gravity flow and should be mixture deposition on shallow shoal.Associating study of plane distribution of sedimentary facies shows the shallow shoal is between the two near-shore sub-marine fans.It may be affected by flood in the progradation period of nearshore sub-marine fans.But,in the intermittent period,a lot of shells formed near it are removed to the shallow shoal by lake waves and formed mixed sedimentary with terrigenous clastics.

关 键 词：沾化凹陷 混积螺滩 近岸水下扇 沉积特征 

分 类 号：P618.13[天文地球—矿床学]