陆相湖盆三角洲—滩坝复合砂体分布模式及编图方法

发布时间：2018-05-28 00:48

本文选题：陆相湖盆 + 三角洲　；参考：《古地理学报》2016年04期

【摘要】：陆相湖盆与海洋环境不同,具有水体浅、能量弱、湖进湖退频繁等特点。综合应用高精度层序地层学和地震沉积学等关键技术,通过中国东部及中西部典型陆相湖盆的勘探实践、野外露头解剖和现代沉积考察,总结了陆相湖盆三角洲—滩坝复合砂体的分布模式,并提出了复合砂体地质编图法。研究结果表明:(1)陆相湖盆的"湖—陆过渡沉积体系"不仅发育分流河道,还发育河口坝和沿岸砂坝,这些不同时期的分流河道、河口坝和沿岸砂坝交织叠加在一起,在古代地层和现代沉积中得以保存;(2)地形平坦处,水体浅、波浪作用不强、河流作用为主,形成河道砂体;湖岸较陡处,波浪作用强,分流河道砂体被波浪改造,形成沿湖岸分布的滩坝砂体;(3)在高频湖平面变化背景下,岸线的迁移导致沉积坡折的迁移,形成了多期垂直于岸线分布的树枝状三角洲分流河道砂体,和多期平行于岸线呈带状分布的沿岸滩坝砂体相互交织的陆相湖盆三角洲—滩坝复合砂体的特殊结构;(4)复合砂体地质编图法基于传统单因素法,以复合砂体分布模式为指导,主要针对发育在水体较浅、地形平坦开阔背景下的陆相湖盆三角洲—滩坝砂体。
[Abstract]:The continental lacustrine basin is different from the marine environment and has the characteristics of shallow water, weak energy and frequent lake entry and retreat. Based on the exploration practice of typical continental lacustrine basins in eastern and western China, the field outcrop anatomy and modern sedimentary investigation are carried out through the application of key techniques such as high-precision sequence stratigraphy and seismic sedimentology. In this paper, the distribution model of the delta-beach bar composite sand body in continental lacustrine basin is summarized, and the geological mapping method of the composite sand body is put forward. The results show that the "lake-land transitional sedimentary system" in the continental lacustrine basin not only develops distributary channels, but also develops estuarine dams and coastal sandbars. These distributary channels, estuaries and coastal sandbars are intertwined and superimposed in different periods. In ancient strata and modern sediments, the topography is flat, the water body is shallow, the action of wave is not strong, the action of river is dominant, the sand body of river is formed, and the sand body of distributary channel is transformed by wave in the steeper part of lake bank, and the sand body of distributary channel is transformed by wave. In the background of high frequency lake level change, the migration of shoreline leads to the migration of sedimentary slope break, forming dendritic delta distributary channel sand body perpendicular to shoreline for many periods. The geological mapping method is based on the traditional single factor method and guided by the distribution model of the composite sand body, and the special structure of the continental lacustrine lake basin delta-beach dam composite sand body intertwined in many periods parallel to the shoreline with a zonal distribution of the beach dam sand body, is based on the traditional single factor method, and is guided by the distribution model of the composite sand body. It is mainly aimed at the delta-beach bar sand body of continental lacustrine basin with shallow water and flat and open terrain.
【作者单位】：中国石油大学(北京)地球科学学院;中国石油大学(北京)油气资源与探测国家重点实验室;
【基金】：国家自然科学基金项目(编号:41272157) 中国石油科技创新基金项目(编号:2014D-5006-0101) 中国石油大学(北京)科研基金项目(编号:2462013YJRC038;2462015YQ0108) 国家科技重大专项(编号:2011ZX05003-002)联合资助~~
【分类号】：P512.2

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