鄂尔多斯盆地寒武纪沉积演化及天然气成藏条件分析  

Cambrian sedimentary evolution and natural gasaccumulation conditions in Ordos Basin

作　　者：陈强 李文厚[2] 李智超 张倩[2] CHEN Qiang;LI Wenhou;LI Zhichao;ZHANG Qian(School of Earth Science and Resources/School of Land Engineering,Chang’an University,Xi’an 710054,China;Department of Geology,Northwest University,Xi’an 710069,China)

机构地区：[1]长安大学地球科学与资源学院/土地工程学院,陕西西安710054 [2]西北大学地质学系,陕西西安710069

出　　处：《西北大学学报（自然科学版）》2024年第6期961-974,共14页Journal of Northwest University（Natural Science Edition）

基　　金：陕西省自然科学基础研究计划项目(2021JM-158);国家科技重大专项(2011ZX05005-004-07HZ);中央高校基本科研业务费资助项目(0009-2014G1271062)。

摘　　要：基于多年来对鄂尔多斯盆地寒武纪的研究成果,在大量野外剖面观察、钻井及岩心资料分析的基础上,对寒武纪地层划分、沉积体系类型、沉积演化特征及成藏条件进行研究。研究表明,研究区寒武系发育滨岸潮坪、碳酸盐台地、台地边缘3类沉积体系,鄂尔多斯盆地寒武纪为稳定大陆边缘陆表海沉积,由内向外表现为台内局限潮坪—台外开阔台地—台缘鲕粒滩—台前斜坡的构造古地理格局,沉积演化经历了早寒武世滨岸潮坪、中寒武世局限-开阔台地、晚寒武世局限-蒸发台地3个阶段,构成一个完整的演化旋回。研究认为,鄂尔多斯盆地寒武纪不发育深水沉积,烃源岩整体发育较差。晚寒武世—早奥陶世的怀远运动造成中央古隆起的形成,影响了晚寒武世的沉积格局,并且控制了中上寒武统的白云岩化作用及岩溶储层的发育。Based on the authors’years research on Cambrian in Ordos Basin,and combined with field profile observation and drilling data analysis in recent years,the stratigraphic division,sedimentary system types,sedimentary evolution characteristics and nature gas accumulation condition of the Cambrian were studied.The research shows that there are three types of sedimentary systems in Cambrian:coastal tidal flat,carbonate platform and platform margin,and the Cambrian of Ordos Basin is composed of epicontinental deposits on a stable continental margin.The tectonic paleogeographic pattern of the carbonate platform is represented by inner restricted tidal flat,outer open platform,marginal oolitic beach and front slope from inside to outside.And the sedimentary evolution experienced a complete evolution cycle,including Early Cambrian coastal tidal flat,Middle Cambrian restricted to open platform and Late Cambrian restricted to evaporation platform.The result suggests that the deep-water deposits are not developed in the Cambrian of Ordos Basin,and the hydrocarbon source rocks are usually poorly developed.The Huaiyuan Movement during the Late Cambrian to Early Ordovician resulted in the formation of the Central Paleouplift,which affected the sedimentary pattern of the Late Cambrian and controlled the dolomitization of the Middle-Upper Cambrian and the development of weathered crust karst reservoirs.

关 键 词：沉积体系 沉积演化 成藏条件 寒武纪 鄂尔多斯盆地 

分 类 号：P531[天文地球—古生物学与地层学]