鄂尔多斯盆地南部晚三叠世事件沉积—秦岭造山耦合分析  

Coupling research of event deposition and Qinling orogenesis of late Triassic,South Ordos basin

作　　者：刘璇[1] 桂小军[2] 丁晓琪[1,3] 张哨楠[3] 

机构地区：[1]成都理工大学能源学院,四川成都610059 [2]中国石油长庆油田分公司勘探开发研究院,陕西西安710021 [3]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500

出　　处：《东北石油大学学报》2014年第4期59-66,9,共8页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(40602012);中国博士后科学基金项目(2012M511941)

摘　　要：鄂尔多斯盆地南缘晚三叠世的湖盆充填与秦岭造山关系密切,秦岭造山对延长组沉积研究十分重要.结合露头与岩心、沉积与物源区资料,分析晚三叠世秦岭造山与事件沉积的耦合性.结果表明:(1)物源区隆升,造山带前缘快速下沉,湖平面上升,南陡北缓的不对称盆地形成;盆地南缘快速堆积的三角洲前缘沉积在重力失稳条件下向造山带前缘滑塌形成浊积岩、砂质碎屑流,频繁的地震导致大量的砂岩脉形成.(2)盆地南缘火山喷发,一方面导致生物组合发生变化;另一方面由于凝灰岩富营养组份导致湖水中生物繁盛,并最终促成优质烃源岩的形成.该研究结果对寻找烃源岩、判断沉积相、分析构造背景,以及油气勘探具有一定指导意义.South Ordos basin is the chief target of increasing resources and production,which has plenty of petroleum resources.There is intimate relationship between lacustrine basin infilling and Qinling orogenesis of late Triassic because of much event deposition and exploring achievements which are found in Yanchang formation at present,so it is a bias distortion if Qinling orogenesis is broken away from sedimentation of Yanchang formation.In order to resolve coupling problem of Qinling orogenesis and Yanchang formation sedimentary,we analyze outcrops,well cores,sedimentary area and source area.It is showed that source area uplift,orogenesis belt front subside,lake level rise and partly transgression are resulted by Qinling orogenesis of late Triassic.Slump turbidite are caused by unstable gravity from delta front in south ordos basin because of asymmetrical basin which south is steep and north is slight slope.Volcanic erupt along with Qinling orogenesis results in changing biologic groups,on the other hand,biologic groups are flourishing because of eutrophy of tuff,and finally facilitate the formation of superior source rock.The study of coupling relationship has a guiding significance when we looking for hydrocarbon source rocks,judging the sedimentary facies,determining the tectonic background and it is also useful to the exploration of oil and gas.

关 键 词：事件沉积 延长组 浊积岩 凝灰岩 鄂尔多斯盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探] P539.6[天文地球—古生物学与地层学]