四川盆地东部侏罗系凉高山组层序结构、沉积演化及其主控因素  

Sequence structure,sedimentary evolution and their controlling factors of the Jurassic Lianggaoshan Formation in the East Sichuan Basin,SW China

作　　者：成大伟 张志杰[1,2] 洪海涛 张少敏 秦春雨 袁选俊 张斌[1,2] 周川闽 邓庆杰[5] CHENG Dawei;ZHANG Zhijie;HONG Haitao;ZHANG Shaomin;QIN Chunyu;YUAN Xuanjun;ZHANG Bin;ZHOU Chuanmin;DENG Qingjie(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;PetroChina Key Laboratory of Oil&Gas Reservoir,Beijing 100083,China;PetroChina Southwest Oil and Gas Field Company,Chengdu 610041,China;Research Institute of Exploration and Development,PetroChina Southwest Oilfield Company,Chengdu 610041,China;Yangtze University,Wuhan 430100,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油油气储层重点实验室,北京100083 [3]中国石油西南油气田公司,成都610041 [4]中国石油西南油气田公司勘探开发研究院,成都610041 [5]长江大学,武汉430100

出　　处：《石油勘探与开发》2023年第2期262-272,共11页Petroleum Exploration and Development

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目“岩性地层油气藏成藏规律与关键技术研究”(2021DJ04);中国石油天然气股份有限公司科学研究与技术开发项目“中西部重点盆地源-汇系统分析与沉积过程正演模拟技术研究”(2021DJ0401)。

摘　　要：综合利用野外露头、地震、薄片、重矿物组合、碎屑锆石U-Pb定年等资料,研究四川盆地东部(简称川东地区)中侏罗统凉高山组沉积特征、湖平面升降变化、物源性质,进而探讨周围造山带的构造作用对沉积体系的控制作用。研究表明:凉高山组主要发育三角洲—湖泊沉积体系,包含了一个完整的三级层序,进一步可划分为4次湖平面的升降旋回(四级层序),其中旋回Ⅰ和旋回Ⅱ湖盆主要分布在川东地区,旋回Ⅲ和Ⅳ湖盆迁移至四川盆地中部地区,使得川东地区南北沉积特征差异性明显。物源分析结果表明,川东地区凉高山组存在3种类型物源,其中Ⅰ类物源母岩主要以酸性火成岩为主,主要来自近源的扬子板块北缘;Ⅱ类物源母岩主要为中酸性火成岩和变质岩,物源区主要在南、北秦岭中部;Ⅲ类物源母岩以变质岩为主,中—酸性火成岩次之,物源主要来自北大巴山地区。综合研究沉积体系和物源性质的变化,认为川东地区凉高山组沉积演化受秦岭造山带构造活动的控制,沉积早期湖盆局限在研究区东侧,该时期以Ⅰ类物源为主;随着秦岭造山带南北向挤压作用的增强,湖盆快速扩张并向北迁移,Ⅱ类物源供给增强;沉积中后期北大巴山地区的隆升使得湖盆迁移的同时Ⅲ类物源的供给逐渐增强。Based on the data of outcrops,seismic sections,thin sections,heavy mineral assemblages and detrital zircon U-Pb dating,the sedimentary characteristics,lake level fluctuation and provenance characteristics of the Middle Jurassic Lianggaoshan Formation(J2l)in eastern Sichuan Basin,SW China,were investigated to reveal the control of tectonic movements of the surrounding orogenic belts on the sedimentary systems.The J2l mainly developed a delta–lake sedimentary system,which contained a complete third-order sequence that was subdivided into four lake level up-down cycles(fourth-order sequence).The lake basins of cyclesⅠandⅡwere mainly distributed in eastern Sichuan Basin,while the lake basins of cyclesⅢandⅣmigrated to central Sichuan Basin,resulting in the significant difference in sedimentary characteristics between the north and the south of eastern Sichuan Basin.The provenance analysis shows that there were three types of provenances for J2l.Specifically,the parent rocks of TypeⅠwere mainly acidic igneous rocks and from the proximal northern margin of the Yangtze Plate;the parent rocks of TypeⅡwere intermediate-acid igneous rocks and metamorphic rocks and from the central parts of the southern and northern Qinling orogenic belts;the parent rocks of TypeⅢwere mainly metamorphic rocks followed by intermediate–acid igneous rocks,and from the North Daba Mountain area.It is recognized from the changes of sedimentary system and provenance characteristics that the sedimentary evolution of J2l in eastern Sichuan Basin was controlled by the tectonic compression of the Qinling orogenic belt.In the early stage,the lake basin was restricted to the east of the study area,and TypeⅠprovenacne was dominant.With the intensifying north-south compression of the Qinling orogenic belt,the lake basin expanded rapidly and migrated northward,and the supply of TypeⅡprovenance increased.In the middle and late stages,the uplift of the North Daba Mountain led to the lake basin migration and the gradual increase in the su

关 键 词：四川盆地 侏罗系 凉高山组 重矿物组合 锆石U-Pb定年 湖盆迁移 物源分析 盆山演化 

分 类 号：TE121.3[石油与天然气工程—油气勘探]