四川盆地西北缘天井山古隆起的形成与演化  

Formation and evolution of Tianjingshan paleo-uplift, northwestern margin of Sichuan Basin

作　　者：李国辉[1] 杨光[1] 李莉[1] 李楠[1] 戴鑫[1] 陈双玲[1] 周红飞[1] 苑保国[1] Li Guohui;Yang Guang;Li Li;Li Nan;Dai Xin;Cheng Shuangling;Zhou Hongfei;Yuan Baoguo(Exploration and Development Research Institute,PetroChina Southwest Oil & Gasfield Company,Chengdu,Sichuan 610051,China)

机构地区：[1]中国石油西南油气田分公司勘探开发研究院

出　　处：《天然气勘探与开发》2018年第4期1-7,共7页Natural Gas Exploration and Development

基　　金：中国石油天然气股份有限公司重大科技专项"四川盆地天然气资源潜力分析及新区新领域勘探目标评价"(编号:2016E-0601);"四川盆地震旦系-下古生界油气富集规律与目标评价"(编号:2016E-0602)

摘　　要：四川盆地乐山—龙女寺古隆起和天井山古隆起均形成于早古生代,对前者的研究相对较多,而对天井山古隆起的关注还不够。近年,在龙门山冲断带北段发现了双鱼石二叠系及泥盆系气藏,为此开展了天井山古隆起的形成与演化研究。基于地面地质、钻井、地层及沉积、构造演化等资料的综合分析表明:(1)早寒武世早期,天井山古隆起即具水下隆起特征,在早寒武世晚期隆升成陆,形成于志留纪末;(2)泥盆纪—中三叠世,天井山古隆起相对平静,晚三叠世始,由于龙门山推覆作用使古隆起再度活跃,遭受抬升剥蚀,侏罗系超覆在寒武系—三叠系不同层位上;(3)古隆起的形成动力源于扬子板块东南缘与华夏地块挤压的应力传导和板块西、北边缘刚性杂岩体阻挡共同作用,而古隆起再度活跃的动力则源于松潘—甘孜洋关闭及龙门山构造带的推覆抬升作用;(4)在晚三叠世前,现今的川西拗陷为联合古隆起下斜坡,有利于烃类聚集,而现今龙门山构造带则位于联合古隆起顶部或上斜坡。结论认为:龙门山构造带推覆体下部具有油气勘探潜力。Both Leshan-Longnvsi and Tianjingshan paleo-uplifts,Sichuan Basin,formed in the early Paleozoic.But,the study on the former is much more than that of the latter.Recently,along with some Permian and Devonian Shuangyushi gas reservoirs discovered in the northern Longmenshan thrust belt,several researches on the formation and evolution of Tianjingshan paleo-uplift have been carried on.In this study,based on some analysis on surface,geology,drilling,stratigraphy,depositional,and structural evolution data,it’s illustrated that(1)Tianjingshan paleo-uplift presents some characteristics of underwater uplift in the early stage of early Cambrian,then uplifted to be a land in the late stage of early Cambrian,and formed at the end of Silurian;(2)this uplift was relatively stable from Devonian to Middle Triassic.Then,under napping effect of Longmenshan Mountain,it got reactivated and suffered uplifting and denudation,resulting in many Cambrian-Triassic strata overlapped by Jurassic ones;(3)driving force to generate Tianjingshan paleo-uplift was originated from one stress transmission caused by extrusion of both southeastern margin of Yangtze plate and Huaxia massif and another blocking action of rigid complexes in the western and northern margins of the plate.And other driving force for its reactivation was came from the closure of Songpan-Ganzi Ocean and the napping and uplifting of Longmenshan structure belt;and(4)before late Triassic,the current West Sichuan Depression was the lower slope of complex paleo-uplift where it was favorable for hydrocarbon accumulation,and the current Longmenshan structure belt was located at the top or upper slope of complex paleo-uplift.In conclusion,it is deemed that there is a certain exploration potential in the lower part of Longmenshan nappe.

关 键 词：四川盆地 天井山古隆起 龙门山构造带 形成与演化 控藏作用 勘探潜力 

分 类 号：P618.13[天文地球—矿床学]