重新划分塔里木盆地塔北隆起的次级构造单元  

Redivision of the tectonic units of Tabei Rise in Tarim Basin,NW China

作　　者：李曰俊[1] 杨海军[2] 张光亚[3] 郑多明[2] 刘云祥[2] 赵岩[1] 李国会[2] 刘亚雷[1] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]中国石油塔里木油田公司,库尔勒841000 [3]中国石油勘探开发研究院,北京100083

出　　处：《岩石学报》2012年第8期2466-2478,共13页Acta Petrologica Sinica

基　　金：国家科技重大专项课题(2011ZX05028-003);国家"973"课题(2006CB202301);塔里木油田联合资助

摘　　要：塔北隆起位于塔里木盆地北部,是塔里木盆地油气最富集的构造单元之一。其在古生代克拉通内古隆起的基础上,于二叠纪末-三叠纪早期定型为库车周缘前陆盆地的前缘隆起。新生代,其整体沉降,成为埋藏于北塔里木陆内前陆盆地前渊下的一个残余古隆起。目前通用的塔北隆起构造单元划分方案不能准确反映其真实的构造格局。根据最新的研究成果,我们建议重新划分塔北隆起构造单元:(1)取消哈拉哈塘凹陷和草湖凹陷,重新定义轮南低凸起。重新定义的轮南低凸起包括原轮南低凸起、哈拉哈塘凹陷和草湖凹陷北部,是一个下古生界大型鼻状背斜构造,形成于前石炭纪;原草湖凹陷南部划归北部坳陷。(2)以中奥陶统顶面海拔约-6500m的等高线作为塔北隆起的南部边界,该等高线较好地反映了塔北隆起南部的构造轮廓,特别是轮南大型鼻状背斜构造的轮廓。(3)以羊塔1-英买8断裂和英买4-英买1背斜组成的一条较清晰的古生界构造线划分轮台凸起和英买力低凸起。此界线两侧,古生界各反射层存在陡然、明显的落差,岩浆作用、地层发育、构造变形和演化历史存在明显差异。重新划分的塔北隆起包括库尔勒鼻状凸起、轮台凸起、轮南低凸起、英买力低凸起和温宿鼻状凸起五个次级构造单元。本文给出了塔北隆起及其各次级构造单元清晰的定义和范围,并简单论述了其形成演化过程。In the northern part of Tarim basin, the Tabei Rise is one of the tectonic units richest in oil and gas accumulation. Based on the Paleozoic intra-craton uplift, it developed into the forebulge of Kuqa peripheral foreland basin in terminal Permian-Early Triassic. During Cenozoic it subsided entirely and became a residue of paleo-uplift buried beneath the foredeep of the intracontinental foreland basin in northern Tarim. The existing division of the tectonic units of Tabei Rise cannot accurately reflect its real tectonic framework. New evidence indicates that the redivision of the tectonic units of Tabei Rise is likely： （ 1 ） to cancel the Halahatang Sag and Caohu Sag and redefine the Lunnan Lower Uplift, which includes the former Lunnan Lower Uplift, Halahatang Sag and the Northern part of Caohu Sag. The redefined Lunnan Lower Uplift is a large anticlinal nose developed in pre-Carboniferous. The southern part of the former Caohu Sag reallocates to the Northern Depression. （2） The -6500m altitude contour of the Middle Ordovisian top surface is considered to be the southern boundary of Tabei Rise. The contour fairly well reflects the tectonic configuration of the Tabei Rise, particularly the configuration of the large anticlinal nose. （ 3 ） The Luntai Uplift and Yingrnaili Lower Uplift are delineated clearly by a Paleozoic structure line composed by the Yangtal-Yingmai 8 fault and the Yingmai 4-Yingrnai 1 anticline. On the two sides of this line, each Paleozoie reflecting layer exhibits remarkable abrupt throw, and the magmatism, stratigraphy, structural deformation and evolution history are also contrasted obviously. The redivision of Tabei Rise includes five secondary tectonic units, i.e. the Korla noseshaped uplift, Luntai Uplift, Lunnan Lower Uplift, Yingmaili Lower Uplift and Akesu Nose-shaped Uplift. This paper will provide the definition and scope of the Tabei Rise and its secondary tectonic units as well as brief description of their evolution.

关 键 词：构造单元划分 塔北隆起 轮南低凸起 哈拉哈塘凹陷 草湖凹陷 英买力低凸起 前石炭纪克拉通内隆起 二叠纪末-三叠纪前缘隆起 晚新生代深埋古隆起 

分 类 号：P544[天文地球—构造地质学]