塔里木新元古代盆地演化与下寒武统烃源岩发育的构造背景

发布时间：2018-05-08 09:16

本文选题：塔里木盆地 + 原型盆地　；参考：《地质学报》2017年08期

【摘要】：下寒武统优质烃源岩的分布一直是塔里木盆地油气勘探的难点问题。在区域构造演化背景分析基础上,利用露头和新的钻井、地震资料,通过地层对比、构造解释和古地貌恢复,探讨了塔里木新元古代盆地原型、古构造及下寒武统烃源岩发育的构造背景。研究认为塔里木盆地西缘的柯坪和叶城地区,新元古代经历了陆内断陷到初始被动大陆边缘的盆地演化序列,而在塔东北的库鲁克塔格地区,主要以裂谷及其衰退期的拗陷为特征。地震反射特征进一步显示在塔里木陆内也具有相似的成盆作用,南华纪断陷具有清楚的垒、堑结构,震旦纪以后以拗陷阶段的均衡沉降为主。发生在晚震旦世末的柯坪运动造成全区抬升,奠定了塔里木盆地寒武系沉积前的构造古地貌,总体表现为西高东低,南高北低,控制了下寒武统烃源岩的形成、分布。塔西台地内中-下寒武统出现大面积增厚,可能与晚震旦世以后继承性的沉降作用有关,形成有利于玉尔吐斯组类型的碳酸盐质陆棚相烃源发育的沉积环境。而西山布拉克-西大山组类型的深水陆棚-盆地相的泥质烃源岩不仅在满加尔坳陷内发育,还可能在阿瓦提坳陷内分布。尽管中央隆起带大部分地区不利于优质烃源岩发育,但不能排除局部地区仍可能存在下寒武统泻湖相烃源岩。与盆地北部高碳酸盐岩含量的烃源岩不同,塔里木南缘改造边界附近具有形成高碎屑岩含量的深水泥质烃源岩的构造-沉积环境。
[Abstract]:The distribution of high quality source rocks in Lower Cambrian is always a difficult problem in oil and gas exploration in Tarim Basin. Based on the background analysis of regional tectonic evolution, the prototype of the Tarim Neoproterozoic Basin is discussed by using outcrop and new drilling and seismic data, through stratigraphic correlation, structural interpretation and paleogeomorphology recovery. Paleotectonics and tectonic setting of source rock development in Lower Cambrian. It is considered that in the Keping and Yecheng areas of the western margin of the Tarim Basin, the Neoproterozoic underwent a series of basin evolution from the intracontinental fault to the initial passive continental margin, while in the Kuruktag area in the northeast of Tarim Basin, It is mainly characterized by the depression of the rift valley and its depression. The characteristics of seismic reflection further show that there is a similar basin formation in Tarim continent. The South China fault depression has clear barrier and graben structure. After the Sinian period, the equilibrium subsidence of depression stage is the main factor. The Keping movement, which occurred at the end of the late Sinian, resulted in the uplift of the whole area, which established the tectonic paleogeomorphology before the Cambrian sedimentation in the Tarim Basin. The general performance of the movement was low in the west, high in the east, and low in the north and south, which controlled the formation and distribution of the source rocks of the Lower Cambrian. The large area thickening of the Meso-Lower Cambrian in the Taxi platform may be related to the inherited subsidence after the late Sinian, forming a sedimentary environment conducive to the development of carbonate shelf hydrocarbon sources of the Yultuisi formation type. The shaly source rocks of the deep water shelf-basin facies of the BRAKE-Xidashan formation are not only developed in the Mangar depression but also possibly distributed in the Awati depression. Although most of the central uplift zone is not conducive to the development of high quality source rocks, it can not be ruled out that there may still exist the Lower Cambrian lagoon facies source rocks in some areas. Different from the source rocks with high carbonate content in the northern part of the basin, there is a tectonic-sedimentary environment for deep-water argillaceous source rocks with high clastic rock content near the remoulding boundary in the southern margin of Tarim Basin.
【作者单位】：中国石化石油勘探开发研究院;中国科学院油气资源研究重点实验室;中国石油化工股份有限公司石油勘探开发研究院无锡石油地质研究所;
【基金】：国家重大专项(编号:2011ZX05005-002-04-01)资助的成果
【分类号】：P534.3;P618.13

【相似文献】