岩性油气藏 ›› 2025, Vol. 37 ›› Issue (4): 159–168.doi: 10.12108/yxyqc.20250415

• 地质勘探 • 上一篇    

辽中凹陷南部渐新世东营期古地貌特征及其对沉积体系的控制作用

刘秀美1,2, 辛仁臣1,2, 刘豪1,2   

  1. 1. 中国地质大学(北京)海洋学院, 北京 100083;
    2. 中国地质大学(北京)极地地质与海洋矿产教育部重点实验室, 北京 100083
  • 收稿日期:2024-08-01 修回日期:2025-02-21 发布日期:2025-07-05
  • 第一作者:刘秀美(2002-),女,中国地质大学(北京)在读硕士研究生,研究方向为沉积地质。地址:(100083)北京市海淀区学院路29号。Email:2810973325@qq.com。
  • 通信作者: 刘豪(1974-),男,博士,教授,主要从事沉积学、层序地层学和油气地质学方面的研究。Email:lhcugb@163.com。
  • 基金资助:
    十三五国家科技重大专项子课题“辽中凹陷中南洼层序格架、沉积体系与岩性地层圈闭预测”(编号:2016ZX05024-003-003)资助。

Paleogeomorphological characteristics of Oligocene Dongying period in southern Liaozhong Sag and its control on sedimentary system

LIU Xiumei1,2, XIN Renchen1,2, LIU Hao1,2   

  1. 1. School of Ocean Sciences, China University of Geosciences(Beijing), Beijing 100083, China;
    2. Key Laboratory of Polar Geology and Marine Mineral Resources(China University of Geosciences, Beijing) Ministry of Education, Beijing 100083, China
  • Received:2024-08-01 Revised:2025-02-21 Published:2025-07-05

摘要: 古地貌是盆地沉积充填过程与动力学背景研究的基础。在岩心、测井、录井以及三维地震资料综合分析基础上,运用构造沉积学、地震沉积学的理论和方法,对辽中凹陷南部渐新统东营组进行了古地貌重建和沉积相分析,并阐明了古地貌对沉积的控制作用。研究结果表明:①辽中凹陷南部东营组发育隆起带、斜坡带、浅洼带和深洼带4种构造地貌单元,地貌之间发育断裂坡折带,整体呈现“东西分带,南北分块”的特征。②研究区东营组主要发育辫状河三角洲、曲流河三角洲、网状河三角洲、湖底扇以及湖泊相等多种类型,沉积相类型及其展布明显受古地貌的控制:东三段湖侵域(ESTd3)—东二段湖侵域(ESTd2)沉积时期,裂陷作用强烈,湖侵域沉积时期辽西低凸起和南部隆升凸起为主要物源区,洼陷区接受近源沉积,控制了辫状河三角洲的发育;东三段高位域(HSTd3)沉积时期,随着湖平面上升,隆起区转变为水下低隆起,发育滨浅湖滩坝沉积;东二段高位域(HSTd2)—东一段(SQd1)沉积时期,断裂活动减弱,先存古隆起转变为水下低隆,近北东—南西向2个条形洼陷带为远源曲流河三角洲的发育提供了重要的地貌背景。

关键词: 古地貌, 断裂坡折带, 沉积体系, 河流三角洲, 湖底扇, 东营期, 渐新世, 辽中凹陷

Abstract: Paleogeomorphology is the foundation of the study of sedimentary filling process and dynamic background in basins. Based on the data of core, well logging, master logging and 3D seismic, the structural sedimentology and seismic sedimentology were applied to reconstruct the paleogeomorphology and analyze the sedimentary facies of Oligocene Dongying Formation in southern Liaozhong Sag,and the control of paleogeomorphology on sedimentation was clarified. The results show that: (1)Dongying Formation in southern Liaozhong Sag develop four types of structural geomorphic units: uplift zone,slope zone,shallow subsag zone and deep subsag zone. The geomorphic units are controlled by fault slope-break zones,showing an overall feature of“east-west zoning and north-south blocking”.(2)Dongying Formation in the study area mainly develops braided river delta,meandering river delta,anastomosing river delta,sublacustrine fan and lake.The types and distribution of sedimentary facies are obviously controlled by paleogeomorphology: During the sedimentary period of ESTd3-ESTd2,the rifting process was strong. During the lacustrine expansion period,the Liaoxi low uplift and the south bulge rise were the main provenance areas,and the subsag area received near-source deposits,which controlled the development of braided river delta. During the sedimentary period of HSTd3,along with the elevation of lake level,the uplift area transformed into underwater low uplift,and shore-shallow lake beach-bar sand deposits were developed. During the sedimentary period of HSTd2-SQd1,the fault activity weakened,and the pre-existing paleo-uplift transformed into underwater low uplift. The two strip-shaped subsag zones in northeast-southwest direction provided important geomorphic background for the development of the distal meandering river delta.

Key words: paleogeomorphology, fault slope-break zone, sedimentary system, river delta, sublacustrine fan, Dongying period, Oligocene, Liaozhong Sag

中图分类号: 

  • TE121
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