辽西南凹陷古近纪东营期层序充填特征分析

发布时间：2018-03-25 10:12

本文选题：辽西南凹陷东　切入点：营组　出处：《成都理工大学》2017年硕士论文

【摘要】：论文将辽西凹陷南部(即辽西南凹陷)作为研究地区,对古近系东营组的层序及砂体分布做出研究。在对钻井进行岩芯观察及物探资料(测井资料及地震资料等)的解释基础之上,以沉积岩石学、层序地层学、沉积充填动力学、古生物学、沉积地球化学、测井地质学、地震地层学以及构造地质学等原理为理论依据,对研究区内的古近系东营组进行了岩石组合、生物组合、沉积结构、剖面序列、沉积机理等特征的分析。本文对相同沉积时期条件下的横向上及相同沉积位置垂向上的沉积特征做出了分析并进行了对比。本文对研究区内古近系东营组中主要的三种沉积体系——湖泊、辫状河三角洲、近岸水下扇,做出了分析。并在对沉积相的分析基础之上,综合对测井资料及地震剖面资料的分析结果,根据层序地层学原理,参照研究区现有研究状况,将研究区东营组划分为三个三级层序——东营组三段层序(SQd_3)、东营组二段层序(SQd_2)、东营组一段层序(SQd_1)。其中东营组三段层序以半深湖相沉积为主。至东营组二段层序,研究区逐渐转为以辫状河三角洲相沉积为主,见有少量滨浅湖相沉积。到东营组三段沉积时期,研究区则几乎少见湖湘沉积,多见多期辫状河三角洲叠置沉积。反映了研究区在东营组沉积过程中,经历了从东营组三段沉积期辽东湾盆地在快速断裂期的背景下,盆地面积增大,多发育湖泊;到快速断裂期晚期构造活动渐缓的转变,盆地沉降作用渐弱,同时西面来自六股河岩浆岩、变质岩混合物源区和大石河岩浆岩物源区的物源充足的情况下,由湖泊向辫状河三角洲沉积的演化过程。研究区主要接受西部的六股河岩浆岩、变质岩混合物源区和大石河岩浆岩物源区的物源,选取物源方向水平方向和垂直方向,建立了高分辨率层序地层格架。在层序地层分析的基础上,运用层序充填动力学思想,详细讨论了在湖平面、A/S比值变化、层序界面旋回、古地貌及断层,5个因素的控制作用下,对研究区层序内部砂体展布的特征进行了讨论。
[Abstract]:In this paper, the southern part of the western Liaoning sag (that is, the southwest Liaoning depression) is regarded as the research area. The sequence and sand body distribution of Dongying formation in Paleogene are studied. On the basis of core observation and interpretation of geophysical data (logging data, seismic data, etc.), sedimentary petrology, sequence stratigraphy and sedimental-filling dynamics are used. Based on the principles of paleontology, sedimentary geochemistry, logging geology, seismic stratigraphy and tectonic geology, the rock assemblages, bioassemblages, sedimentary structures and profile sequences of the Dongying formation of the Paleogene in the study area have been carried out. Analysis of sedimentary mechanism and other characteristics. This paper analyses and compares the vertical sedimentary characteristics of the same sedimentary period and the same sedimentary position. The main features of Dongying formation of Paleogene in the study area are discussed in this paper. Lakes, The braided river delta, the nearshore underwater fan, is analyzed. On the basis of the analysis of sedimentary facies, the results of well logging and seismic profile data are synthetically analyzed. According to the principle of sequence stratigraphy, the present research situation in the study area is referred to. The Dongying formation in the study area is divided into three third-order sequences-the third member of the Dongying formation, the third member of the Dongying formation, SQdS3, the second member of the Dongying formation, the second member of the Dongying formation, the sequence SQD _ 2, and the first member of the Dongying formation, the sequence of which is mainly composed of semi-deep lacustrine facies deposits, and the sequence to the second member of the Dongying formation, the first member of the Dongying formation, is mainly composed of semi-deep lacustrine facies. The study area gradually changed to braided river delta facies, and a small amount of littoral shallow lacustrine facies was found. In the third member of Dongying formation, Huxiang sediments were almost rare in the study area. There are many braided river delta superimposed deposits in the study area, which shows that in the process of Dongying formation, the Liodong Bay basin in the third member of Dongying formation experienced rapid fault period, the area of the basin increased and lakes developed. With the gradual change of tectonic activity in the late period of rapid faulting, the subsidence of the basin becomes weaker, and in the case of abundant sources from Liukuhe magmatic rock, metamorphic rock mixture source area and Dashihe magmatic source area to the west, The evolution process from lake to braided river delta. The study area mainly accepts the provenance of Liukuhe magmatic rock, the source region of metamorphic rock mixture and the source area of Dashihe magmatic rock, and selects the horizontal and vertical direction of the source. The high-resolution sequence stratigraphic framework is established. On the basis of sequence stratigraphic analysis and using the idea of sequence filling dynamics, it is discussed in detail under the control of five factors, such as the change of A / S ratio in the lake plane, the sequence interfacial cycle, paleogeomorphology and faults, and the control of five factors. The distribution characteristics of sand bodies in the study area are discussed.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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