准噶尔盆地东南缘中—新生代盆山关系及构造演化过程

发布时间：2018-01-15 14:36

本文关键词：准噶尔盆地东南缘中—新生代盆山关系及构造演化过程　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：准噶尔盆地东南缘由依连哈比尔尕山、柴窝堡凹陷,博格达山和博格达山北缘构造带所构成,呈现出盆地和山脉镶嵌的格局,构成了独具特色的复杂地质结构和构造演化过程。对其中-新生代变形特征及构造演化的研究,将对揭示天山北缘中-新生代陆内变形机制和提高该区油气勘探的认识具有重要意义。本文通过对准噶尔盆地东南缘的构造变形特征以及沉积充填特征进行研究,结合造山带隆升史,分析准噶尔盆地东南缘地区的构造演化特征,探讨其整体演化过程,并初步取得了如下主要认识:1.博格达山南缘柴窝堡凹陷内识别出三期不整合,分别是侏罗系与三叠系(J/T),古近系与侏罗系(E/J),上新统与中新统之间的不整合(N2/N1),厘定柴窝堡凹陷中-新生代至少经历了晚三叠世末期,侏罗纪-古近纪之间,中新世末期三期构造变形;而博格达山北缘构造带识别出侏罗系与三叠系(J/T),白垩系与侏罗系(K/J),古近系与白垩系(E/K)以及上新统与中新统(N2/N1)四期不整合,厘定出晚三叠世末期、晚侏罗世末期、晚白垩世末期和中新世末期这四期构造变形事件。2.准噶尔东南缘地区基本变形结构主要受深层滑脱断层向北扩展所控制:依连哈比尔尕山向北挤压的过程中,在其北侧山前发育基底卷入断层;挤压应力由南往北沿深部滑脱断层传播到博格达山,在其南侧形成向南的反冲断层及其断层相关褶皱;逆冲作用继续沿滑脱断层向北传播,在博格达山北侧形成向北的逆冲断层及其断层相关褶皱。柴窝堡凹陷的总体结构表现为南北对冲的构造三角带;而博格达山整体呈扇形表现为类似冲起构造。3.中-晚侏罗世构造与沉积响应模式可用楔顶沉积进行解释:中-晚侏罗世博恪达山北缘逆断层强烈冲断,导致柴窝堡凹陷和博格达山整体抬升,处于楔顶位置,沉积厚度薄的河流相沉积,此时博格达山北缘构造带位置处于前渊坳陷,沉积了厚度较大的湖相沉积体系,造成侏罗系在博格达山南北缘的巨大沉积差异;上新世以来的构造变形表现为依连哈比尔尕山北缘和博格达山北缘强烈冲断,导致山前地层发生挠曲下沉,上新统及第四系沉积南厚北薄,整体呈前陆盆地特征。柴窝堡凹陷可能为冲断带内背驮盆地,博格达山北缘构造带北部地区属于前渊坳陷。4.提出准噶尔盆地东南缘中-新生代演化过程:三叠系在准噶尔东南缘接受整体拗陷沉降,晚三叠世末博格达山隆起成为低隆;早-中侏罗世研究区为伸展坳陷,中-晚侏罗世发育楔顶沉积,造成博格达山南北缘侏罗系巨大沉积差异,侏罗末博格达山强烈隆升;白垩纪柴窝堡处于较高位置,不接受沉积,而博格达山北缘沉积白垩系;进入古近系研究区发育拗陷沉积,中新世末依连哈比尔尕山及博格达山北缘山前地层强烈挠曲下沉,上新统以来地层沉积南厚北薄,柴窝堡凹陷为背驮盆地,北缘构造带北部地区属于前渊坳陷。
[Abstract]:The southeast of Junggar basin is composed of the structural belts of the northern margin of Ylianhabigashan, Chaiwopu sag, Bogda mountain and bogda mountain, showing the pattern of basin and mountain mosaic. It constitutes a unique complex geological structure and tectonic evolution process. The study of deformation characteristics and tectonic evolution of the Mesozoic and Cenozoic. It will be of great significance to reveal the deformation mechanism of Mesozoic and Cenozoic in the northern margin of Tianshan Mountain and to improve the understanding of oil and gas exploration in this area. This paper studies the structural deformation characteristics and sedimentary filling characteristics of the southeastern margin of Junggar Basin. . Based on the uplift history of the orogenic belt, the structural evolution characteristics of the southeastern margin of Junggar Basin are analyzed, and the overall evolution process is discussed. The main results are as follows: 1. Three unconformities have been identified in Chaiwopu sag in the southern margin of Bogda Mountain, namely, Jurassic and Triassic J / T, Paleogene and Jurassic E / J). The unconformity between Pliocene and Miocene (N _ 2 / N _ 1) indicates that the Mesozoic to Cenozoic in Chaihuopu sag experienced at least the late Triassic, Jurassic-Paleogene, and late Miocene tectonic deformations. On the other hand, the northern margin of Bogda Mountain identified Jurassic and Triassic J / T, Cretaceous and Jurassic K / J). The four unconformity periods of Paleogene and Cretaceous (E / K) and Pliocene and Miocene (N _ 2 / N _ 1) determined the late late Triassic and the late Jurassic. The four tectonic deformation events of the late late Cretaceous and the late Miocene. 2. The basic deformation structure in the southeast margin of Junggar is mainly controlled by the northward extension of the deep detachment fault. In the course of the northward extrusion of Ilenhabilga Mountain. The basement involvement fault is developed in the north side of the mountain front; The compressive stress propagates from south to north along the deep slip fault to Bogda Mountain and forms southward recoil fault and its related fold in the south side. The thrust continued to propagate northward along the slip fault and formed a northward thrust fault and its related folds on the north side of the Bogda Mountains. The whole Bogda Mountain is fan-shaped. 3. Middle-Late Jurassic tectonics and sedimentary response model can be explained by wedge top deposition: the thrust fault in the northern margin of Middle-Late Jurassic Shikeda Mountain. As a result, Chaiwopu sag and Bogda Mountain are uplifted at the top of the wedge and deposited in fluvial facies with thin thickness. At this time, the northern margin of Bogda Mountain tectonic belt is located in the Qianyuan Depression. The thicker lacustrine sedimentary system resulted in the huge difference of Jurassic in the north and south margin of Bogda Mountain. The tectonic deformation since the Pliocene is characterized by a strong thrust on the northern margin of the Ilenhabierga Mountains and the northern margin of the Bogda Mountains, resulting in the flexural subsidence of the strata in front of the mountains, and the thickness of the Pliocene and Quaternary deposits in the south and north. The whole is a Foreland basin. Chaiwopu depression may be a piggyback basin in the thrust belt. The northern part of the northern Bogdashan tectonic belt belongs to the Qianyuan Depression. 4. The Meso-Cenozoic evolution process of the southeastern margin of Junggar Basin is put forward: the Triassic system accepts the whole depression subsidence in the southeast margin of Junggar Basin. At the end of the late Triassic, the Bogda mountain uplift became low uplift; The early and middle Jurassic study area is an extensional depression, and the middle to late Jurassic developed wedge top deposition, which resulted in the huge difference of Jurassic deposits in the north and south margin of the Bogda Mountains, and the strong uplift of the Bogda Mountains in the late Jurassic. The Cretaceous Chaiwopoubao was in a higher position and did not accept the deposits, while the Cretaceous was deposited in the northern margin of the Bogda Mountains. In the Paleogene study area, the depressions were developed, the Piedmont strata in the northern margin of Ylianhabigashan and Bogda Mountains in late Miocene were strongly flexural and subsided, the deposits since the Pliocene were thin in the south and north, and the Chaiwopu depression was a piggyback basin. The northern part of the northern margin of the tectonic belt belongs to the Qianyuan Depression.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P542

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