准噶尔盆地及邻区石炭纪构造格架与沉积充填演化

发布时间：2018-01-10 17:35

本文关键词：准噶尔盆地及邻区石炭纪构造格架与沉积充填演化　出处：《中国地质大学(北京)》2016年博士论文　论文类型：学位论文

【摘要】：准噶尔盆地及邻区隶属古亚洲洋构造域,记录了中亚增生造山带的俯冲、增生、碰撞以及后期陆内改造过程。石炭纪是古亚洲洋由俯冲到闭合的关键转折期,该时期复杂的洋-陆演变过程造就了准噶尔盆地石炭系的油气成藏实例。然而,石炭纪原型盆地研究目前仍比较薄弱,抑制了对石炭系生储条件和有利区带的评价。因此,开展准噶尔地区石炭纪构造格架和充填演化的研究,不仅可以丰富对中亚增生造山带的构造演化的认识,同时也对推进深层含火山岩盆地油气勘探进程具有重要的意义。本论文系统应用构造地质学、地球物理学、同位素年代学和地球化学方法,综合利用钻井、野外露头、地震和重磁等资料,对准噶尔盆地及邻区石炭系年代地层格架、地质结构、大地构造环境、沉积充填序列进行了系统的分析和研究。在此基础上,揭示了准噶尔盆地及邻区石炭纪构造格架以及多期构造背景下的构造-沉积环境演变特征。盆地钻井火山岩年代学结果显示准噶尔地区石炭纪发育5期火山活动,包括早石炭世3期(359-347Ma,347-331Ma和331-324Ma),晚石炭世2期(323-307Ma和307-300Ma)。区域性不整合界面将石炭系划分为上、下石炭统两个构造地层层序。下石炭统以挤压构造变形为主,发育大量的钙碱性玄武岩、安山岩、英安岩和流纹岩。而上石炭统多受伸展断裂控制,火山岩以中-基性火山岩为主,局部地区存在双峰式火山岩组合。基于火山岩构造环境分析结果及构造变形研究,并结合准噶尔盆地及邻区石炭纪构造带的划分方案,厘定了萨乌尔-福海-杜拉特、和什托洛盖-乌伦古-野马泉、达尔布特-陆梁-卡拉麦里、中拐-莫索湾-白家海-奇台等4个石炭纪弧盆带,并识别了弧前盆地、弧后盆地、弧内断陷盆地、前陆盆地、被动边缘盆地等多种类型盆地。在构造格架建立的基础上,通过对石炭纪盆地沉积充填序列的解剖,将准噶尔盆地及邻区石炭纪构造-沉积环境演变过程划分为3个阶段,分别为早石炭世早-中期俯冲作用相关挤压挠曲阶段、早石炭世晚期-晚石炭世中期俯冲相关的伸展裂陷阶段和晚石炭世晚期陆内断坳陷阶段。研究结果不仅揭示准噶尔盆地下伏年轻陆壳基底,而且表明准噶尔盆地及邻区乃至整个中亚增生造山带是在多列南向增生的弧盆系统依次向北碰撞拼贴过程中形成的。
[Abstract]:The Junggar basin and its adjacent area belong to the Paleo-Asian oceanic tectonic domain, recording the subduction, accretion, collision and later intra-continental transformation of the Central Asian accretionary orogenic belt. Carboniferous is the key turning period of the paleo-Asian ocean from subduction to closure. The complicated ocean-land evolution in this period resulted in the hydrocarbon accumulation in Carboniferous in Junggar Basin. However, the study of Carboniferous prototype basin is still relatively weak. Therefore, the study of Carboniferous tectonic framework and filling evolution in Junggar area can not only enrich the understanding of the tectonic evolution of the Central Asia accretionary orogenic belt. At the same time, it is of great significance to promote the process of oil and gas exploration in deep volcanic basins. In this paper, structural geology, geophysics, isotopic chronology and geochemistry are systematically applied to the comprehensive use of drilling. Based on the data of outcrop, earthquake and gravity and magnetic field, the chronostratigraphic framework, geological structure, tectonic environment and sedimentary filling sequence of Carboniferous in Junggar Basin and adjacent area are systematically analyzed and studied. The evolution characteristics of tectonic-sedimentary environment in Carboniferous tectonic framework and multi-stage tectonic setting in Junggar Basin and adjacent area are revealed. The geochronological results of volcanic rocks in the basin indicate that the 5th stage volcanic activity developed in the Carboniferous period in Junggar area. . It includes early Carboniferous period 3 (359-347 Ma, 347-331Ma and 331-324 Ma). The late Carboniferous stage 2: 323-307 Ma and 307-300 Ma. The regional unconformity interface divides the Carboniferous into upper. The Lower Carboniferous is dominated by compressional structural deformation, and a large number of calc-alkaline basalt, andesite, andesite and rhyolite are developed, while the Upper Carboniferous is controlled by extensional faults. The volcanic rocks are mainly meso-basic volcanic rocks, and there are bimodal volcanic assemblages in local areas. Based on the results of structural environment analysis and structural deformation study of volcanic rocks. Combined with the division scheme of Carboniferous structural belts in Junggar Basin and adjacent areas, the authors have determined the Sawur-Fuhai-Durat, the Shitoroge-Ulungue-Mumaquan, and the Dalbut-Luliang-Kalamaili. There are four Carboniferous arc basin belts in Zhongguai Mosuowan-Baijiahai Qitai, and the forearc basin, back-arc basin, intraarc faulted basin and Foreland basin are identified. Based on the establishment of tectonic framework, the sedimentary filling sequence of Carboniferous basin is dissected. The evolution process of the Carboniferous tectonic-sedimentary environment in Junggar Basin and its adjacent area is divided into three stages, which are the early to mid-Carboniferous compression-related deflections. The extensional rift stage associated with subduction in late early Carboniferous to mid-late Carboniferous and intracontinental fault depression stage in late late late Carboniferous. The results not only reveal the underlying young continental crust in Junggar Basin. It also shows that the Junggar basin and its adjacent area and even the whole Central Asia accretive orogenic belt were formed in the process of collision and collage of the arc-basin system in the direction of multi-row southward accretion.
【学位授予单位】：中国地质大学(北京)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P618.13

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