准噶尔盆地东部阜北地区中侏罗统头屯河组物源分析

发布时间：2018-03-31 15:34

本文选题：物源分析　切入点：头屯河组　出处：《成都理工大学》2017年硕士论文

【摘要】：准噶尔盆地东部阜康东环带北部地区(以下简称阜北地区)侏罗系主要属湖泊-三角洲沉积体系,中侏罗统屯河组近年来已成为新疆油田重要的勘探层系之一,受到了人们的普遍关注。虽然诸多学者对准噶尔盆地侏罗系物源及沉积相获得了较多认识,但这些认识大多基于整个准噶尔盆地,且层位主要集中在三工河组和八道湾组,对于剥蚀比较严重的头屯河组的物源分析则较少,针对阜康东环带侏罗系头屯河组物源的研究则更少。本文在前人已有成果基础上,结合钻井岩心观察,并运用砂岩碎屑组分定量统计、重矿物组合及其指数分析、阴极发光分析、合微量元素和稀土元素沉积地球化学分析,以及针对阜北地区头屯河组沉积特征综合研究,试图弄清头屯河组主物源方向、母岩性质以及物源区构造背景,为深化该地区地质认识及指导下步油气勘探提供支撑。依据野外露头、钻井岩心、测井和地震资料综合分析,认为准噶尔盆地东部阜北地区头屯河组属辫状河三角洲沉积相,并划分出三角洲平原、三角洲前缘和前三角洲亚相和11类沉积微相,沉积充填序列呈现出粗-细-粗-细的变化趋势。沉积相带的平面展布具有从北东向南西由辫状河三角洲向湖泊演变的沉积规律。阜北地区中侏罗统头屯河组砂岩以长石岩屑砂岩为主,其次为岩屑砂岩,碎屑组分中石英主要由单晶石英组成,同时含有部分变质石英岩屑和沉积岩的燧石岩屑;长石以钾长石为主,斜长石较少;岩浆岩岩屑以霏细岩、玄武岩和安山岩等喷出岩岩屑为主,变质岩岩屑以千枚岩为主,少量片岩岩屑,沉积岩岩屑主要以泥岩岩屑和云母等为主。重矿物组合特征、Dickinson碎屑组分投点图、石英的阴极发光以及微量元素和稀土元素沉积地球化学结果显示,头屯河组的物源方向很可能为北东向,最有可能是来自北东向的克拉美丽山源区,母岩主要以中酸性岩浆岩为主;头屯河组源区的构造背景主要为岩浆岛弧,且主要集中在过渡弧区和未切割岛弧区,并含有火山碎屑及火山-深成岩屑砂岩成分;大地构造环境主要属被动大陆(岛弧)边缘和大洋岛弧源区构造背景。
[Abstract]:Jurassic mainly belongs to lacustrine delta sedimentary system in the northern area of eastern Fukang ring belt in eastern Junggar Basin. Tunhe formation of Middle Jurassic has become one of the important exploration strata in Xinjiang Oilfield in recent years.Has received the general attention of the people.Although many scholars have gained more knowledge of Jurassic provenance and sedimentary facies in Junggar Basin, most of these understandings are based on the whole Junggar Basin, and the horizon is mainly concentrated in Sangonghe formation and Badaowan formation.There is less material source analysis for Toutunhe formation with serious denudation, much less for Jurassic Toutunhe formation in the eastern ring belt of Fukang.On the basis of previous achievements, combined with core observation, quantitative statistics of sandstone clastic components, heavy mineral assemblage and its index analysis, cathodoluminescence analysis, trace elements and rare earth element sedimentary geochemistry analysis are used in this paper.Aiming at the comprehensive study of sedimentary characteristics of Toutunhe formation in Fubei area, this paper attempts to clarify the direction of main provenance, the nature of parent rock and the tectonic background of provenance area, which provides support for deepening geological understanding and guiding oil and gas exploration in the next step.Based on the comprehensive analysis of outcrop, drilling core, logging and seismic data, it is considered that the Toutunhe formation in the eastern Fubei area of Junggar Basin belongs to braided river delta sedimentary facies and is divided into delta plain.The sedimentary filling sequence of delta front, prodelta subfacies and 11 types of sedimentary microfacies shows a trend of coarse-fine-coarse-fine variation.The plane distribution of sedimentary facies belt is characterized by the evolution from braided river delta to lake from north east to south west.Feldspar is dominated by potash feldspar, while plagioclase is less, magmatic debris is dominated by feldspar, basalt and andesite, metamorphic lithoclast is dominated by phyllite and a small amount of schist.Sedimentary lithoclasts are mainly mudstone and mica.The heavy mineral assemblage features of Dickinson clastic composition, cathodoluminescence of quartz, trace elements and REE sedimentary geochemistry indicate that the source direction of the Toutunhe formation is likely to be NE.The source rocks are mainly intermediate-acid magmatic rocks, the tectonic setting of the source area of Toutunhe formation is mainly magmatic island arc, and it is mainly concentrated in transitional arc region and uncut island arc area.The tectonic environment is mainly passive continental (island arc) margin and oceanic island arc source tectonic setting.
【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

【相似文献】