四川盆地及周缘地区寒武系洗象池群岩相古地理研究

发布时间：2018-01-14 11:34

本文关键词：四川盆地及周缘地区寒武系洗象池群岩相古地理研究　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文定位于四川盆地及周缘地区寒武系洗象池群岩相古地理研究。综合前人资料和相关研究成果,以123份野外剖面和41份钻孔资料为主要依据,运用岩石地层学、生物地层学、碳酸盐岩岩石学和碳酸盐沉积学等相关理论,采用单因素分析多因素综合作图法编绘了洗象池群岩相古地理图,揭示沉积期岩相古地理演化和分布特征,为后期研究区的油气勘探提供参考。主要成果和认识有： 1、通过对区域地质背景和洗象池群残余地层厚度展布特征分析认为,研究区洗象池群地层总体具西北薄东南厚、地形上隆坳相间的展布特征。西接康滇古陆,北邻摩天岭古陆和汉南古陆,南部和东北部分别被仁怀-遵义-湄潭等地的黔中水下古隆起和镇巴-城口-巫溪-神农架等地呈带状的水下高地所环绕；而盆内则具有川中乐山-龙女寺古隆起、巴中-通江等地和盆地东南缘赤水-基江-石柱两个次坳；研究区的东北部和东南部分别与秦岭洋和江南盆地相接。 2、研究区岩石类型以碳酸盐岩为主,其次是碎屑岩和变质岩。碳酸盐岩以白云岩为主,根据其成分、结构和构造等特征可进一步细分为颗粒白云岩、细-中晶白云岩和泥-粉晶白云岩；石灰岩在研究区东部比较发育,包括颗粒石灰岩、灰泥石灰岩及其过渡类型；碎屑岩主要分布在研究区西北部,包括砂岩、粉砂岩和粘土岩等；而变质岩以板岩、千枚岩和片岩为主。 3、从岩石类型、沉积构造、沉积旋回以及测井响应特征等角度对区内野外剖面和钻孔资料的研究和分析,同时综合前人的研究资料、成果以及相关地质资料,认为研究区洗象池群发育古陆、碳酸盐岩台地、台地边缘带、斜坡和盆地等沉积环境,其中区内碳酸盐台地发育甚是广泛,可进一步划分出混积潮坪、台坪、局限泻湖、半局限泻湖、蒸发-半局限泻湖和台内滩六种次级环境单元。 4、结合上述分析,采用“单因素分析多因素综合作图”法,对研究区寒武系洗象池群岩相古地理进行了研究,并建立了沉积相模式。认为洗象池期四川盆地西北边存在古陆；盆内主要以局限泻湖沉积为主,环境低能、水体受限,沉积物以灰色-深灰色泥云岩和泥晶云岩为主；盆地西南边的峨边、乐山等地发育陆源碎屑与碳酸盐岩不同程度混积的混积潮坪亚相；盆地以南的金沙-湄潭一带则发育具蒸发环境的蒸发-局限泻湖亚相；而位于盆地外缘西南部镇雄-珙县和东部沿河-咸丰-五峰一带,以石灰岩和白云岩几乎对等沉积,水体相对开阔,发育半局限泻湖亚相；颗粒滩主要分布在位于川中的乐山-龙女寺古隆起区、研究区南部金沙-湄潭-遵义的黔中古隆起区、东北缘城口-神农架和东南缘江口-永顺-桑植一带的水下高地；向研究区东北和东南方向过渡为半深水斜坡和深水盆地相。
[Abstract]:This study focuses on the lithofacies paleogeography of Sichuan basin and its surrounding areas. The Cambrian XIXIANGCHI group of previous information and related research results, with 123 copies of 41 copies of field profile and drilling data as the main basis, using rock stratigraphy, biostratigraphy, carbonate petrology and carbonate sedimentology and other related theories, using the single factor analysis and comprehensive mapping the factor method making XIXIANGCHI group lithofacies palaeogeography map, reveal the depositional paleogeographic evolution and distribution characteristics, and provide reference for later research area of oil and gas exploration. The main achievements and knowledge are:
1, based on the regional geological background and XIXIANGCHI group of residual stratum thickness distribution analysis, the study area XIXIANGCHI group formation has overall northwest southeast thin thickness, distribution of uplift and depression terrain. The west of Kangdian old land, north of Motianling old land and Hannan old land south and northeast, respectively by Renhuai - Zunyi - Meitan, Guizhou in the ancient uplift and Zhenba Chengkou - Wuxi - Shennongjia, is surrounded by bands of underwater heights; and the basin is Sichuan in Leshan longnusi paleo uplift, Bazhong - Tongjiang and southeastern margin of Chishui basin based Jiang Shizhu two times depression; the study area of the northeast and southeast are respectively connected with Qinling Mountains Ocean and the south of the Yangtze River Basin.
2 rock types in the study area, carbonate rocks, clastic rocks and metamorphic rocks. The carbonate rock is dolomite, according to its composition, structure and structure characteristics can be further divided into grain dolomite, fine MICROTEK dolostone and micritic dolomite; development of limestone in the study area in the East, including the particles of limestone, limestone plaster and transitional type; clastic rocks are mainly distributed in the northwest of the study area, including sandstone, siltstone and clay rocks and metamorphic rocks; in slate, phyllite and schist.
3, from the tectonic and sedimentary rock types, sedimentary cycles and logging response characteristics of research and analysis of the field profile and drilling data, and research data based on previous results, and the related geological data, it is concluded that the development of palaeocontinental XIXIANGCHI group, carbonate platform, platform margin slope, sedimentary environment and the basin area, the carbonate platform development is very broad, can be further divided into mixed tidal flat, platform, restricted lagoon, semi restricted lagoon, the evaporation of semi restricted lagoon and intraplatform six secondary environmental units.
4, the combination of the above analysis, the single factor analysis and comprehensive mapping "method of multi factors of lithofacies palaeogeography of the Cambrian XIXIANGCHI group was studied, and the sedimentary facies model is built. That XIXIANGCHI period northwest of Sichuan basin are mainly confined to the basin land; lagoon sediments, water environment and low energy, limited, sediment the grey and dark grey argillaceous dolomite and micrite dolomite; the southwest edge of the Ebian basin, Leshan, the development of terrigenous clastic and carbonate rocks of different degree of hunji mixed tidal flat subfacies; basin to the south of Jinsha - Meitan area development environment with evaporation evaporation and restricted lagoon subfacies; and is located in the southwest the outer part of the basin of Eastern Gongxian and Zhenxiong River - Xianfeng - five peak area, with limestone and dolomite almost equal deposition, the water is relatively open, the development of semi restricted lagoon subfacies; particles are mainly distributed in the beach is located in Sichuan in Leshan longnvsi paleo uplift area, south of the research area, Jinsha - Meitan - Zunyi Middle Guizhou Uplift Area, northeastern and southeastern margin of Chengkou Shennongjia estuary - Yongshun - Sangzhi area under water upland; semi deep slope and deep-water basin phase transition to the study area in Northeast and Southeast.

【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P531;P618.13

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