【作者】 滑心爽；

【导师】 陈洪德；

【作者基本信息】 成都理工大学 ， 沉积学， 2010， 硕士

【摘要】 四川盆地是一个面积约19×104km2的大型含气叠合盆地是我国天然气资源丰富的地区之一,在前震旦系变质岩和火成岩的基底上,沉积了厚达6000～12000m的海、陆相地层,是目前西部大开发中西气东输的重要接替区块。但是前人对四川盆地早三叠世飞仙关期岩石学特征和沉积环境研究的重点局限在川东北地区,对川西北该套地层的研究尚处于早期阶段,研究程度亦较低。本文以四川盆地西北部(即川西北地区)下三叠统飞仙关组为研究对象,在野外实测剖面、钻井岩芯观察、测井资料的基础上,以沉积学、古生物学、地球物理学和构造地质学等原理为指导,进行了岩石组合、生物组合、沉积组构、实测剖面、沉积机理等特征的详细分析,划分出碳酸盐台地沉积体系和台盆沉积体系,其中碳酸盐台地沉积体系研究区内主要可以识别出局限台地、开阔台地、台地边缘三种沉积相类型,主要分布在安县以东,剑阁以南,仪陇以西。其中,台地边缘为研究区主要沉积环境,可以细分出台地边缘礁滩相、台地边缘斜坡相,主要分布在北川通口—江油水根头,鱼洞梁—上寺—广元杨家岩—苍溪永宁铺—南江一带;从台地边缘向北主要是碳酸盐—硅质岩盆地,主要由一套中—薄层状深灰、黑灰和灰黑色的硅质岩、硅质灰岩夹极薄层泥岩组成。从构造方面来看,不同时期发育起来的深断裂及基底断裂控制着盆地的沉积格局。他们的存在进一步影响了研究区早三叠世飞仙关早期继承长兴期该区域镶边碳酸盐台地的沉积模式;而且其分布及相对升降运动对区内下三叠统沉积相的展布有着明显的控制作用。从海平面变化的影响来看,持续的海侵所造成的碳酸盐岩加积作用会促进缓坡向台地的转化,并对沉积相带的分布具有明显的影响。更多还原

【Abstract】 Sichuan Basin is an area of about 19×104km2 superimposed basins of large gas—rich natural gas resources in our country one of the regions, the former Sinian metamorphic and igneous rocks in the basement, 6000 ~ 12000m thick deposited on the sea, continental formation, is currently developing the western region to succeed in the important West—East block. But previous to the Sichuan Basin, the Early Triassic Feixianguan characteristics of rocks and sedimentary environment of the key limitations in northeastern Sichuan, western Sichuan North the strata of the research is still at an early stage of attainment is low.In this paper, the northwest Sichuan basin (ie, Northwest Territories) Lower Triassic Feixianguan object of study, field data in the field, drilling cores, logging data, based on in sedimentology, palaeontology, geophysics Principles of structural geology study and the guidance for the rock composition, biological composition, sedimentary structure, the measured profile, the deposition of a detailed analysis of such features, divided into carbonate platform depositional system and basin depositional systems, carbonate platform which depositional system study area can be identified restricted platform, open platform, platform margin facies of three types, mainly in the County to the east of the south jiange, Yilong west. Can be further divided into restricted platform, open platform, platform margin reef and platform margin slope. Platform margin depositional environment for the main study area can be broken down introduction to the edge of reef facies, platform margin slope, mainly in the North River through mouth—Jiangyou water stump, Yudong beam—the Temple—Guangyuan Yang Yan—Shop Cangxi Yongning—South River area; from the north edge of the main platform is a siliceous carbonate basin, mainly by a set of—thin layers of dark gray, dark gray and gray—black chert, siliceous limestone clip very thin mudstone composition. From the structural point of view, different periods of deep faults and has grown to basement faults controlled the basin of deposition pattern. Their presence further affected the study area, the early Triassic succession of Changxing Feixianguan rimmed carbonate platform of the regional deposition pattern; and its distribution and the relative movements of exercise on the region of the Lower Triassic sedimentary facies distribution has obvious controls. The impact of sea level change from the point of view, the continuing transgression caused by deposition of carbonate plus ramp to the platform will facilitate the transformation. Distribution of sedimentary facies and obvious impact.更多还原