塔里木盆地东南缘侏罗系中下统层序地层与沉积演化

发布时间：2018-03-05 17:07

本文选题：阿尔金　切入点：层序地层　出处：《新疆大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文在全面总结前人研究成果基础上,以阿尔金以北的塔里木盆地东南缘为研究区域,利用野外露头剖面、测井、地震、古生物等资料,以层序地层学理论为指向,针对塔东南6口钻井4个煤矿及野外露头剖面进行了层序划分和沉积体系的研究,将研究区划分出2个二级层序及5个三级层序,并按低位域、湖侵域和高位域将每个层序三分,其中SQ1SQ2相当于J1s,SQ3相当于J1k,SQ4SQ5相当于J2y和J2t。通过野外露头剖面观察、识别岩心建立典型沉积相序列,结合地震相及测井沉积相研究,识别主要沉积相类型。结果表明,侏罗系中下统主要发育冲积扇、扇三角洲、湖泊及沼泽4种沉积体系。认为自早侏罗世至中侏罗世,由南部西昆仑山物源区至研究区,沉积相带以冲积扇—滨浅湖相逐渐过渡。早侏罗世时期,盆地处于断陷初期,沉积范围较小,沉积粒度相对较大,莎里塔什组以冲积扇、冲积平原及滨浅湖相沉积为主。中侏罗世时期,盆地向断坳—坳陷过渡,沉积范围增大,湖平面上升,沉积相带依旧以冲积扇—湖泊过渡,出现扇三角洲平原及扇三角洲前缘亚相,沉积中心位于民丰凹陷及瓦石峡凹陷处。在此基础上,通过对层序-沉积充填控制因素的分析,认为沉积相带的展布格局受构造控制,研究区侏罗系沿山前呈NEE向狭长带状展布,沉积中心位于民丰凹陷及瓦石峡凹陷一带,物源区为南部东昆仑山。
[Abstract]:On the basis of summing up the previous research results, this paper takes the southeastern margin of Tarim Basin north of Altun as the research area, using outcrop profile, logging, earthquake, paleontology and other data, and taking sequence stratigraphy theory as the direction. The sequence division and depositional system of 4 coal mines and outcrop profiles in 6 wells in southeast of Tarim are studied. The study area is divided into two secondary sequences and five third-order sequences, and according to the low position region, the study area is divided into two secondary sequences and five third-order sequences. Each sequence is divided into three parts in the lake transgression region and the high level area, where SQ1SQ2 is equivalent to J1kGN SQ3, equivalent to J1knSQ4SQ5 equivalent to J2y and J2t.Through field outcrop profile observation, typical sedimentary facies sequences are identified and typical sedimentary facies sequences are established in the cores, which are studied in combination with seismic facies and logging sedimentary facies. The main sedimentary facies types are identified. The results show that four sedimentary systems, alluvial fan, fan delta, lake and swamp, are mainly developed in the middle and lower Jurassic. It is considered that from the early Jurassic to the middle Jurassic, from the source region of the western Kunlun Mountains in the south to the study area, In the early Jurassic period, the basin was in the early stage of fault depression, the sedimentary range was relatively small, the grain size was relatively large, and the alluvial fan was used in the Shalitash formation, and the sedimentary facies zone was gradually transitioning from alluvial fan to shallow lacustrine facies. During the Middle Jurassic period, the basin transitioned to fault-depression, the sedimentary area increased, the lake level rose, and the sedimentary facies zone was still alluvial fan-lake transition. The fan delta plain and fan delta front subfacies appear, and the sedimentary center is located in Minfeng sag and Washixia sag. Based on the analysis of the controlling factors of sequence and sedimentary filling, it is concluded that the distribution pattern of sedimentary facies belt is controlled by structure. The Jurassic in the study area is distributed along the front of the mountain in the NEE direction. The sedimentary center is located in the area of Minfeng Sag and Washixia Sag, and the source area is the East Kunlun Mountains in the south.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P534.52

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