本文關(guān)鍵詞： 斷坳轉(zhuǎn)換 層序地層 沉積體系 伏龍泉斷陷　出處：《中國地質(zhì)大學(xué)(北京)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：伏龍泉斷陷位于松遼盆地南部,處于中央凹陷區(qū)與東南隆起區(qū)的交界帶上,斷陷面積約1000km2,最大埋深5000m,自白堊紀(jì)以來經(jīng)歷了多個(gè)構(gòu)造演化階段,具有斷、坳雙重結(jié)構(gòu)。登婁庫組沉積時(shí)期為斷—坳轉(zhuǎn)換期,斷層活動減弱至消亡,早期同沉積斷層對沉積仍有控制作用,邊界斷層限制東部沉積范圍;晚期盆地進(jìn)入坳陷時(shí)期,同沉積斷層活動性逐漸減弱至消失,沉積范圍變大。登婁庫組厚度整體呈東厚西薄、北厚南薄的展布特征,最大沉積厚度超過700m。在登婁庫組層序地層研究方面,識別出T4、T3兩個(gè)二級層序界面及T-3m一個(gè)三級層序界面,將登婁庫組劃分為SQ1和SQ2兩個(gè)三級層序,SQ1層序識別和劃分低位域、水進(jìn)域和高位域三種體系域,SQ2層序識別和劃分出水進(jìn)域和高位域兩種體系域。研究了各三級層序在平面上的展布特征和規(guī)模,建立了垂向上由斷陷向坳陷轉(zhuǎn)換、平面上由受斷層控制到超越斷層邊界展布、沉積充填上由河流三角洲向河流相沉積轉(zhuǎn)換的層序地層模式。針對研究區(qū)鉆井和取芯較少且極不均一的難題,論文恢復(fù)了登婁庫組沉積前期的古地貌,發(fā)現(xiàn)登婁庫組沉積以前盆地存在南北兩個(gè)主要沉積中心,早期SQ1時(shí)期砂地比環(huán)洼分布,泥巖顏色在洼陷中心呈深灰色、灰色,斜坡和凸起呈棕紅色、紫色,認(rèn)為該時(shí)期盆地存在東部、東南部、南部、西南、西部五個(gè)主要物源方向,晚期SQ2砂地比呈區(qū)域性連片分布,泥巖顏色主要為棕紅色、棕褐色等氧化色,認(rèn)為該時(shí)期物源方向主要以東部為主。論文結(jié)合10口取芯井和33口井的錄井、測井及三維地震等資料,在松遼盆地伏龍泉斷陷登婁庫組識別出4種沉積相、6種亞相及10種微相。登婁庫組早期主要發(fā)育辮狀河三角洲—湖相沉積體系,西部緩坡帶和東部陡坡帶以辮狀河三角洲前緣沉積為主,北部永安洼陷區(qū)發(fā)育半深湖與滑塌沉積,南部伏南洼陷發(fā)育淺湖沉積和滑塌扇沉積。中期湖盆萎縮,伏北洼陷區(qū)以辮狀河三角洲前緣和淺湖相為主。伏南洼陷湖泊消失,以辮狀河三角洲前緣—平原為主。晚期東部邊界斷層控沉積作用明顯減弱,湖盆面積急劇萎縮,經(jīng)過填平補(bǔ)齊作用,已經(jīng)轉(zhuǎn)換為辮狀河三角洲平原—辮狀河沉積體系。
[Abstract]:The Fulongquan fault depression is located in the southern part of Songliao Basin. It is located at the junction zone between the central depression and the southeast uplift area. The fault depression covers an area of about 1000km2, with a maximum buried depth of 5000m. It has undergone several tectonic evolution stages since the Cretaceous period and is faulted. The depositional period of Denglooku formation is fault-depression transition period, the fault activity decreases to extinction, the early synsedimentary fault still controls the deposition, the boundary fault restricts the eastern sedimentary range, and the late basin enters the depression period. The activity of synsedimentary faults gradually decreases to disappear, and the sedimentary range becomes larger. The thickness of Dengloku formation is as a whole thick and thin in the east and west, and the thickness in the north is more than 700 m.The maximum thickness of the deposit is more than 700 m. In the study of sequence stratigraphy of the Denglooku formation, Two second-order sequence interfaces of T _ 4N _ 3 and T _ 3m are identified, and Denglooku formation is divided into SQ1 and SQ2 _ 3 sequence SQ1 sequences. The SQ2 sequences of three system tracts are identified and divided into two systems tracts. The distribution characteristics and scale of each third-order sequence on the plane are studied, and the vertical transition from fault to depression is established. The sequence stratigraphic model of fluvial delta to fluvial sedimentary transformation on the plane from fault controlled to outspread fault boundary is filled. In view of the problem that drilling and coring are few and very uneven in the study area, The paleogeomorphology of Denglouku formation was restored in this paper. It was found that there were two main sedimentary centers of north and south in the basin before the deposit of Denglouku formation. In the early SQ1 period, the sand and land were distributed in Bihuan depression, and the color of mudstone was dark gray and gray in the center of sag. The slope and bulge are brownish red and purple. It is believed that there are five main provenances in the basin in the east, southeast, south, southwest and west of the basin. In the late period, the SQ2 sandfield ratio was distributed in a regional sequence, and the mudstone color was mainly brownish red. The source direction of this period is mainly in the east. This paper combines the logging, logging and 3D seismic data of 10 coring wells and 33 wells. Four sedimentary facies, 6 subfacies and 10 microfacies were identified in Dengloku formation of Fulongquan fault depression in Songliao Basin. The braided river delta-lacustrine sedimentary system was mainly developed in the early stage of Denglouku formation. The west gentle slope belt and the eastern steep slope belt are mainly composed of braided river delta front sediments, the north Yongan sag develops semi-deep lake and slump deposits, the southern Funan sag develops shallow lake deposits and sloughing fan deposits, and the lake basin shrinks in the middle period. In Fubei depression, braided river delta front and shallow lacustrine facies are dominant. The lake in Funan sag disappears, and braided river delta fore-plain is the main one. In the late period, the fault-controlled sedimentation of the eastern boundary is obviously weakened, and the lake basin area shrinks sharply. It has been transformed into braided river delta plain-braided river sedimentary system.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P539.2;P618.13

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