【作者】 李玮；

【导师】 柳益群；

【作者基本信息】 西北大学 ， 岩石学、矿物学、矿床学， 2004， 硕士

【摘要】 本文以陆相层序地层学的基本理论和研究方法，在前人大量工作的基础上，对新疆三塘湖盆地层序地层学做了初步讨论和分析，并取得了一些认识。 三塘湖盆地隶属于新疆北部地区，位于西伯利亚板块和哈萨克斯坦板块碰撞结合部位，夹持于两条古生代缝合带之间，属叠置在古生代造山带之上，以发育二叠纪—中新生代陆相沉积为特点的上叠盆地，具有前二叠纪火山岩—碎屑岩褶皱基底。盆地的形成和演化可概括为三个阶段，即二叠纪陆内断陷盆地发育阶段；三叠—白垩纪拗陷盆地发育阶段；新生代逆冲造山和盆地改造阶段。 在大量地震剖面解释、现有的钻井资料、古生物和测年资料的基础上，从层序地层学角度将三塘湖盆地地层进行优化厘定，统一了地层划分中的认识。 根据地震剖面、测井曲线、古生物和岩心资料所反映的盆地地层之间的接触关系及层序地层的发育特征，建立了三塘湖盆地二叠纪—侏罗纪层序地层格架。 依据三塘湖盆地构造演化不同阶段盆地性质的不同，以三塘湖盆地基底不整和面、晚海西期形成的区域性不整合面和晚燕山期形成的区域性不整合面将沉积盖层划分为三个一级充填层序，分别为二叠纪断陷盆地充填层序、三叠—白垩纪拗陷盆地充填层序和新生代冲断拗陷盆地充填层序。依据次一级不整合面和沉积旋回将断陷盆地充填层序划分为一个构造层序、三个沉积层序，拗陷盆地充填层序划分为三个构造层序和7个沉积层序。 二叠纪断陷盆地沉积体系经过多期构造叠加改造，现今表现为残留盆地，地层发育不全，现今残留三个三级层序，分别相当于下二叠统卡拉岗组、中二叠统芦草沟组和条湖组，其层序发育特点为：湖盆沉积中心地带缺失或不发育低水位体系域，湖盆边缘地带低水位体系域发育，该体系域沉积物主要为滨浅湖相水下重力流沉积和白云岩沉积，具小型进积式叠加样式；水进体系域沉积物主要为半深湖相凝灰质泥岩和白云质泥岩，具退积式叠加样式；高水位体系域主要是滨浅湖相沉积体系，具加积式和进积式叠加样式。 三叠纪—侏罗纪拗陷盆地层序地层发育较全，整个盆地缺失下三叠统，马朗凹陷还缺失下侏罗统，大部分地区缺失中三叠统。层序地层发育特点为：低水位体系域主要发育低位重力流沉积、辫状河沉积、冲积扇沉积和水进型三角洲沉积；水进体系域主要发育湖相泥岩，在湖盆边缘带发育退积型沉积体系；高位体系域主要发育滨浅湖相、曲流河相及水退型三角洲沉积体系。 通过综合分析三塘湖盆地层序地层形成发育特点，认为二叠纪断陷盆地油气主要聚集在低位湖盆边缘地带和高位湖盆中心地带，三叠一侏罗纪拗陷盆地油气主要聚集在低位盆地中心地带。 由于后期特别是晚海西期区域挤压运动对断陷盆地的改造，晚燕山期区域挤压运动对拗陷盆地的挤压改造，油气运移和储存条件相应的发生了变化，二叠纪断陷盆地油气主要聚集在盆地南部逆冲推覆前缘带和北部单斜带内;三叠纪一白至纪拗陷盆地油气主要分布在条湖拗陷南部逆冲推覆前缘带、北部单斜带内和马朗拗陷中部地带。更多还原

【Abstract】 This thesis has studied primitively continental sequence stratigraphy of Santanghu basin with the fundamental principle and methods of classic sequence stratigrahy, and got some elementary conclusions.Santanghu basin, located in the joint between the kazakhstanian plate and the Siberian plate, has the pre-Permian folded basements of volcanic-sedimentary rocks. The Santanghu basin has three formation and evolution stages, i.e. formation and evolution stage of fault-depression basin in Permian, formation and evolution stage of depression basin in Triassic-Jurassic-Cretaceous, formation and evolution of Neozoic basin.This paper provides a new understanding on strata in Santanghu Basin through sequence stratigraphic technique, with lots of seismic section.According to the synthetical study of seismic section, well logging, sampling data, sediment system, character of sediment filling, the sequence stratigraphic framework has been set up during the Permian to Jurassic in the Santanghu basin, which include two basin-fill sequence which are fault depression basin-fill sequence of the Permian, and depression basin-fill sequence of Trials-Jurassic. The fault depression basin-fill sequence of the Permian can be divided into 3 sequences. The depression basin-fill sequence of Trias-Jurassic can be divided into 3 tectonic sequences, which include 7 sequences.In the fault depression basin of the Permian, the LST runs short of in the heartland of the lake, however, it is abundant in lakeshore area, it is mainly comprised of underwater gravity sediments and dolomite sediments of shallow lake facies. Vertically, LST consists of small scale progradational or aggradational parasequence sets; whereas, TST is comprised of mudstone of tuff and dolomitic mudstone of semi-deep lake facies in the area of lake basin, retrogradational delta complex can be found at the marginal region of the basin; HST is mainly comprised of shallow lake facies sediments system, with aggradational and progradational parasequence set stacking pattern.In the depression basin of Trias-Jurassic, LST consists of sediment gravity flow, alluvial fan-braided river sediments and (fan) delta-lacustrine facies sedimentary systems, with small scale progradational or aggradational parasequence sets; TST mainly consists of mudstone of lake, with retrogradational parasequence sets; HST is mainly comprised of shallow lake facies sediments systems, meandering riversedimentary systems and progradational delta sedimentary systems, with aggradational and progradational parasequence set stacking pattern.It concluded that oil and gas is distributed in the margin of lake in LST and in the heart area of lake in HST; whereas, it is distributed in the heart area of basin in LST.Affected by the regional pressing role in late Hercynian and the late Yanshan and Himalayas movement, oil & gas accumulation had changed in basin. Oil & gas is mainly located in the front of the southwest thrust and nappe tectonic belt and north side of syncline in the fault depression basin of the Permian. Of course, it mainly located in the southwest thrust and nappe tectonic belt and north side of syncline in the Tiaohu depression, and in the heart area of Malang depression.更多还原