【作者】 白斌；

【导师】 周立发；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2008， 博士

【摘要】 准噶尔南缘山前带及其邻区作为中国中西部前陆盆地的重要组成部分,已经成为中国西部油气勘探的热点地区和前沿领域。但由于大地构造位置特殊,分别受到海西、印支、燕山和喜马拉雅多期次不同构造体系的复合与叠加以及同期次不同构造体系的联合与制约,使其最终成为一个以晚古生代、中新生代陆相沉积为主体的复合叠加盆地。特别是喜山期强烈构造改造作用使研究区成为油气勘探的复杂区。因此,对研究区的构造演化与油气聚集进行深入研究,将有助于确定研究区不同阶段成盆作用及改造作用的动态过程,为更好地对准噶尔南缘油气资源及勘探目标进行客观评价提供充足的证据。论文以沉积盆地动力学理论为指导,以构造沉积综合分析为研究手段,以地面地质、井下地质、地球物理、地球化学方法和各种分析测试资料为基础,以成盆作用及改造作用的动态过程为主线,深入开展了研究区及邻区晚石炭世以来构造特征、不同构造旋回的盆地原型、中新生代构造转换关键时刻(或界面)的构造变形及其三维结构形式以及与油气聚集关系的研究。研究区岩石地球化学与地球物理资料的综合研究表明:准噶尔盆地存在三重基底-前寒武纪古老结晶基底、晚加里东褶皱基底和华力西期的褶皱基底。晚石炭世以来的构造特征研究表明:中二叠世末、早三叠世末、晚三叠世末、中侏罗世巴柔期末、晚侏罗世末、早白垩世末和中新世末是北天山造山带与准噶尔盆地南缘构造体制发生根本性转变的关键时刻。据此将研究区构造层划分为:晚海西构造层、印支构造层、燕山构造层和喜马拉雅构造层。其中准噶尔南缘前陆盆地和北天山地区陆内造山-成盆作用的构造形成主要发生在中新生代,但以喜马拉雅期为主。将研究区划分为博格达山前冲断带、伊山山前冲断带、四棵树凹陷、阜康凹陷、昌吉凹陷与三台凸起等基本构造单元。博格达山前冲断带主体为一逆冲推覆体,喜山期是该构造带的最终定型期;伊山山前冲断带可划分为以厚皮构造为特征的伊山前缘断褶带和以薄皮构造为特征的伊山山前滑脱带,并对其基本构造样式和成因机理进行了深入讨论。在古硫、物源、砂岩碎屑模型、碎屑岩地球化学、碎屑岩重矿物组合等特征研究的基础上,对研究区晚石炭世以来不同构造期次的盆地原型进行了深入研究,明确提出:晚石炭世-中二叠世盆地具陆内裂谷盆地类型,晚二叠世-早三叠世盆地为冲断山前坳陷盆地,中晚三叠世盆地为准平原化型的坳陷盆地,早中侏罗世盆地为弱伸展构造背景下的坳陷盆地,中晚侏罗世盆地为冲断山前坳陷盆地,白垩纪-中新世盆地为稳定坳陷盆地和上新世-第四纪盆地为强烈冲断前陆坳陷盆地,并对不同构造期次原始盆地的构造沉积格局进行了探讨和恢复。通过对喜山期构造特征与油气聚集关系的研究,认为研究区具备三套有利生储盖组合,即二叠系-三叠系的下部成藏组合、侏罗系-白垩系的中部成藏组合和白垩系-新近系的上部成藏组合。中新生代构造应力晨刂葡碌囊约坛行缘募费棺饔梦鞯墓乖旎疃怯跋煅芯壳推钪站奂氤刹氐墓丶蛩亍更多还原

【Abstract】 As important component of foreland basin of Central-western China, piedmont structural zone of south margin of Junggar and adjacent area have became the research focus and frontier field. Because of special tectonic position, superimposed and restricted respectively by structure system of multi-stages and synch-stages of Variscan period, Indosinian period, Yanshan period and Himalaya period, margin of Junggar and adjacent area finally became a composite superposition basin, mainly composed of continental deposit of late Paleozoic and Meso-Cenozoic. By the research of the relation between tectonic evolution and enrichment of hydrocarbon, it is conduced to confirm the dynamic process of basin formation action and transformation action of different stage, and provide the sufficient evidence for objective evaluation of the hydrocarbon resource and exploration object optimize.Guided of the dynamics theory of sedimentary basin, approached of the structure-sedimentary research, based on the surface geology, underground geology, geophysical, geochemistry and various analyzing and testing data, mainlined on basin formation action and transformation action, structure character, basin prototype of difference cycle, the structure deformation and 3D structure form and the relation to the enrichment of hydrocarbon of the key time of Meso-Cenozoic are being studied deeply.According to the rock geochemistry and geophysical data, it shows that there are triple basements in Juggar basin: ancient ctystallization basement of Precambrain, folded basement of late-Caledonian and folded basement of Variscan. The structural character since late Carboniferous indicates that there are seven critical moments of tectonic regime conversion between north Tianshan and south margin of Juggar: end of the middle Permian, end of the early Triassic, end of late Triassic, end of Bajocian stage of middle Jurassic, end of late Jurassic, end of early Cretaceous and end of Miocene. Based on critical moments, tectonic sequence in the study area can be divided into four: tectonic sequence of late Variscan period, Indosinian period, Yanshan period and Himalaya period.The main formation time for foreland basin of south margin of Juggar and inner continental orogen-basin formation of north Tianshan area is Himalaya period of Meso-Cenozoic. Tectonic units in the study area can be divided into six parts: Bogda piedmont thrust belt, Yishan piedmont thrust belt, Sikeshu depression, Fukang depression, Changji depression and Santai depression. Bogda piedmont thrust belt is an overthrust nappe, formed in Himalaya period. Yishan piedmont thrust belt is subdivided into two parts: fault-fold belt of Yishan front characteristic of thick-skinned structure and decllement zone of piedmont of Yishan characteristic of thin-skinned structure. Sikeshu depression is divided into three parts: monocline in the south, fold belt in the middle and monocline in the north. According to the basin prototype, tectonic stage can be divided into eight: continent rift vally stage from late Carboniferous to Middle Permian, thrust depression stage from early Permian to early Triassic, concentrating stage in mid-late Triassic, weak extension stage in early-middle Jurassic, thrust depression stage in mid-late Jurassic, depression stage in Cretaceous, steady depression stage from Paleocene to Miocene, the formation stage of intense overthrust belt and foreland basin form Pliocene to Quaternary.According to the relation between structure of Himalaya stage and enrichment of hydrocarbon, three sets of source reservoir cap assemblage are divided: lower assemblage from Permian to Triassic, middle assemblage from Jurassic to Cretaceous, upper assemblage from Cretaceous to Neogene. The tectonic activity of Mio-Cenozoic characteristic of inheritance squeezing action is the main element for hydrocarbon enrichment and reservoir forming.更多还原