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1.
塔里木盆地古生代重要演化阶段的古构造格局与古地理演化   总被引:14,自引:4,他引:10  
塔里木盆地在古生代经历了中-晚奥陶世、晚奥陶世末、中泥盆世末等多个重要的盆地变革期,形成了多个重要的不整合,盆地构造古地理发生了重要的变化。中、晚奥陶世盆地的变革形成了由巴楚古斜坡-塔中隆起-和田河隆起构成的大型古隆起带、相对沉降的北部坳陷带以及由于挤压挠曲沉降形成的塘古孜巴斯坳陷带。中部古隆起带制约着晚奥陶世东窄西宽的弧立碳酸盐岩台地体系的发育,而开始形成于震旦纪的满加尔拗拉槽及东南侧的塘古孜巴斯坳陷接受了巨厚的中、晚奥陶世重力流沉积。奥陶纪末的盆地变革形成了北东东向展布的西南-东南缘和西北缘的强烈隆起带,总体的古构造地貌控制着早志留世北东东向展布的滨浅海陆源碎屑盆地的沉积格局。中泥盆纪世末期的盆地强烈隆升并遭受了夷平化的剥蚀作用,形成了大范围分布的角度不整合面,并以塔北隆起和塔东隆起的强烈抬升为显著特征。盆地古构造地貌从东低西高转为东高、西低,制约着晚泥盆和早石炭世由东向西南方向从滨岸到浅海的古地理分布。中、晚奥陶世主要不整合及其剥蚀量的分布反映出北昆仑向北碰撞和挤入是造成盆地南缘、东南缘及盆内隆起的主要原因。南天山洋的俯冲、碰撞在奥陶世末至早志留世已对盆地西北缘产生影响,导致塔北英买力隆起的抬升和遭受剥蚀。  相似文献   

2.
Tarim Basin is the large, very complex, oil-bearing basin in China, surrounded by the Tianshan–Beishan, West Kunlun and Altyn Tagh mountain belts to the north, south, and southeast, respectively. Understanding the processes and evolution of this complex superimposed basin, especially with respect to the effects of single tectonic movements, is a difficult challenge, which concerns the tectonic and dynamic interrelationships between the basin and the orogenic belts during the different stages of the Paleozoic in the Paleo-Asian and Tethyan tectonic systems and for the evaluation of the resource potentials in Tarim Basin. In this study, we focused on 3-dimensional, basin-scale structural architecture and the properties of two regional unconformities that occur within the basin and its adjacent areas. Here, we outline the structural deformations underlying the unconformity, the structural architecture styles and the distributions of the unconformity, and the stratigraphic sequence and nature of the sedimentary rocks immediately overlying the unconformity. During the late Early and Middle Paleozoic tectonic movements, disconformities developed mainly in the northern and the central parts of the basin, and angular unconformities which beneath layers were monocline and faulted-fold deformations developed in the southern, or the southern and northern parts of the basin, respectively. Before the Silurian, the Low Hotian Uplift, the NE-trending faulted-folded belts of the Tangguzibas Depression and the southern Tazhong Uplift underwent intense deformation related to SE–NW-directed tectonic compression. In addition, the NE-trending faults in the Tangguzibas Depression developed during periods of activity on the South Altyn Tagh Fault. The structural deformation, as well as the depositional facies, formed in response to the subduction and closure of the South Altun Ocean and West Kunlun–Kudi Ocean, and the resulting collisional orogeny. Prior to deposition of Upper Devonian sediments, structural deformation and erosion occurred in two marginal parts of the basin. The extent and intensity of deformation on the NE-trending faults in the Tangguzibas Depression were also reduced, whereas the NE-trending folds developed in the Manjiaer Depression. The Tabei Uplift experienced uplift and deformation. The closure of the North Altun Ocean and the eastern part of the South Tianshan Ocean with south-subduction may be the main driving forces for the tectonic activity. Extensive areas in the northern and southern margins of the basin were uplifted and denudated by orogenic activity as a prelude to the molasse basin that developed in the early Late Devonian in the northeastern and southeastern parts of the basin. The structural architecture of the unconformities reveals the geometry and dynamics of the basin–orogen system in single tectonic movements.  相似文献   

3.
The Tarim Basin has experienced three tectonic evolutionary phases from the Cambrian to Ordovician: (1) Regional extension from the late Neoproterozoic to Mid-Early Cambrian, (2) Relatively weak regional compression from the Late Cambrian to Mid-Early Ordovician, and (3) Regional compression during the Late Ordovician. Intra-platform tectonic and sedimentary characteristics indicate a clear linkage to the tectonic evolution of the basin margin during early Paleozoic time. During the Cambrian, small intra-platform rift-related depressions formed during an extensional setting. During the Mid-Early Ordovician, a transition from extension to compression caused formation of the Tazhong and Tabei paleo-uplifts and major unconformities T74 (base of the Late Ordovician). The evolving paleo-geomorphology led to differentiation of sedimentary facies, and numerous intra-platform shoals formed during deposition of the Early Ordovician Yingshan Formation. During the Late Ordovician, regional compression began, which changed the platform margin slopes into four slopes that surrounded the three isolated island uplifts of Tabei, Tazhong, and Tangnan in the Late Ordovician. Simultaneously, the basin margin dynamic conditions also changed the relative sea level and filling pattern of the basin. In the Early and Middle Cambrian, the Tarim Basin mainly developed a progradational ramp-type platform due to relative sea level fall. From the Late Cambrian to Early Ordovician the relative sea level began to rise, resulting in an aggradational—retrograding rimmed margins-type platform. In the Late Ordovician, along with a further rise in relative sea level, the basin mainly developed isolated platform.  相似文献   

4.
塔东南隆起沉积-构造特征及其演化历史   总被引:1,自引:0,他引:1       下载免费PDF全文
基于地震剖面、岩心、测井和露头剖面等资料分析,运用平衡剖面复原技术,论述了塔里木盆地塔东南隆起带古生代以来的沉积-构造特征及其演化历史.在地震剖面上识别出6个地层不整合界面,划分了5个主要地层构造层序.指出塔东南隆起形成于晚奥陶世加里东运动,经历了加里东、海西、印支、燕山和喜山多次构造运动,在中生代以陆内变形为主,受到南北两条主边界断裂的控制,于中生代早期发生伸展断陷,并遭受晚新生代喜山运动的强烈挤压改造,形成了现今两凹两凸的构造格局.  相似文献   

5.
重新划分塔里木盆地塔北隆起的次级构造单元   总被引:6,自引:3,他引:3  
塔北隆起位于塔里木盆地北部,是塔里木盆地油气最富集的构造单元之一.其在古生代克拉通内古隆起的基础上,于二叠纪末-三叠纪早期定型为库车周缘前陆盆地的前缘隆起.新生代,其整体沉降,成为埋藏于北塔里木陆内前陆盆地前渊下的一个残余古隆起.目前通用的塔北隆起构造单元划分方案不能准确反映其真实的构造格局.根据最新的研究成果,我们建议重新划分塔北隆起构造单元:(1)取消哈拉哈塘凹陷和草湖凹陷,重新定义轮南低凸起.重新定义的轮南低凸起包括原轮南低凸起、哈拉哈塘凹陷和草湖凹陷北部,是一个下古生界大型鼻状背斜构造,形成于前石炭纪;原草湖凹陷南部划归北部坳陷.(2)以中奥陶统顶面海拔约-6500m的等高线作为塔北隆起的南部边界,该等高线较好地反映了塔北隆起南部的构造轮廓,特别是轮南大型鼻状背斜构造的轮廓.(3)以羊塔1-英买8断裂和英买4-英买1背斜组成的一条较清晰的古生界构造线划分轮台凸起和英买力低凸起.此界线两侧,古生界各反射层存在陡然、明显的落差,岩浆作用、地层发育、构造变形和演化历史存在明显差异.重新划分的塔北隆起包括库尔勒鼻状凸起、轮台凸起、轮南低凸起、英买力低凸起和温宿鼻状凸起五个次级构造单元.本文给出了塔北隆起及其各次级构造单元清晰的定义和范围,并简单论述了其形成演化过程.  相似文献   

6.
盆地原型研究有助于恢复盆地构造-岩相古地理和揭示盆山耦合,对油气勘探具有重要的指导意义。文中利用最新的钻井、地震及露头资料,以沉积相为研究实体,运用盆-山结合的思路,由点→线→面进行分析,重建了塔里木盆地中奥陶世一间房组沉积时期的构造-沉积环境,研究了原型盆地特征及性质。一间房组沉积时期,巴楚—塔中和塘南台内隆起为暴露剥蚀区;顺南—塘古巴斯—玉东台内洼地区发育低能的泥晶灰岩相;塔北和古城台地区发育大面积的台内颗粒滩相;柯坪台盆区发育深水瘤状灰岩—黑色页岩相;塔东深水盆地区经历了黑色页岩相→陆源碎屑浊积岩相的演变;库鲁克塔格—罗西台地区为继承发育的开阔台地相。该时期塔里木盆地构造-沉积格局具有由早奥陶世东西分异的台盆格局向晚奥陶世南北分异的隆坳格局过渡的特征,表现为塔西台地古地貌的分异和塔东深水盆地沉积性质的反转。该时期塔里木盆地整体具有克拉通内拗陷与边缘拗陷复合的性质,但在塔西克拉通内坳陷的南部叠加了前陆盆地的性质(塘南前隆和顺南—塘古巴斯—玉东后隆坳陷),在其西北部叠加了裂陷盆地的性质(柯坪克拉通边缘裂陷)。该时期塔里木盆地构造-沉积环境与原型盆地特征是其对周缘大地构造运动的响应。  相似文献   

7.
古亚洲洋不是西伯利亚陆台和华北地台间的一个简单洋盆,而是在不同时间、不同地区打开和封闭的多个大小不一的洋盆复杂活动(包括远距离运移)的综合体.其北部洋盆起始于新元古代末-寒武纪初(573~522Ma)冈瓦纳古陆裂解形成的寒武纪洋盆.寒武纪末-奥陶纪初(510~480Ma),冈瓦纳古陆裂解的碎块、寒武纪洋壳碎块和陆缘过渡壳碎块相互碰撞、联合形成原中亚-蒙古古陆.奥陶纪时,原中亚-蒙古古陆南边形成活动陆缘,志留纪形成稳定大陆.泥盆纪初原中亚-蒙古古陆裂解,裂解的碎块在新形成的泥盆纪洋内沿左旋断裂向北运动,于晚泥盆世末到达西伯利亚陆台南缘,重新联合形成现在的中亚-蒙古古陆.晚古生代时,在现在的中亚-蒙古古陆内发生晚石炭世(318~316Ma)和早二叠世(295~285Ma)裂谷岩浆活动,形成双峰式火山岩和碱性花岗岩类.蒙古-鄂霍次克带是西伯利亚古陆和中亚-蒙古古陆之间的泥盆纪洋盆,向东与古太平洋连通,洋盆发展到中晚侏罗世,与古太平洋同时结束,其洋壳移动到西伯利亚陆台边缘受阻而向陆台下俯冲,在陆台南缘形成广泛的陆缘岩浆岩带,从中泥盆世到晚侏罗世都非常活跃.古亚洲洋的南部洋盆始于晚寒武世.此时,华北古陆从冈瓦纳古陆裂解出来,在其北缘形成晚寒武世-早奥陶世的被动陆缘和中奥陶世-早志留世的沟弧盆系.志留纪腕足类生物群的分布表明,华北地台北缘洋盆与塔里木地台北缘、以及川西、云南、东澳大利亚有联系,而与上述的古亚洲洋北部洋盆没有关连,两洋盆之间有松嫩-图兰地块间隔.晚志留世-早泥盆世,华北地台北部发生弧-陆碰撞运动,泥盆纪时,在松嫩地块南缘形成陆缘火山岩带,晚二叠世-早三叠世华北地台与松嫩地块碰撞,至此古亚洲洋盆封闭.古亚洲洋的南、北洋盆最后的褶皱构造,以及与塔里木地台之间发生的直接关系,很可能是后期的构造运动所造成的.  相似文献   

8.
Silurian sandstone in Tarim Basin has good reservoir properties and active oil and gas shows, especially thick widely-distributed bituminous sandstone. Currently, the Silurian was found containing both bitumen and conventional reservoirs, with petroleum originating from terrestrial and marine source rocks. The diversity of their distribution was the result of "three sources, three stages" accumulation and adjustment processes. "Three sources" refers to two sets of marine rocks in Cambrian and Middle-Upper Ordovician, and a set of terrestrial rock formed in Triassic in the Kuqa depression. "Three stages" represents three stages of accumulation, adjustment and reformation occurring in Late Caledonian, Late Hercynian and Late Himalayan, respectively. The study suggests that the Silurian bitumen is remnants of oil generated from Cambrian and Ordovician source rocks and accumulated in the sandstone reservoir during Late Caledonian-Early Hercynian and Late Hercynian stages, and then damaged by the subsequent two stages of tectonic uplift movements in Early Hercynian and Pre-Triassic. The authors presumed that the primary paleo-reservoirs formed during these two stages might be preserved in the Silurian in the southern deep part of the Tabei area. Except for the Yingmaili area where the Triassic terrestrial oil was from the Kuqa Depression during Late Himalayan Stage, all movable oil reservoirs originated from marine sources. They were secondary accumulations from underlying Ordovician after structure reverse during the Yanshan-Himalayan stage. Oil/gas shows mixed-source characteristics, and was mainly from Middle-Upper Ordovician. The complexity and diversity of the Silurian marine primary properties were just defined by these three stages of oil-gas charging and tectonic movements in the Tabei area.  相似文献   

9.
塔里木地块与古亚洲/特提斯构造体系的对接   总被引:32,自引:15,他引:17  
塔里木盆地为环形山链所环绕,北缘为古亚洲体系的天山弧形山链,南缘为特提斯体系的西昆仑-阿尔金弧形山链。自新元古代晚期以来,塔里木地块及周缘地区经历了古亚洲洋盆和特提斯洋盆的开启、俯冲、闭合以及微陆块多次碰撞造山,发生多期的构造、岩浆及成矿作用。特别是受印度/亚洲碰撞(60~50Ma)以来的近程效应和远程效应影响,使塔里木盆地周缘发生强烈的隆升、缩短及走滑变形,形成了现今复杂的环型造山系,完成了古亚洲体系和特提斯体系与塔里木地块的最终对接。塔里木地块与周缘两大构造体系的焊接是从早古生代开始的。研究表明,早古生代末期塔里木已与西昆仑-阿尔金始特提斯造山系链接一起。此时,塔里木地块东段与中天山增生弧地体碰撞,而西段在晚古生代与中天山增生弧地体碰撞。塔里木盆地周缘早古生代造山系中存在早古生代中期和早古生代晚期的两次造山事件,致使塔里木盆地内映现两个早古生代构造不整合面:晚奥陶世-志留纪之间的角度不整合和中晚泥盆世与早古生代之间的角度不整合。塔里木盆地早古生代的古地理、古环境和古构造研究表明,塔里木早古生代台地位于盆地的中西部,盆地东部为陆缘斜坡和深海/半深海沉积盆地,与南天山早古生代被动陆缘链接。印度/亚洲碰撞导致塔里木盆地西南缘的喜马拉雅西构造结的形成与不断推进,使特提斯构造体系与古亚洲构造体系在西构造结处靠拢及对接,终使塔里木盆地最后定型。  相似文献   

10.
The Late Devonian‐Early Carboniferous Mansfield Basin is the northernmost structural sub‐basin of the Mt Howitt Province of east‐central Victoria. It is comprised predominantly of continental clastic sedimentary rocks, and is superimposed upon deformed Cambrian to Early Devonian marine sequences of the Palaeozoic Lachlan Fold Belt. This paper documents evidence for synsedimentary deformation during the early history of the Mansfield Basin, via sedimentological, structural and stratigraphic investigations. Repeating episodes of folding, erosion and sedimentation are demonstrated along the preserved western margins of Mansfield Basin, where fold structures within the lower sequences are truncated by intrabasinal syntectonic unconformities. A convergent successor basin setting (an intermontane setting adjacent to, or between major fault zones) is suggested for initial phases of basin deposition, with synsedimentary reverse faulting being responsible for source uplift and subsequent basin deformation. Palaeocurrents within conglomerate units indicate derivation from the west and are consistent with episodic thrusting along basin margin faults providing elevated source regions. Periods of tectonic quiescence are represented by finer grained meandering fluvial facies (indicative of lower regional topographic gradients) which display drainage patterns that appear not to have been influenced by bounding faults to the west. An up‐sequence increase in the textural and compositional maturity of basin sandstones and conglomerates is proposed to be a result of the incorporation of basin fill into ongoing basin deformation, with unstable metapelitic rocks being progressively winnowed from clast populations. Rather than resulting from Carboniferous (Kanimblan) reactivation of extensional structures, as is generally assumed, the deformation observed within the lower units of the Mansfield Basin is suggested here to be essentially syndepositional and at least Late Devonian in age.  相似文献   

11.
对塔里木盆地塘古兹巴斯凹陷志留系与奥陶系(S/O3)、上泥盆统与志留系(D3d/S)2个区域角度不整合的三层结构特征及属性进行详细研究,分析了不整合面下构造变形特征、不整合面结构类型分布、不整合面上初始沉积砾岩成分及其物源.发现加里东中期该区形成了塔里木盆地独特的不整合结构,构造不整合(S/O3)明显地受北东东-南西西走向逆冲断裂系控制,在凹陷北部逆冲断裂系上盘发育中等角度单斜不整合和褶皱不整合,沿断裂带形成了多个角度不整合带;加里东晚期不整合(D3 d/S)区域上呈现由南向北的剥蚀特征,局部受继承性再活动的断裂控制存在北东东向的中角度单斜不整合带,且构成了加里东中期及晚期的叠合不整合.两期不整合面上的初始沉积砂砾岩有明显差异,加里东中期不整合面上初始沉积以近源的沉积岩为主、物源来自被动大陆边缘;晚期不整合面上的初始沉积砾岩主要为硅质岩和变质岩,物源主要来自较远的被动大陆边缘及大陆岛弧.综合分析表明,晚奥陶世末塘古兹巴斯凹陷主要受到阿尔金、西昆仑的构造作用;中志留世-晚泥盆世主要受到西昆仑及阿尔金碰撞造山活动共同作用.在加里东构造运动中晚期,凹陷中控制不整合发育的NEE向逆冲断裂系与南阿尔金断裂在活动时限、强度、区域应力场上具有可比性.加里东中、晚期不整合的三层结构及其属性是反映阿尔金-西昆仑早古生代构造运动发生、发展、终结动态演化过程的良好证据.  相似文献   

12.
广西钦防海槽迁移与沉积-构造转换面   总被引:13,自引:0,他引:13       下载免费PDF全文
广西的钦州-防城-带,素以钦防海槽称之,系指加里东期构造运动后,扬子与华夏陆块间的“残留海”。其两侧为古隆所夹持,西为大明山古隆起,东为云开大山古隆起,其间划分为四个构造单元,由东向西依次为:博白坳陷,六万大山隆起,钦州坳陷和十万大山坳陷。现构造形迹的排列,反馈防海槽在早古生代至中生代间深海盆或浅海深水盆地在构造和沉积上有自东向西迁移的特点。晚古生代盆地迁移过程至少有八个沉积-构造转换面可记录盆地的构造演化:第1转换面为早奥陶世与晚寒武世间的沉积界面;第2转换面为早志留世与晚奥陶世间的沉积界面;第3转换面为早泥盆世早期与晚志留世间的海侵上超面;第4转换面为中泥盆世的海侵上超面;第5转换面为中二叠世与晚二叠世间的沉积界面;第6转换面为早三叠世的海侵面;第7转换面为中晚三叠世与早三叠世间的沉积界面;第8转换面为早侏罗世与晚三叠世间的沉积界面。前两个界面为盆山转换面,与华南加里东构造运动过程相耦合,为挤压的构造背景;第3界面为水下间断面,下泥盆统与上志留统为不连续沉积,在构造上应是挤压机制下的破裂不整合,也是加里东期构造运动的响应;第4界为海西期的海侵上超面,与盆地走滑拉张同步;第5界面则反馈于印支期造山的初始阶段,第6界面为中生代盆地迁移转换面;第7界面为印支期造山过程的盆地转换面;第8界面为燕山期造山造盆转换面。其转换面性质的转化,代表钦防海槽可能是个复杂大陆边缘前陆盆地演化史。  相似文献   

13.
通过地表露头及钻井取心的浊积岩沉积特征观察及古流向分析、砂岩主量元素化学成分分析及地震相分析,提出塔里木盆地奥陶系陆源碎屑浊积岩主要发育于塔东地区及塘古兹巴斯坳陷的上奥陶统之中,其浊流沉积物源主要来自盆地东南侧的阿尔金岛弧、其次来自盆地西南侧的库地活动陆缘隆起;仅盆地东北缘却尔却克山地区出露的中奥陶统顶部的却尔却克组下部陆源碎屑浊积岩的物源区,主要来自其北侧的库鲁克塔格被动陆缘隆起(台地隆起剥蚀区)。综合分析认为,晚奥陶世发生于板块南缘的阿尔金岛弧及库地活动陆缘隆起与塔里木板块的碰撞挤压运动产生的大量陆源碎屑物源,导致了板块内部多个孤立碳酸盐台地的逐步消亡及板块南部浊流盆地群的形成。  相似文献   

14.
塔里木盆地早古生代晚期构造-沉积响应   总被引:12,自引:0,他引:12       下载免费PDF全文
摘要:伴随相对海平面由上升转为下降的周期变化,塔里木盆地在早古生代经历了一次大规模的扩张→挤压→隆升的开合旋回,早期(震旦纪—中奥陶世)处于拉张的构造背景下,呈现西台(碳酸盐台地)东盆(满加尔.库鲁克塔格深水盆地)的古地理格局。中西部广大地区沉积了巨厚的浅水台地相碳酸盐岩,以中晚寒武世的下丘里塔格群和早中奥陶世的上丘里塔格群为标志;东部的满加尔-库鲁克塔格则以厚度不大的远洋硅-灰泥沉积为主。盆地构造性质的转换及沉积古地理的巨大改变发生于中奥陶世中晚期,以塔中、塔北的隆起和塘古孜巴斯坳陷及阿瓦提-满加尔坳陷的形成为标志,呈近南北向隆-坳相问的盆地格局。沉积记录的响应表现为碳酸盐台地的消失、陆源物质的逐渐注入和向上变粗、火山活动和火山碎屑的出现以及巨厚砂泥质浊积岩在塔东盆地内的充填等。因此,中晚奥陶世—中泥盆世是塔里木盆地海域逐渐萎缩、盆地不断隆升和相对海平面逐渐下降的一个过程。  相似文献   

15.
不整合结构与不整合面结构具有不同的属性及特征.本文在分析不整合三层结构的基础上,进一步剖析了平行不整合、角度不整合、异岩不整合等3大类不整合的结构构造,划分出10个具有不同结构特征的不整合亚类.重点针对不整合面下的构造变形特征、不整合结构类型的平面分布、不整合面上的初始沉积物、物源及其层序结构等展开了精细研究,对不同结构类型的不整合形成运动学及动力学进行了初步探讨.并以塔里木盆地志留系与奥陶系不整合为例,在盆地尺度,解析不同区域不整合结构类型的特征、性质及差异.现今保留的志留系与奥陶系不整合在盆地中南部广大地区呈角度不整合,在阿瓦提-满加尔坳陷南部、巴楚隆起中西部、塔中隆起北部为低角度、北倾的单斜角度不整合;在塘古兹巴斯凹陷表现为中-低角度的断褶不整合,呈北东向展布,在巴楚隆起东部及塔中隆起的南部局部也存在北东向展布的断褶不整合.在盆地北部塔北隆起西部局部存在褶皱不整合,东部存在低角度、南倾、单斜不整合.而盆地中部在阿瓦提-满加尔凹陷中北部、塔东凹陷东北则以平行不整合为特征.结合沉积地层发育及构造演化分析,恢复了志留系沉积前构造古地理,塔里木盆地大部分为混积陆棚沉积、中部碳酸盐岩台地被逐渐淹没,满加尔及英吉苏凹陷为盆地相沉积.伴随着盆地南缘西昆仑-库地洋、南阿尔金洋的闭合及碰撞造山,在盆地南部主体为南北向的缩短,塘古兹巴斯凹陷为南东-北西向缩短,且变形强度明显大于南北向的缩短.因此,盆地南部的南东-北西向挤压作用是该期最活跃的构造作用,和田古隆起北部、塘古兹巴斯凹陷北东向加里东期褶皱带西北部,应是塔里木盆地第一期油气大规模运移聚集的有利区,值得进一步探索.本文通过对不同时期不整合结构的解剖,尝试区别分析不同期次构造事件的作用及效应,识别单一构造事件(或构造运动)在构造古地理重建及成藏、成矿中的作用.  相似文献   

16.
塔里木盆地塔中低凸起古构造演化与变形特征   总被引:14,自引:0,他引:14  
通过区域地质和构造地震精细研究,提出了塔里木南缘早古生代板块构造控制塔南—塔中从伸展到挤压盆地演化:寒武纪—早奥陶世板缘拉张控制了塔中北斜坡断陷构造;中奥陶世北昆仑洋盆关闭后塔中前缘隆起;晚奥陶世—晚泥盆世塔中前陆冲断与走滑构造变形。晚奥陶世塔南前陆冲断构造由东南向西北方向传播,形成塘北—塔中南—塔中5号断裂带等弧形断裂体系和塔中低凸起中西段与Ⅰ号断裂带小角度斜交的走滑断裂体系。冲断构造位移的传播受控于两个滑脱层:其一是沿寒武系内部膏盐岩的滑脱,形成弧形冲断构造,终止于塔中南缘断裂带;另一个是沿中地壳韧性变形带的滑脱,形成塔中1号断裂带东端的弧形构造带。塔中1号断裂带东段的构造变形方式主要为向北传播水平位移的断层传播褶皱和向南反向冲断的楔形构造。塔中低凸起的中西段右行走滑构造导致了向东收敛的扫帚状走滑断裂体系的形成,剖面发育花状构造。塔中低凸起的古构造演化与变形特征、构造变形样式、构造变形成因和断裂体系,是克拉通盆地内部叠合盆地深层的主要构造地质特征。  相似文献   

17.
The Tianshan range could have been built by both late Early Paleozoic accretion and Late Paleozoic collision events. The late Early Paleozoic Aqqikkudug-Weiya suture is marked by Ordovician ophiolitic melange and a Silurian flysch sequence, high-pressure metamorphic relics, and mylonitized rocks. The Central Tianshan belt could principally be an Ordovician volcanic arc; whereas the South Tianshan belt, a back-arc basin. Macro- and microstructures, along with unconformities, provide some kinematic and chronological constraints on 2-phase ductile deformation. The earlier ductile deformation occurring at ca. 400 Ma was marked by north-verging ductile shearing, yielding granulite-bearing ophiolitic melange blocks and garnet-pyroxene-facies ductile deformation, and the later deformation, a dextral strike-slip tectonic process, occurred during the Late Carboniferous-Early Permian. Early Carboniferous molasses were deposited unconformably on pre-Carboniferous metamorphic and ductilely sheared rocks, implying t  相似文献   

18.
塔里木盆地塔中隆起构造演化与油气关系   总被引:5,自引:0,他引:5       下载免费PDF全文
笔者结合塔里木盆地形成的构造背景对塔中隆起的主要构造演化过程进行了研究,并具体分析了各构造演化阶段与志留系油气的关系。研究表明,塔中隆起源于早古生代拉张背景下的正断层,寒武-奥陶纪为其烃源岩形成的重要时期;早奥陶世末-晚奥陶世末的构造反转是塔中隆起的主要形成期,同时也为志留系的形成及复合圈闭提供了古地理背景;泥盆纪末塔中鼻状隆起基本定型,古油藏遭受破坏,形成了沥青砂岩;早二叠世晚期的构造变形使古油藏遭受进一步的破坏;二叠纪后构造变动主要以调节为主。伴随整个构造的演化,志留系的油气聚集也是分期次、不同规模的进行。  相似文献   

19.
中国含油气盆地以叠合盆地为主,经历多期次构造运动,造成盆地内部多期古隆起的复合叠加;目前对于多期活动古隆起复合叠加过程的解析研究较为薄弱。本文以塔里木盆地轮南古隆起为例,利用最新的三维地震数据和钻井资料,应用构造解析和古构造复原的方法,明确轮南古隆起经历寒武纪-早中奥陶世前古隆起、晚奥陶世古隆起形成、晚泥盆-早石炭世叠加改造、晚二叠世-三叠纪古隆起定型、侏罗纪-古近纪古隆起埋藏和新近纪以来构造掀斜6个演化阶段;揭示现今以寒武-奥陶系碳酸盐岩为主体的前中生界隆起是由位于研究区西北侧北东向展布的晚奥陶世古隆起、研究区中部北北东向展布的晚泥盆-早石炭世古隆起和研究区北侧近东西向展布的晚二叠世-三叠纪古隆起三者复合叠加而成;不同时期古隆起成因机制有差异,但都与盆地周缘洋盆闭合、造山作用关系密切。  相似文献   

20.
塔里木盆地北部奥陶系油气相态及其成因分析   总被引:8,自引:3,他引:5  
塔里木盆地北部地区奥陶系是最重要的勘探层系,油气资源丰富;同时油气相态复杂多样,既有凝析气藏、正常油藏,也有稠油油藏、沥青等。通过对油气藏形成演化与保存过程的系统分析,结合油气地球化学和流体包裹体等分析数据,发现油气相态的多样性与油气多期次充注与次生蚀变作用有关。提出塔北隆起的东部奥陶系存在三期油气充注过程,分别发生在加里东运动晚期-海西早期、海西运动晚期、喜马拉雅运动晚期,原油主要来源于中、上奥陶统烃源岩,天然气主要来自与寒武系烃源岩有关的液态烃的裂解;塔北隆起的中西部奥陶系的油气充注主要发生在海西运动晚期。塔北奥陶系油藏形成以后,经历了三期明显的调整改造过程:海西早期构造抬升导致志留-泥盆系遭受剥蚀,东部源自寒武系油气的古油藏遭受破坏,形成沥青;三叠系沉积前的晚海西运动,使得奥陶系生源的油藏大范围遭受降解稠化;晚喜山期,来自于满加尔坳陷的天然气自东向西充注,致使隆起东部早期形成的油藏发生强烈的气侵改造,形成次生凝析气藏。而中西部奥陶系油藏在三叠系沉积前遭受降解稠化后,一直处于沉降深埋过程,油藏得到有效保存;由于成藏时间较早,轻质组分散失较多,气油比极低,油质较稠。研究认为,油气相态的多样性主要受晚海西期构造运动的抬升造成的生物降解作用和喜马拉雅晚期构造运动造成的天然气自东向西大规模充注对油藏进行气洗改造两大过程的控制。  相似文献   

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