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1.
持续沉降是墨西哥湾油气区优质烃源岩形成的重要条件   总被引:1,自引:0,他引:1  
墨西哥湾盆地是一个典型的中生代—新生代裂谷盆地,形成于北美克拉通南部边缘,大部分时间处于持续而稳定的沉降作用过程中。自晚侏罗世以来持续稳定的沉降形成了中生代富有机质的缺氧海相碳酸盐岩、黑色钙质页岩和泥质石灰岩等优质烃源岩,以及新生界以陆源碎屑为主的巨厚沉积物,存在大量的潜在烃源岩,加之良好的生储盖组合,从而形成了墨西哥湾盆地丰富的油气聚集。  相似文献   

2.
墨西哥及墨西哥湾盆地构造单元及其演化   总被引:2,自引:0,他引:2  
墨西哥及墨西哥湾盆地中生代以来可划分为两个一级构造单元,分别是墨西哥造山带和墨西哥湾盆地,进一步可划分二级构造单元6个,其中在墨西哥造山带划分了3个二级构造单元,分别是下加里福尼亚造山带、西马德雷—南马德雷岛弧带和东马德雷逆冲挤压带。在墨西哥湾盆地也划分了3个二级构造单元,分别是墨西哥湾盆地区、佛罗里达地块和尤卡坦地块。墨西哥造山带的形成是大洋板块和大陆板块相互作用的结果,但在不同构造单元上的表现不同。墨西哥湾盆地是一个中生代—新生代的裂谷盆地,包括内陆带、沿海带和洋壳带。根据墨西哥湾盆地构造地层幕将墨西哥湾盆地构造演化分为5个演化阶段,分别为晚三叠世到早侏罗世时期裂谷阶段,中侏罗世裂谷和地壳衰减阶段,晚侏罗世洋壳生成阶段,早白垩世下降阶段和晚白垩世至新生代陆源物质沉积和盐构造变形阶段。  相似文献   

3.
为了探讨北海盆地油气富集的控制因素,对前人在该区的大量研究成果进行了整理和分析,结果显示,北海盆地三叉裂谷所在的3个地堑具有上下2层不同的结构特征,即晚侏罗世末期的裂谷拉伸运动造就了北海盆地的下构造层,而早白垩世之后的热沉降作用塑造了北海盆地的上构造层;断层主要分布在下白垩统之下的老地层中。北海盆地油气成藏组合主要受下构造层的控制,成藏模式主要表现为中生代砂岩断—背斜油气藏,因此,可以认为,北海盆地油气富集的主要控制因素是晚侏罗世—早白垩世的裂谷拉伸运动。  相似文献   

4.
本文从南太平洋地区区域构造演化出发,开展盆地类型划分和石油地质条件分析,了解不同类型盆地的油气成藏特征,并分析油气分布规律和资源潜力,以期对未来油气勘探开发国际合作选区提供借鉴。研究表明:(1)南太平洋地区经历了亨特-鲍恩造山运动、澳大利亚板块与南极洲板块分离、塔斯曼海扩张及珊瑚海扩张、巴布亚新几内亚地区的洋壳俯冲和弧-陆碰撞作用,最终形成了澳大利亚东部南缘和海域及新西兰地区以裂谷盆地为主、澳大利亚东部内陆以克拉通盆地为主的包括晚二叠世-三叠纪前陆盆地、古近纪-新近纪前陆盆地、古近纪-现今弧前盆地和弧后盆地6种盆地类型;(2)澳大利亚内陆南缘和东部海域以及新西兰地区裂谷盆地分布广泛,裂谷盆地油气最为富集,但内陆和海域有所差异,内陆南缘裂谷盆地油气资源丰富且石油与天然气的比值约为2:1,而东部海域裂谷盆地因油气成藏条件差,尚无油气发现;(3)根据盆地的剩余可采储量和远景资源量对南太平洋地区的资源潜力进行分析,认为白垩纪-古近纪裂谷盆地和古近纪-新近纪前陆盆地油气资源潜力最大,并优选出吉普斯兰(Gippsland)、塔拉纳基(Taranaki)和巴布亚(Papua)3个有利盆地。  相似文献   

5.
位于巴西东岸的南大西洋被动大陆边缘盆地-桑托斯盆地是我国海外油气勘探的重要区块。通过地震资料分析,结合叠合盆地演化原理以及南大西洋演化历程,将桑托斯盆地的构造演化阶段划分为前裂谷期、裂谷期、过渡期、漂移期4个阶段,对应克拉通、裂谷、坳陷、被动大陆边缘4类原型盆地。原型盆地的时空匹配关系为桑托斯盆地形成超大型的含油气系统提供了极为理想的构造条件。结合前人的研究成果对盆地"生储盖"组合分析,得出桑托斯油气富集成藏的规律,即"厚盐区盐下富集;薄盐区盐上富集"。通过对盆地区域构造史以及所得的地震资料分析,认为在目前重视不足的盐下东部坳陷地区存在厚层优质的湖相烃源岩,烃类沿着基底大断裂以及不整合面运移,被过渡期蒸发盐岩所阻挡,形成以构造-地层复合圈闭和地层不整合遮挡圈闭为主的油气藏。  相似文献   

6.
以区域地质、地震等资料为基础,系统研究了台西盆地乌丘屿凹陷构造特征及其形成演化。台西盆地的发育受欧亚板块、印度板块、太平洋板块和菲律宾海板块4大板块共同作用的影响。中生代晚期,台西盆地区域应力场从挤压转为松弛,地壳拉张减薄。新生代初期拉张形成裂谷,乌丘屿凹陷是在此背景下发育而成东断西超的半地堑式陆缘断陷。乌丘屿凹陷的构造发育与演化过程,可分为4个阶段,分别为中生代晚期的裂前阶段、古新世至渐新世的断陷阶段、中新世的坳陷阶段和上新世至第四纪的区域沉降阶段。  相似文献   

7.
南海北部中生代沉积模式   总被引:6,自引:2,他引:4  
南海东北部与西北部海域均分布有中生代地层,地震勘探揭示南海北部中生界东、西之间在地震相及沉积充填结构上存在明显差异,东部中生界为双层结构,而西部为单层结构.东部中生代地层由海相及海陆过渡相侏罗系与陆相白垩系组成,而西部则由陆相白垩系构成,缺失侏罗系.从海水入侵方向看,南海北部中生界与特提斯域无关,可能更受太平洋域的影响.侏罗纪古太平洋边缘海盆在南海北部主要分布在珠江口盆地东部及台西南盆地,从早侏罗世到晚侏罗世海盆范围逐渐缩小;白垩纪南海北部整体抬升,除台西南盆地东部接受海相沉积外,白垩纪南海北部以小型断陷盆地为特征,在断陷盆地内接受陆相河湖相沉积.南海北部在中生代时期位于特提斯构造域与太平洋构造域的交接部位,东部中生界双层结构、西部单层结构的沉积模式进一步明确濒太平洋构造域的对南海北部中生界的控制作用,同时东部将是中生代油气勘探的有利区域.  相似文献   

8.
一系列的钻探和拖网取样都表明南沙群岛海区东、南部存在中生代海相沉积.新的国家重点基础研究发展计划地震测线经过南沙群岛海区北部,调查采用了长排列、高分辩率技术.所获地震剖面显示在披覆沉积和裂谷式充填沉积之下,还存在大套具有密集反射、倾斜形变和高角度断裂的下构造层.结合南海的构造演化过程以及钻探和拖网取样结果对比,将上覆构造层划为裂谷期及裂谷后期沉积,下构造层划为中生代沉积.残留的厚层海相中生界呈北东―西南向条带状相间分布,反映新生代拉张具有明显的块断特点.根据中生界的地层和变形特点,进一步推断南沙群岛海区北部位于中生代东亚陆缘弧前盆地的近弧一侧.  相似文献   

9.
在对南黄海盆地海相中、古生界烃源条件和后期保存条件研究的基础上,运用盆地模拟手段并结合前人研究成果,对海相地层烃源岩的排烃史进行了模拟,计算了海相地层油气资源量,从而进行了海相油气资源潜力的分析;同时通过对海相上构造层和下构造层两套含油气系统成藏条件的研究,预测了盆地内海相油气资源的有利运聚区,进而指出南黄海盆地海相油气勘探的有利区,为下一步南黄海盆地的勘探部署提供了依据。研究表明,南黄海盆地海相下构造层和海相上构造层栖霞组、龙潭组—大隆组烃源岩推测为好的烃源岩,海相上构造层青龙组烃源岩推测为中等—好的烃源岩;盆地海相地层具有一定的油气资源潜力,油气资源总量为35.37×10^8t,且在纵向上,油气资源主要来自海相下构造层烃源岩系,在平面上主要分布于南部坳陷;盆地海相地层存在两类油气资源勘探有利区,其中,最有利区位于中部隆起区南部、南部坳陷区和勿南沙隆起区北部。  相似文献   

10.
中国近海盆地处在欧亚、印度-澳大利亚及太平洋三大板块相互作用之新生代最活跃区域,古近纪以来,经历了多期构造活动,尤其是中新世以来的新构造运动较强烈,在此区域地质背景的影响和制约下,中国近海盆地构造演化具有幕式演化特征,逐渐形成了"沟-弧-盆"系统,在边缘海浅水及深水区形成了一系列具有断坳双层结构的不同类型的新生代盆地,沉积充填了古近纪断陷裂谷早期中深湖相地层及其烃源岩、断陷晚期煤系地层及烃源岩、新近纪坳陷期中新统海相地层及其烃源岩,进而为油气形成奠定了雄厚的物质基础。中国近海盆地沉降沉积中心具有由陆逐渐向深海洋盆迁移的特点,形成了多套不同类型储盖组合,加之与晚期新构造运动和烃源供给系统时空上相互耦合配置,进而最终形成并控制影响了近海沉积盆地油气分布富集规律。  相似文献   

11.
南海北缘新生代盆地沉积与构造演化及地球动力学背景   总被引:32,自引:0,他引:32  
南海北缘新生代沉积盆地是全面揭示南海北缘形成演化及与邻区大地构造单元相互作用的重要窗口。通过对盆地沉积-构造特征分析,南海北缘新生代裂陷过程显示出明显的多幕性和旋转性的特点。在从北向南逐渐迁移的趋势下,东、西段裂陷过程也具有一定的差异,西部裂陷活动及海侵时间明显早于东部,裂陷中心由西向东呈雁列式扩展。晚白垩世-早始新世裂陷活动应是东亚陆缘中生代构造-岩浆演化的延续,始新世中、晚期太平洋板块俯冲方向改变导致裂陷中心南移,印度欧亚板块碰撞效应是南海中央海盆扩张方向顺时针旋转的主要原因。  相似文献   

12.
郯庐断裂带自南而北穿越渤海东部,自中生代中期至新生代中期表现裂谷发育特征。裂谷发育经历两个旋回,各旋回的裂谷发育演化、盆地分布格局,沉积相带,沉积补偿速度等均受断裂带的断裂活动的强烈控制。  相似文献   

13.
The South Caspian Basin (SCB) is a relic of the back-arc basin in the margin of the Tethys paleoocean. The SCB has an oceanic-type crust and is filled with a thick (15–28 km) sedimentary series. In the modern structure, it is a part of the South Caspian microplate, which also comprises the Lower Kura and West Turkmenian depressions, parts of the Kopet Dagh and Alborz ranges. The geological and seismological data evidence an underthrust (or, probably, subduction) of the South Caspian Basin’s lithosphere beneath the Apsheron threshold and the simultaneous westward displacement of the South Caspian Microplate (SCM). Different authors refer the South Caspian Basin’s formation to the Early Mesozoic, Late Jurassic, and Paleocene. In this paper, on the basis of geologic information, a two-phase model of the South Caspian Basin’s opening is considered. The first phase is referred to the Late Triassic-Early Jurassic, when the sinking of the Kopet Dagh Basin and the opening of the Great Caucasus rift began as well. Jointly, these three structures formed a prolonged basin related to the development of the Early Mesozoic subduction zone. The age of the oceanic crust in the central part of the South Caspian Basin calculated by the thermal flux is 200 Ma. The second phase of the South Caspian Basin opening referred to the Eocene is related to the extension in the back-arc part of the Elbrus volcanic arc. The formation of the oceanic crust in the southwestern part of the South Caspian Basin and in the Lower-Kura depression is associated with this phase, which is proved by the high values of the thermal flux.  相似文献   

14.
The prolific, oil-bearing basins of eastern Venezuela developed through an unusual confluence of Atlantic, Caribbean and Pacific plate tectonic events. Mesozoic rifting and passive margin development created ideal conditions for the deposition of world-class hydrocarbon source rocks. In the Cenozoic, transpressive, west-to-east movement of the Caribbean plate along the northern margin of Venezuela led to the maturation of those source rocks in several extended pulses, directly attributable to regional tectonic events. The combination of these elements with well-developed structural and stratigraphic fairways resulted in remarkably efficient migration of large volumes of oil and gas, which accumulated along the flanks of thick sedimentary depocenters.At least four proven and potential hydrocarbon source rocks contribute to oil and gas accumulations. Cretaceous oil-prone, marine source rocks, and Miocene oil- and gas-prone, paralic source rocks are well documented. We used reservoired oils, seeps, organic-rich rocks, and fluid inclusions to identify probable Jurassic hypersaline-lacustrine, and Albian carbonate source rocks. Hydrocarbon maturation began during the Early Miocene in the present-day Serrania del Interior, as the Caribbean plate moved eastward relative to South America. Large volumes of hydrocarbons expelled during this period were lost due to lack of effective traps and seals. By the Middle Miocene, however, when source rocks from the more recent foredeeps began to mature, reservoir, migration pathways, and topseal were in place. Rapid, tectonically driven burial created the opportunity for unusually efficient migration and trapping of these later-expelled hydrocarbons. The generally eastward migration of broad depocenters across Venezuela was supplemented by local, tectonically induced subsidence. These subsidence patterns and later migration resulted in the mixing of hydrocarbons from different source rocks, and in a complex map pattern of variable oil quality that was further modified by biodegradation, late gas migration, water washing, and subsequent burial.The integration of plate tectonic reconstructions with the history of source rock deposition and maturation provides significant insights into the genesis, evolution, alteration, and demise of Eastern Venezuela hydrocarbon systems. We used this analysis to identify additional play potential associated with probable Jurassic and Albian hydrocarbon source rocks, often overlooked in discussions of Venezuela. The results suggest that oils associated with likely Jurassic source rocks originated in restricted, rift-controlled depressions lying at high angles to the eventual margins of the South Atlantic, and that Albian oils are likely related to carbonate deposition along these margins, post-continental break up. In terms of tectonic history, the inferred Mesozoic rift system is the eastern continuation of the Espino Graben, whose remnant structures underlie both the Serrania del Interior and the Gulf of Paria, where thick evaporite sections have been penetrated. The pattern of basin structure and associated Mesozoic deposition as depicted in the model has important implications for the Mesozoic paleogeography of northern South America and Africa, Cuba and the Yucatan and associated new play potential.  相似文献   

15.
太阳盆地中新生代断裂特征及成因机制   总被引:1,自引:0,他引:1  
太阳盆地位于北黄海盆地的东部,是一个发育在中-朝克拉通基底之上的中、新生代沉积盆地,勘探程度非常低。最新二维地震资料揭示,太阳盆地的断裂体系可以分控盆断裂、控凹(坳)断裂、控带断裂、控圈断裂和分割性断裂。盆地发育以NE向和NW向为主的的正断层和逆断层,而少量断层呈近EW或SN向。对不同类型的断裂构造特征及样式分析表明,断裂的活动期次可分为4期:晚侏罗世—早白垩世伸展断层、晚白垩世逆冲断层、始新世伸展正断层和新近纪正断层。中、新生代以来,中国东部构造演化主要受其东部太平洋板块活动控制,晚侏罗纪开始,洋壳俯冲在东部的欧亚大陆之下,伴随着太平洋—菲律宾板块的俯冲,太阳盆地发生NNE—SSW向的拉张;晚白垩世时期,由于太平洋板块俯冲方向的改变,区域性拉张变为区域性NNW—SSE向挤压,太阳盆地的一系列NW向逆断层形成;在始新世—渐新世,太平洋板块向东亚大陆作斜向减速俯冲,导致太阳盆地遭受NWW—SEE向拉张作用,再次断陷;渐新世末期,受喜山运动第Ⅱ幕的影响,太阳盆地发生再次的构造反转,形成一系列的小规模断层。  相似文献   

16.
The continental margin of Western Australia is a rifted or “Atlantic”-type margin, with a complex physiography. The margin comprises a shelf, an upper and lower continental slope, marginal plateaus, a continental rise, and rise or lower slope foothills. Notches or terraces on the shelf reflect pre-Holocene deposition of prograded sediment, whose seaward limit was determined by variations in relative sea level, wave energy, and sediment size and volume. The upper continental slope has four physiographic forms: convex, due to sediment outbuilding (progradation) over a subsiding marginal plateau; scarped, due to erosion of convex slopes; stepped, due to deposition at the base of a scarped slope; and smooth, due to progradation of an upper slope in the absence of a marginal plateau. Lying at the same level as the upper/lower slope boundary are two extensive marginal plateaus: Exmouth and Scott. They represent continental crust which subsided after continental rupture by sea-floor spreading. Differential subsidence, probably along faults, gave rise to the various physiographic features of the plateaus. The deep lower continental slope is broken into straight northeasterly-trending segments, that parallel the Upper Jurassic/Lower Cretaceous rift axis, and northwesterly-trending segments that parallel the transform direction. The trends of the slope foothills are subparallel to the rift direction. The four abyssal plains of the region (Perth, Cuvier, Gascoyne and Argo) indicate a long history of subsidence and sedimentation on Upper Jurassic/Lower Cretaceous oceanic crust.  相似文献   

17.
Various settings took place during the Late Mesozoic: divergent, convergent, collisional, and transform. After mid-Jurassic collision of the Siberian and Chinese cratons, a latitudinal system of post-collision troughs developed along the Mongol-Okhotsk suture (the Uda, Torom basins and others), filled with terrigenous coal-bearing molasse.The dispersion of Pangea, creation of oceans during the Late Jurassic are correlated to the emergence of the East Asian submeridional rift system with volcano-terrigenous coal-bearing deposits (the Amur-Zeya basin). At that time, to the east there existed an Andean-type continental margin. Foreland (Upper Bureya, Partizansk, and Razdolny) and flexural (Sangjiang-Middle Amur) basins were formed along the margin of the rigid massifs during the Late Jurassic to Berriasian.During the Valanginian-mid-Albian an oblique subduction of the Izanagi plate beneath the Asian continent occurred, producing a transform margin type, considerable sinistral strike slip displacements, and formation of pull-apart basins filled with turbidites (the Sangjiang-Middle Amur basin).The Aptian is characterized by plate reorganization and formation of epioceanic island arcs, fore-arc and back-arc basins in Sakhalin and the Sikhote-Alin (the Alchan and Sangjiang-Middle Amur basins), filled with volcanoclastics.During the mid-Albian a series of terranes accreted to the Asian continental margin. By the end of the Albian, the East Asian marginal volcanic belt began to form due to the subduction of the Kula plate beneath the Asian continent. During the Cenomanian–Coniacian shallow marine coarse clastics accumulated in the fore-arc basins, which were followed by continental deposits in the Santonian–Campanian. From the Coniacian to the Maastrichtian, a thermal subsidence started in rift basins, and continental oil-bearing clastics accumulated (the Amur-Zeya basin).Widespread elevation and denudation were dominant during the Maastrichtian. This is evidenced by thick sediments accumulated in the Western Sakhalin fore-arc basin.During the Cenozoic, an extensive rift belt rmade up of a system of grabens, which were filled with lacustrine–alluvial coal–and oil-bearing deposits, developed along the East Asian margin.  相似文献   

18.
南沙海区中生界岩相分布及构造特征   总被引:3,自引:0,他引:3       下载免费PDF全文
为了了解南中国海南部南沙群岛陆架-陆坡区中生代地层发育情况,作者通过综合分析该海区钻井、拖网及1987年以来采集的20000多公里的多道反射地震勘探等资料,得到了对该区中生界基本特征的如下新认识:空间分布上,南沙的中生界具有从北部的郑和-礼乐隆起南缘向南增厚的趋势;沉积岩相方面,东部三叠纪时为深海相,侏罗纪为浅海与三角洲相,白垩纪为浅海-内浅海相,而往西南部中生代的海水深度有变深的趋势;中-新生代变形上,在南沙西部的曾母盆地,中生界褶皱为复式的、非协调性的,南沙中部多为舒缓褶皱,东部仅在近巴拉望海槽地带出现小幅度的褶皱。结合围区中生界及特提斯构造域的发育特征,作者提出南沙地块上的海相中生界在大地构造上归属于残留在中特提斯洋北部减薄陆缘地壳上的中特提斯期海相沉积地层,是该海域油气资源勘探不可忽视的对象。  相似文献   

19.
东海陆架盆地是位于中国东部华南大陆边缘的一个中、新生代叠合盆地,具有较大油气潜力。目前东海陆架盆地油气的发现均来自于新生界,对中生代残留地层的各方面特征认识不足:在空间上通常集中于特定构造单元,且基本位于盆地西部;在时间上主要涉及白垩纪和侏罗纪,且多是定性或半定量的研究。本文在前人研究的基础上,收集、整理了研究区目前最新、最全的反射地震资料和钻井数据,从钻遇中生界井的标定出发,以地震资料的层序划分和解释为基础,进行残留地层的研究,空间上统一盆地东、西两大坳陷带,时间上统揽白垩纪、侏罗纪以及前侏罗纪三个时期。结果表明,东海陆架盆地中生代残留地层遭受了后期严重的剥蚀改造,总体呈现东厚西薄、南厚北薄的特征,残留地层范围随时间不断东扩。对比各时期残留地层平面展布特征,揭示了东海陆架盆地的演变过程:三叠纪时期盆地原型为被动大陆边缘坳陷型盆地,早、中侏罗世时期为活动大陆边缘弧前盆地,晚侏罗世—晚白垩世时期为大陆边缘弧后伸展盆地;与此相对应,古太平洋板块俯冲肇始于晚三叠世—早、中侏罗世时期,板块后撤始于晚侏罗世。东海陆架盆地在中生代的东侧边界位于钓鱼岛隆褶带的东侧。  相似文献   

20.
东海陆架盆地南部中生代构造演化与原型盆地性质   总被引:10,自引:0,他引:10  
东海陆架盆地南部夹持于欧亚板块、太平洋板块与印度板块之间,是发育在前中生代基础之上的中、新生代叠合盆地。其构造演化受古太平洋板块俯冲及特提斯-喜马拉雅构造域的联合影响,经历了印支末期基隆运动、燕山期渔山和雁荡运动的叠加改造。结合浙闽隆起带中生代火成岩事件、盆地构造变形、沉积学的一些证据,通过海陆对比研究,认为东海陆架盆地南部早-中三叠世可能为面向古太平洋的被动大陆边缘盆地;晚三叠世-侏罗纪古太平洋板块已对中国大陆有较强的俯冲作用,东海陆架盆地及南部原型盆地为活动大陆边缘弧前盆地;白垩纪受控于滨海断裂表现为活动大陆边缘走滑拉分盆地;古新世-始新世火山岛弧向东移动,东海陆架变为弧后裂谷盆地。  相似文献   

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