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西非被动大陆边缘重力滑脱构造体系下的塑性构造 总被引：3，自引：0，他引：3
论述了西非被动大陆边缘深水环境下的重力滑脱构造体系中的塑性构造。研究发现塑性地层在整个西非被动大陆边缘都有分布,且盐岩塑性层主要分布在西非被动大陆边缘的西南部和西北部,发育层位为过渡期(J-K)构造层之内;中部尼日尔三角洲等塑性层主要为泥岩塑性层,发育层位为古近系和新近系。根据重力滑脱构造体系发育特征可划分为:以正断裂和塑性焊接构造为主的上部重力滑脱伸展构造、以底辟构造为主的中部重力滑脱底辟构造、以冲断裂、塑性褶皱和塑性冲断构造为主的下部重力滑脱冲断构造。根据塑性构造上覆地层的变形过程,塑性构造演化主要经历了后生变形期和同生变形期。塑性构造变形机制主要受基底掀斜作用和上覆地层的沉积速率控制。塑性构造中的底辟、褶皱、冲断及塑性焊接构造对油气成藏的控制作用依次减弱。 相似文献
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白博康洪全程涛贾怀存王健 《海洋地质前沿》2016,(4):31-36
重力滑脱构造是被动大陆边缘盆地广泛发育的一种构造样式。从重力滑脱构造的形成机制出发,分析并指出巴西东北部海域盆地重力滑脱构造主要分布区域有:福斯杜—亚马逊、帕拉—马拉尼郝和巴雷里尼亚斯盆地深水区;进而对这3个盆地的重力滑脱构造特征进行分析,明确了重力滑脱伸展区、平移区、冲断区的构造样式及圈闭发育类型。其中,福斯杜—亚马逊盆地重力滑脱构造最为发育且圈闭类型多样,受漂移晚期重力滑脱作用影响形成的伸展和冲断构造是盆地的主要圈闭类型。最后,论述了福斯杜—亚马逊盆地重力滑脱构造对油气的控制作用及其勘探潜力。 相似文献
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《海洋地质与第四纪地质》2016,(2)
扎格罗斯前陆盆地是由于阿拉伯板块和欧亚板块发生陆陆碰撞而形成的周缘前陆盆地。自造山带向西南方向推进可分为叠瓦冲断带、强烈褶皱带、宽缓褶皱带和前渊凹陷带4个构造单元。扎格罗斯型周缘前陆盆地具有与常规前陆盆地模式不同的构造样式,该区域前隆带和隆外凹陷不发育,褶皱变形区则分为叠瓦冲断带、强烈褶皱带和宽缓褶皱带3个部分。叠瓦冲断带和强烈褶皱带构造变形破坏强烈,不利于圈闭油气后期聚集和保存,因此较少发现油气;而宽缓褶皱带和前渊凹陷带褶皱变形较为舒缓,该区域油气富集。可见,扎格罗斯前陆盆地不同构造单元中不同的构造样式对应各异的圈闭类型。扎格罗斯前陆盆地的形成受控于陆陆碰撞引起的挤压应力,其不同单元间构造形态各异,褶皱形态等受走滑断层和滑脱地层的影响。通过对扎格罗斯前陆盆地的构造样式进行分析,对比了传统前陆盆地和扎格罗斯前陆盆地的异同,较系统地总结了扎格罗斯前陆盆地的圈闭类型和成藏模式。 相似文献
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西非被动大陆边缘盐构造样式与成因机制 总被引：1，自引：0，他引：1
基于三维地震资料,对西非陆缘盐构造样式及分布特征进行了刻画,剖析了其形成演化机制与控制因素。西非陆缘盐上地层滑脱形成典型的薄皮构造,前缘发育挤压变形,后缘发育拉张变形,两者之间为过渡变形。拉张区发育白垩系盐筏、前盐筏、新近系盐筏等盐构造;过渡变形区以发育各种底辟构造为特征;挤压变形区主要发育侵位盐席构造。重力滑脱作用是被动陆缘盐构造发育过程中始终存在的驱动机制,重力扩展作用在大陆边缘成熟阶段作用明显,在陆缘演化早期并不突出。陆缘构造活动控制盐构造的形成,差异沉积负载作用影响着盐上地层滑移特征,而盐下底形对盐岩流动、盐上地层滑移速率及相关断裂体系的产生与沉积响应具有重要影响。 相似文献
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我们使用临界楔形体力学理论揭示了深水尼日尔三角洲中位于脆弱的基底滑脱面之上的趾状逆冲断裂系统由高孔隙压力所引起的变形。尼日尔三角洲中的沉积岩具有相似的岩石性质，但其锥度（海底斜坡和基底滑脱面的倾角之和）却比大多数造山褶皱带的要小得多。这种低锥度表明，尼日尔三角洲具有一个非常脆弱的基底滑脱面——一套含有基底滑脱面的前三角洲海相页岩，我们解释认为，这种脆弱的基底滑脱面反映了Akata组内上升的孔隙流体压力（λ≈0．90）。该脆弱基底滑脱带对深水尼日尔三角洲中的褶皱带具有很大的影响作用。超压的脆弱Akata组页岩在背斜核部和趾状褶皱与逆冲断裂构造的上盘中发生塑性变形，并导致切变断弯褶皱和滑脱背斜的形成，这些切变断弯褶皱和滑脱背斜正是深水尼日尔三角洲褶皱带中的主要圈闭类型。此外，低锥度还导致了背冲断裂带的广泛发育，以及位于深水褶皱和断裂带之间的大型的、变形相对轻微的地区的形成。在证明上升的基底流体压力对深水尼日尔三角洲的结构和构造的影响的同时，本项研究还将临界锥形楔力学概念的应用领域扩展到被动边缘背景中。 相似文献
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在深入调研南海深水盆地油气地质条件的基础上,系统分析了油气分布规律和成藏主控因素,明确了油气资源潜力和有利勘探方向,旨在为南海深水油气勘探决策提供科学依据。研究结果表明:南海深水盆地发育在非典型边缘海大陆边缘,其石油地质条件具有特殊性,油气分布特征存在显著的南北差异。其中,南海北部深水的珠江口盆地和琼东南盆地,以构造圈闭型油气藏为主;南海中南部深水的曾母盆地南部和文莱-沙巴盆地,主要为构造圈闭型油气藏,曾母盆地北部以岩性油气藏(生物礁滩型油气藏)为主,万安盆地主要为构造圈闭型和基岩潜山型油气藏。南海北部深水盆地和中南部深水盆地的烃源岩、储盖和圈闭等油气地质特征表明,南海深水盆地具有巨大的油气勘探潜力。南海深水的有利勘探方向为:①琼东南盆地乐东-陵水凹陷的中央峡谷、陵南斜坡带,松南-宝岛凹陷的反转构造带,宝岛凹陷北坡海底扇,长昌凹陷的环A洼圈闭带(海底扇);珠江口盆地白云凹陷的主洼深水扇、主洼两翼、西南断阶带,荔湾凹陷的深水扇。②南海中南部深水盆地的文莱-沙巴、曾母和万安盆地。 相似文献
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在西北婆罗州深水区，一个活动的海上褶皱冲断带内拥有大量已经证实的烃类聚集，相信继续的勘探活动还会发现相当可观的油气。在新近纪大规模褶皱冲断带中发现典型的圈闭几何形态是上盘背斜、前陆褶皱及隆起和逆断层下盘错动断开处。商业性钻井目标位于变形的中新统和上新统沉积地层中，其中充满的油气来自现今仍然活跃的含油气系统。此处主要面临的问题是避免钻探活动变形和近期隆起期间烃类已经排出的圈闭。构造变形阶段研究列出了控制圈闭形成史和烃类保存史的一些关键要素。本文目的是提供一个有关西北婆罗州深水区褶皱冲断带的总体看法，为今后这一地区的油气勘探介绍一些重要结果。 相似文献
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东非海岸主要含油气盆地属典型大陆裂谷层序和被动陆缘层序叠合的断坳型盆地,是在冈瓦纳大陆裂解及印度洋扩张的区域构造演化背景下形成的,均经历了卡鲁裂谷期、马达加斯加漂移期和被动大陆边缘期三期构造演化。但是,南、北盆地在构造及沉积演化特征及石油地质条件、油气分布上存在较大差异,北部盆地早期受特提斯洋海侵影响,沉积发育了侏罗系潟湖相盐岩、浅海相泥页岩,而南部盆地处于强烈火山作用区,二者油气富集规律存在差异,烃源岩、储盖组合由北向南年代逐渐变新,目前北部油气发现明显更为丰富。初步分析认为,构造环境不同使得烃源岩发育北富南贫,断裂及塑性岩体作用形成的通源断层和有利圈闭存在差异,导致了东非大陆边缘南、北部盆地油气成藏上的不同。 相似文献
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琼东南盆地华光凹陷构造特征及沉积充填 总被引：4，自引：0，他引：4
南海北部大陆边缘发育多个新生代含油气盆地。近年来,在南海北部珠江口盆地南部深水区陆续发现大中型气藏,证实了该区油气地质条件优越。琼东南盆地南部深水区与珠江口盆地深水区具有相似的构造沉积演化史,油气地质条件相似,具有形成大中型油气藏的地质条件,因此十分有必要开展该区的构造特征及沉积充填研究。基于近年来新采集的高精度地震资料,对华光凹陷构造特征进行详细分析,认为区内发育4种伸展构造样式,分别是地堑、半地堑、多米诺式半地堑和地垒;经历两个构造演化阶段,形成"下断上拗"的双层结构特征,相应发育两个期次的正断层。下构造层古近系受裂陷作用控制,断层发育,地层分布受断裂控制明显,上构造层新近系-第四系构造活动微弱,断层不发育,地层变形小且沉积厚度趋于稳定。华光凹陷古近系为河湖相-海陆过渡相沉积,其中下渐新统崖城组煤系地层是琼东南盆地勘探证实的主要烃源岩层系,上渐新统陵水组是主要储层发育时期,新近系-第四系为浅海-半深海-深海相沉积,其中中新统储层发育,上中新统及以上海相泥岩是良好的盖层。因此,华光凹陷具有良好的生储盖组合。 相似文献
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Fold-thrust belts formed above a ductile detachment typically contain detachment folds, whereas those formed above frictional detachments contain fault-related fold complexes, such as imbricate thrust systems. Analog models, using silica sand to represent sediments and silicone gel to represent salt were conducted to study the fold geometry, fold-fault relations, and sequential development of structures formed in each setting and at the boundaries between the two settings. The results showed a relatively thinner wedge above a ductile detachment, so that the deformation front propagated farther forward than that above a frictional detachment. The thrust front connects across the two settings with a significant change in position and a resulting change in orientation. The geometry of the deformation front is strongly controlled by that of the detachment boundary, so that an oblique detachment boundary results in an oblique thrust front in the transition zone. Modifications in the taper geometry also result from the presence of a frictional belt behind a ductile belt, the width of the ductile detachment which limits the location of the deformation front, and the lateral propagation of thrust faults between the two regimes. The experimental models can be used to explain observed geometries in natural examples of fold-thrust belts marked by transitions between frictional and ductile detachments. 相似文献
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世界主要深水含油气盆地储层特征 总被引：3，自引：0，他引：3
世界深水盆地油气资源丰富,良好的储层是形成较大油气藏的必要条件.以大量调研资料为基础,对大西洋区域的墨西哥湾、巴西东部边缘、非洲西海岸、挪威中部陆架及新特提斯区域的澳大利亚西北陆架、中国南海、孟加拉湾、地中海(尼罗河三角洲)8个地区的24个深水含油气盆地储层特征进行了综合分析,归纳总结了这些深水含油气盆地中主力储层的形... 相似文献
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Deep water fold and thrust belts (DWFTBs) are sedimentary wedges that accommodate plate-scale deformation on both active and passive continental margins. Internally, these wedges consist of individual structures that strongly influence sediment dispersal, bathymetry and fluid migration. Most DWFTB studies investigate basin- and intra-wedge- scale processes using seismic reflection profiles, yet are inherently limited by seismic resolution. Of critical importance is strain distribution and its accommodation on discrete faults compared to distributed deformation. Recent studies have considered strain distribution by investigating regional reflection DWFTBs profiles within coupled systems, which contain down-dip compression and up-dip extension. There is broad agreement of a mis-balance in compression versus extension, with ∼5% excess in the latter associated with horizontal compaction, yet this remains unproven.Using two exceptionally well exposed outcrops in the Spanish Pyrenees we consider deformation of DWFTB at a scale comparable to, and beyond, seismic resolution for the first time. By coupling outcrop observations (decametre to hectometre scale) with a re-evaluation of seismic profiles from the Orange Basin, South Africa, which contains one of the best imaged DWFTBs globally, we provide a unique insight into the deformation from metre to margin scale. Our observations reveal hitherto unrecognised second order structures that account for the majority of the previously recognised missing strain. This re-evaluation implies that ∼5% missing strain should be accounted for in all DWFTBs, therefore existing studies using restorations of the sediment wedge will have underestimated crustal shortening in active margins, or sedimentary shortening in gravity driven systems by this amount. In contrast to previous studies, our observations imply that the majority of this strain is accommodated on discrete fault surfaces and this can explain the occurrence and location of a range of intra-wedge processes that are intimately linked to structures including sediment dispersal, fluid migration pathways and reservoir compartmentalisation. 相似文献
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Shiuh-Tsann Huang Kenn-Ming Yang Jih-Hao Hung Jong-Chang Wu Hsin-Hsiu Ting Wen-Wei Mei Shiang-Horng Hsu Min Lee 《Marine Geophysical Researches》2004,25(1-2):139-156
The geological setting south of the Tsengwen River and the Tsochen Fault is the transitional zone between the Tainan foreland basin and Manila accretionary wedge in Southwestern Taiwan. This transitional zone is characterized by the triangle zone geological model associated with back thrusts that is quite unique compared to the other parts of the Western foreland that are dominated by thrust imbrications. The Hsinhua structure, the Tainan anticline, and the offshore H2 anticline are the first group of major culminations in the westernmost part of the Fold-and-Thrust belt that formed during the Penglay Orogeny. Structures in the the Tainan and Kaohsiung areas provide important features of the initial mountain building stage in Western Taiwan. A deeply buried basal detachment with ramp-flat geometry existed in the constructed geological sections. A typical triangle is found by back thrusting, such as where the Hsinhua Fault cuts upsection of the Upper Pliocene and Pleistocene from a lower detachment along the lower Gutingkeng Formation. The Tainan structure is a southward extension of the Hinhua Fault and has an asymmetric geometry of gentle western and steep eastern limbs. Our studies suggest that the Tainan anticline is similar to the structure formed by the Hsinhua Fault. Both are characterized by back thrusts and rooted into a detachment about 5 km deep. The triangle zone structure stops at H2 anticline offshore Tainan and beyond the west of it, All the structures are replaced by rift tectonic settings developed in the passive continental margin. On the basal detachment, a major ramp interpreted as a tectonic discontinuity was found in this study. Above the northeastern end of the major ramp of basal detachment, the Lungchuan Fault is associated with a triangle system development, while at the southwestern end a thrust wedge is present. It could be deduced that a thrust wedge intrudes northwestward. The area below the major ramp, or equivalent to the trailing edge of the basal detachment, mud diapers often occur in relation to the thickest deposits of the Gutingkeng Formation and caused by the mechanism of detachment folding 相似文献
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国内外深水区油气勘探新进展 总被引：15，自引：0，他引：15
深水区油气资源丰富，近年来深水油气勘探不断升温。在全球6大洲18个深水盆地中已发现约580亿桶油当量的油气资源。目前，巴西、美国墨西哥湾的深水油气田已经投入生产，而且产量不断增加，西非地区也已进入开发阶段，西北欧、地中海以及亚太地区的许多国家也都在积极开展深水油气勘探或开发。海上油气钻探不断向深水区和超深水区发展，探井数目也在继续增加，投资力度不断加强，储量每年也有很大的增长。深水油气勘探成功率平均达到30％，其中，西非的勘探成功率最高。深水区烃源岩生烃潜力较好，最好的烃源岩主要分布于侏罗系、白垩系和第三系的地层中，储层以浊积岩储层为主，盖层通常比较发育，大多数圈闭都与地层因素有关。我国南海北部陆坡深水区盆地属准被动边缘盆地，从烃源岩、储层、盖层、圈闭到运聚条件等都具备了形成大型油气田的基本地质条件，具有丰富的资源前景。 相似文献
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《Marine and Petroleum Geology》2003,20(6-8):547-561
Comparative bathymetric analyses of four siliciclastic continental margins reveal important distinguishing characteristics in deepwater receiving basin configurations. These characteristics have potential impact on deepwater sedimentation patterns and associated fan development. Present-day bathymetry was analysed quantitatively, using advanced software and digital bathymetry data. Various physical attributes of dip, basin geometry, and accommodation were quantified and mapped in 3D. Results show significant differences in receiving basin configurations between salt-based and shale-based continental margins in the Gulf of Mexico, Angola, Nigeria, and NW Borneo, especially in the type, amount, and distribution of accommodation. Salt-based systems have more ponded accommodation than shale-based systems; however, all the margins have a relatively small percentage of ponded to total accommodation. Two exceptions to this are the central portion of the Northwest Gulf of Mexico where ponded accommodation constitutes 55% of the total accommodation and the Kwanza Basin of Offshore Angola with 39% ponded accommodation. Shale-based systems may be more prone to bypass on the upper to mid slope than salt-based systems. Evidence for this is found in the linear grade trend analyses where large below-grade areas (sinks) are pervasive on the upper and mid slope of salt-based systems for deepwater sediment to accumulate, while shale-based systems show extensive above-grade highs across the entire slope. Ponded accommodation trends and drainage analyses also demonstrate that shale-based systems are more susceptible to extensive bypass than salt-based systems. The tectonically active margin of NW Borneo has steeper slope profiles than the passive margins, with areally small ponded accommodation largely restricted between active toe-thrusts on the lower slope and locally distributed on the shelf. These and other quantitative analyses suggest that the type of substrate and overall tectonic setting are important factors to consider for receiving basin configuration and its potential impact on deepwater sedimentation patterns. 相似文献