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1.
Within the central Mediterranean, the northwestern sector of the Sicily Channel is the unique area where two independent tectonic processes can be analyzed: the building of the Sicilian–Maghrebian Chain occurred in Late Miocene and the continental lithospheric rifting of the northern African margin occurred since Early Pliocene. These two geodynamic processes generated a peculiar structural style that is largely recognizable in the Adventure Plateau. This plateau is the shallowest part of the Sicily Channel, where water depths do not generally exceed 150 m. It hosts several areas of geomorphic relief, which in some cases rise up to less than 20 m beneath sea-level. A series of submarine magmatic manifestations occur in this area, mainly associated with the extensional phase which produced the rift-related depressions of Pantelleria, Malta and Linosa. Seismic-stratigraphic and structural analyses, based on a large set of multichannel seismic reflection profiles and well information acquired mostly for commercial purposes in the 1970s and 1980s, have allowed us to reconstruct the Triassic-Quaternary sedimentary succession of the Adventure Plateau and define its structural setting. A broad lithological distinction can be made between the successions ranging from Triassic to Paleogene, predominantly carbonate, and the successions ranging from Miocene to Quaternary, predominantly siliciclastic. Three main structural belts have been identified within the Adventure Plateau: (1) the northern belt, affected during Late Miocene time by ESE-verging thrusts belonging to the External Thrust System orogenic domain, which represents the lowermost structural level of the Sicilian–Maghrebian Orogen; (2) the Apenninic–Maghrebian domain of the Sicilian–Maghrebian Orogen, which occupies the northwestern sector of the Adventure Plateau, and that is overthrusted on the External Thrust System orogenic domain during the Late Miocene; (3) the extensional belt of the southwestern sector of the Adventure Plateau, affected by broad NW-trending, high-angle normal faults associated with the Early Pliocene continental rifting phase. The eastern boundary of the Adventure Plateau corresponds to a broadly N–S trending lithospheric transfer zone separating two sectors of the Sicily Channel characterized by a different tectonic evolution.  相似文献   

2.
The geological structures of the eastern Calabrian Apenninic front within the Gulf of Taranto, southern Italy, are compared to those of a convergent margin, using simple criteria such as the origin and volume of the sediment supply, and the relative ratio between sediments carried by the sinking plate and those directly supplied by the overriding margin. Based on this criteria we distinguish four main types of sedimentary accretion occurring at convergent continental margins: (a) Pacific type, (b) Indonesian type, (c) Caribbean type, and (d) Apenninic type.  相似文献   

3.
The geological structures of the eastern Calabrian Apenninic front within the Gulf of Taranto, southern Italy, are compared to those of a convergent margin, using simple criteria such as the origin and volume of the sediment supply, and the relative ratio between sediments carried by the sinking plate and those directly supplied by the overriding margin. Based on this criteria we distinguish four main types of sedimentary accretion occurring at convergent continental margins: (a) Pacific type, (b) Indonesian type, (c) Caribbean type, and (d) Apenninic type.  相似文献   

4.
渤中坳陷及邻区构造分带变形特征   总被引:1,自引:0,他引:1  
根据渤中坳陷及邻区的平面构造分布特征、剖面构造特征和布格重力异常等方面的资料分析,认为渤中坳陷及邻区构造具有分带性,从西向东可分为3个带:(1)西部凸起带:发育大量的凸起和断裂,凸起和凸起之间以小凹陷相隔,布格重力异常呈不规则团块状;(2)中部凹陷带:由渤中凹陷和辽中凹陷组成,很少发育凸起和断裂,布格重力异常呈等轴斑块状、椭圆状;(3)东部凸起带:由大量的凸起和凹陷相间组成,由于郯庐断裂的影响形成大量的断层,主要为走滑断裂及分支断裂,布格重力异常主要呈线状分布。这种构造分带性受郯庐断裂带的多期构造活动控制,对油气分布具有重要的影响,目前西部凸起带和东部凸起带由于长期处于构造的较高部位,已成为有利的油气勘探区。  相似文献   

5.
The Pacific-type orogeny in the Tohoku Island Arc is discussed using marine geological and geophysical data from both Pacific and Japan Sea along the Tohoku region. The Tohoku Arc is divided into three belts; inner volcanic and sedimentary belt, intermediate uplifted belt and outer sedimentary trench belt. Thick Neogene sediments which are distinguished in several layers by continuous seismic reflection profiling occur on both sides of the intermediate belt. The dominant structural trend of the Neogene layers is approximately parallel to the coast line and to the axis of the Japan Trench and has a extension of approximately 100 km in each unit on the Pacific side. The trench slope break is an uplifted zone of Neogene layers. The structural trend of the upper continental slope and outer shelf is relative uplift of the landward side. Tilted block movement toward the west is the dominant structural trend on the Japan Sea side. Structural trends which can be seen in both the inner and outer belts may suggest horizontal compressional stress of east to west. Orogenesis and tectogenesis in the Tohoku Arc has been active since early Miocene or latest Oligocene. It may be implied that the Japan Trench was not present during Late Cretaceous to Paleogene, as is suggested by the volcanism of the Tohoku Arc. The basic framework of the present structure was formed during late Miocene to early Pliocene in both the inner and outer belts. Structural movements were reactivated during late Pleistocene.  相似文献   

6.
1 Introduction D iapiric structures are an im portant andw idespread structural style in m any tectonic settings(Ism ail-Zadeh etal.,2001),including m agm a diapirs,salt diapirs, m ud diapirs, and serpentinite diapirs.C om pared w ith the form ertw o,m ud diapirism in sedi-m ents is rarely reported and studied although it hasbeen know n for a long tim e both on land and underthe sea.H ow ever,w ith the geologicalinvestigations ofO D P and related on-land studies of accretionaryprism s, m ud…  相似文献   

7.
南黄海盆地古潜山分类及构造特征   总被引:1,自引:0,他引:1  
南黄海是下扬子的主体,奠基于晋宁期变质基底之上,构造演化历经南华纪—早、中三叠世海相地层发育期、晚白垩世—古近纪箕状断陷发育期和新近纪—第四纪坳陷发育期,为一典型地台-断陷-坳陷多层结构的复合盆地。盆地历经多次构造运动改造,古潜山发育,类型多样。在总结前人对古潜山研究的基础上,结合南黄海新近采集的二维地震剖面,对该地区古潜山类型进行了系统划分,并对典型古潜山的构造特征及生储盖匹配关系进行了初步描述。根据成因划分为剥蚀型潜山、拉张型潜山、挤压型潜山和复合型潜山四大类,每一类又可根据形态划分出剥蚀残丘型潜山、拉张翘倾断块型潜山、拉张断阶型潜山、拉张断垒型潜山、挤压褶皱型潜山、拱张褶皱型潜山和褶皱—断块复合型潜山等类型。南黄海盆地古潜山的发育具有分带性,按盆地中潜山的构造位置,分为凸起潜山带、陡坡潜山带、洼陷潜山带和缓坡潜山带,每一构造带发育了不同类型潜山。研究表明南黄海古生界和中生界古潜山数量众多,规模较大,是南黄海地区实现油气突破的一种重要油气藏类型。  相似文献   

8.
深水褶皱冲断带是目前全球油气勘探的重要领域,其构造变形和油气地质特征是勘探研究的主要内容。通过对不同地区深水褶皱冲断带的地震剖面解释和综合分析,结合沉积特征对其构造样式、变形特征和石油地质特征进行了研究。研究表明,在主动大陆边缘和被动大陆边缘存在4种不同构造样式的深水褶皱冲断带,即:主动大陆边缘型深水褶皱冲断带;被动大陆边缘背景下的泥岩滑脱型、盐岩滑脱型和重力垮塌滑动型深水褶皱冲断带。由于他们具有不同的驱动机制、构造特征和演化特征,导致了其含油气性差别较大。主动大陆边缘背景下发育的深水褶皱冲断带主要发育倾向陆地的逆冲断层、叠瓦构造以及相关的褶皱构造,缺乏有效的烃源岩和储层。被动大陆边缘背景下发育的深水褶皱冲断带可以划分为伸展区、过渡区和挤压区3部分,并发育相关构造,其中泥岩滑脱型和盐岩滑脱型深水褶皱冲断带已经有大量的油气发现。  相似文献   

9.
We present a detailed stratigraphic and structural study of the Kopeh Dagh fold-and-thrust belt in NE Iran, which is an investigation of the complex polyphased tectonic history of this belt and its links with the adjacent South Caspian Sea and Amu Darya basins. Based on numerous field surveys, a large amount of 2D and 3D seismic data, borehole data and more than 150 new biostratigaphic datings, a new detailed biostratigraphic chart and 4 main regional cross-sections illustrate the importance of lateral facies variations and structural inheritance in the present-day structure of the belt.After the Cimmerian orogeny corresponding to the closure of the Paleotethys Ocean in Late Triassic/Early Jurassic times, a Middle Jurassic post-collisional rifting event was associated with the deposition of one of the main source rocks of the Kopeh Dagh and the Amu Darya Basin (Kashafrud Formation). Following this rifting event, over 7 km of sediments were accumulated until the Tertiary above a regional post-Triassic unconformity. The occurrence of local uplifts during the Late Cretaceous-Early Paleocene is interpreted as a consequence of regional-scale modification of plate-slab coupling in the Neotethys subduction zone. The main inversion of the Kopeh Dagh occurred at Late Eocene times, when the far-field deformation developed in Eurasia as a consequence of the locking of the Neo-Tethys subduction. This folding phase is sealed in the western part of the belt by a major Eocene-Oligocene unconformity at the base of the thick sedimentary series belonging to the South Caspian Sea Basin. The bulk of sedimentary infill in the South Caspian Sea Basin is Oligocene and younger, and it is probably related to syn-compressional downward flexure of the resistant basement basin at the onset of the Alpine phase. In the eastern part of the Kopeh Dagh, this deformation is characterized by Middle Jurassic graben inversion with evidence of forced folding, short-cuts and as well by larger scale basement uplifts. In contrast, the northwestern part of the belt shows thrust faults involving basement and fault-propagation folds within the sedimentary sequence. The Kopeh Dagh presents tectonic structures that are parallel to the Paleotethys suture zone, which emphasizes the importance of the structural inheritance and inversion processes during the structural evolution of the belt. Finally, a change from a mostly dip-slip to a mostly strike-slip tectonics occurred during the Pliocene within the Kopeh Dagh as a consequence of a major tectonic reorganization in North-East Iran.  相似文献   

10.
This Introduction presents an overview of selected contributions from the 11th Gas in Marine Sediments International Conference held on the 4–7 September 2012 in Nice, France, and published in this special issue of Geo-Marine Letters under the guest editorship of Catherine Pierre, Patrice Imbert and Jean Mascle. These cover fluid seepage dynamics at widely varying spatiotemporal scales in a giant buried caldera of the Caspian Sea, mud volcanoes and pockmarks in the Mediterranean and adjoining Gulf of Cadiz, as well as Lake Baikal, pockmarks of shallower waters along the Atlantic French coast and in Baltic Sea lagoons, deepwater pockmarks and cold seeps on the Norwegian margin and the Hikurangi Margin of New Zealand, asphalt seepage sites offshore southern California, and the tectonically controlled southern Chile forearc. We look forward to meeting all again at the 12th Gas in Marine Sediments conference scheduled for 1–6 September 2014 in Taipei, Taiwan.  相似文献   

11.
The investigation of complex geological setting is still dominated by traditional geo-data collection and analytical techniques, e.g., stratigraphic logging, dip data measurements, structural ground mapping, seismic interpretation, balance section restoration, forward modelling, etc. Despite the advantages of improving our understanding in structural geometry and fault architecture, the geospatial modelling, applying computer-aided three-dimensional geometric design, visualization and interpretation, has rarely been applied to such complex geological setting. This study used the Lenghu fold-and-thrust belt (in Qaidam basin, NE Tibetan Plateau) to demonstrate that the application of geospatial and geomechanical modelling could improve our understanding and provide an effective technique for investigating the fault architecture and strain distribution. The three-dimensional configuration of the Lenghu fold-and-thrust belt was initially derived from traditional analysis techniques, such as regional stratigraphic logging, cross section construction, meso-scale ground mapping and landsat image interpretation. The high-resolution field data and landsat image were integrated to construct the geospatial model, which was subsequently used to quantitatively investigate the fault throw changes along the Lenghu thrust fault zone and to understand its control on the lateral structural variation. The geospatial model was then restored in three dimensions to reveal the kinematic evolution of the Lenghu fold-and-thrust belt. Geomechanical modelling, using a Mass-Spring algorithm, provided an effective three-dimensional tool for structural strain analysis, which was used to predict the strain distribution throughout the overall structure, e.g., normal faults with throws ranging from meters to tens of meters in the hanging-wall. The strain distribution predicted by geomechanical modelling was then validated by the natural normal faults in the hanging-wall. The high accordance between the strain prediction and statistics of natural normal faults demonstrates good applicability of geospatial and geomechanical modelling in the complex geological setting of the Lenghu fold-and-thrust belt. The geospatial models and geomechanical models, therefore, can provide a robust technique for analyzing and interpreting multi-source data within a three-dimensional environment. We anticipate that the application of three-dimensional geospatial modelling and geomechanical modelling, integrating both multi-source geologic data and three-dimensional analytical techniques, can provide an effective workflow for investigating the fault architecture and strain distribution at different scales (e.g., ranging from regional-to meso-scale).  相似文献   

12.
从有机碳含量、可溶有机质含量及其转化率、热解参数、饱和烃的生物表示化合物特征、有机岩石学特征几个方面分析了民和盆地侏罗系烃源岩的有机质丰度、类型和成熟度,并进行了地球化学特征分析和生烃潜力评价。分析认为盆地发育湖相泥岩和煤系两大类烃源岩,有机质以较富含低等水生生物原始母质的腐泥腐殖型为主,主要分布于中侏罗统。通过对盆地石油地质条件的评价,结合各区带落实认识程度和资料品质条件认为:武家鼻隆构造带是最有利的勘探区带,万泉堡鼻状构造带具有良好勘探潜力,大庄构造带是寻找浅层次生油气藏的有利区带。永登凹陷面积大,资源丰富,勘探认识程度低,具有良好勘探前景。  相似文献   

13.
构造坡折带是由同沉积构造长期活动引起的沉积斜坡明显突变的地带,对盆地充填的可容纳空间和沉积作用可产生重要的影响,构造坡折带和油气资源分布有着较为密切的关系。隐蔽圈闭是沉积盆地油气勘探中后期重点勘探领域。构造坡折带是沉积盆地中隐蔽圈闭最发育的部位之一,多级构造坡折带组合对盆地隐蔽圈闭的发育有一定的影响,多级构造坡折带隐蔽圈闭发育更受到沉积环境和湖平面变化的影响;构造坡折带地区隐蔽圈闭油气成藏良好,高位域和三角洲前缘泥岩是良好的烃源岩,连片砂体和不整合界面及生长断裂是良好的输导条件,生长断裂和高位域泥岩具有良好的封盖作用。  相似文献   

14.
The Qiongdongnan Basin has the first proprietary high-yield gas field in deep-water areas of China and makes the significant breakthroughs in oil and gas exploration. The central depression belt of deep-water area in the Qiongdongnan Basin is constituted by five sags, i.e. Ledong Sag, Lingshui Sag, Songnan Sag, Baodao Sag and Changchang Sag. It is a Cenozoic extensional basin with the basement of pre-Paleogene as a whole. The structural research in central depression belt of deep-water area in the Qiongdongnan Basin has the important meaning in solving the basic geological problems, and improving the exploration of oil and gas of this basin. The seismic interpretation and structural analysis in this article was operated with the 3D seismic of about 1.5×10~4 km~2 and the 2D seismic of about 1×10~4 km. Eighteen sampling points were selected to calculate the fault activity rates of the No.2 Fault. The deposition rate was calculated by the ratio of residual formation thickness to deposition time scale. The paleo-geomorphic restoration was obtained by residual thickness method and impression method. The faults in the central depression belt of deep-water area of this basin were mainly developed during Paleogene, and chiefly trend in NE–SW, E–W and NW–SE directions. The architectures of these sags change regularly from east to west: the asymmetric grabens are developed in the Ledong Sag, western Lingshui Sag, eastern Baodao Sag, and western Changchang Sag; half-grabens are developed in the Songnan Sag, eastern Lingshui Sag, and eastern Changchang Sag. The tectonic evolution history in deep-water area of this basin can be divided into three stages,i.e. faulted-depression stage, thermal subsidence stage, and neotectonic stage. The Ledong-Lingshui sags, near the Red River Fault, developed large-scale sedimentary and subsidence by the uplift of Qinghai-Tibet Plateau during neotectonic stage. The Baodao-Changchang sags, near the northwest oceanic sub-basin, developed the large-scale magmatic activities and the transition of stress direction by the expansion of the South China Sea. The east sag belt and west sag belt of the deep-water area in the Qiongdongnan Basin, separated by the ancient Songnan bulge, present prominent differences in deposition filling, diaper genesis, and sag connectivity. The west sag belt has the advantages in high maturity, well-developed fluid diapirs and channel sand bodies, thus it has superior conditions for oil and gas migration and accumulation. The east sag belt is qualified by the abundant resources of oil and gas. The Paleogene of Songnan low bulge, located between the west sag belt and the east sag belt, is the exploration potential. The YL 8 area, located in the southwestern high part of the Songnan low bulge, is a favorable target for the future gas exploration. The Well 8-1-1 was drilled in August 2018 and obtained potential business discovery, and the Well YL8-3-1 was drilled in July 2019 and obtained the business discovery.  相似文献   

15.
莱州湾凹陷位于渤海南部海域,为中生界基底之上发育的新生代半地堑.郯庐断裂带分东西两支穿过莱州湾凹陷东部,在新生代盖层中表现出渤海最复杂最典型的为NNE向的右旋走滑断裂特征.其中东支断裂在渐新世以后活动强烈,发育多条NNE向走滑断层及NE向伴生断层组成的复杂断裂带.走滑断裂带内断层展布符合右旋单剪作用下的脆性走滑剪切模式,地震方差切片存在右旋运动拖拽断裂证据.通过对主断裂活动期次分析表明,研究区主要有三期大的构造活动,同时形成了三期构造反转.应力分布的局域性导致了形变特征的差异性,产生了褶皱、挤压反转、掀斜断块、花状构造等典型的构造类型.研究区首次利用三维地震资料对本区构造特征进行了分析,研究认为走滑活动形成了良好的构造背景、优越的油源及运移等成藏条件,具有较大的油气勘探潜力.  相似文献   

16.
针对深水区缺乏钻井资料的情况,从可以广泛获取的叠加速度出发建立了一套计算地下流体势(气势)的方法,并以此对琼东南盆地深水区进行了实例分析,以此来获得天然气运移和水合物成藏的有益信息。盆地广泛发育断裂、底辟构造,影响着水合物的分布。BSR发育区与气体势场强度的汇聚区域有着较好的对应关系,水合物根据成因可分为两类:一类是以浅部地层生物成因气为主,另一类是以深部热成因气为主。大部分断层对应于相对低势区,反映断层的开启性,可以作为气体运移的通道,其上部发育深部热成因气为主的水合物藏。在构造隆起附近发育的底辟具有相对高气势的特征,这类底辟携带大量的深部热成因气运移至浅部,为水合物的形成提供充足的气源,在其附近剖面上常具有BSR的显示。  相似文献   

17.
18.
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   

19.
南堡凹陷4号构造带蛤坨断层特征与油气成藏关系   总被引:1,自引:0,他引:1  
南堡凹陷4号构造带断裂发育,既发育沟通烃源岩的深断裂,也发育沟通浅层圈闭的次级断裂。综合利用地震、测井、岩性等资料分析断层的空间展布,计算蛤坨断层的生长指数和断层泥比率(SGR),分析断层的活动性、封堵性,评价其输导性能,并结合其与烃源岩生排烃期的匹配关系研究断裂与油气运移、聚集的关系及控制规律。在典型油气藏剖面解剖的基础上,建立了4号构造带油气运聚成藏模式。  相似文献   

20.
琼东南盆地中央坳陷带拆离断层及其控盆作用   总被引:4,自引:1,他引:3  
Using regional geological, newly acquired 2D and 3D seismic, drilling and well log data, especially 2D long cable seismic profiles, the structure and stratigraphy in the deep-water area of Qiongdongnan Basin are interpreted. The geometry of No.2 fault system is also re-defined, which is an important fault in the central depression belt of the deep-water area in the Qiongdongnan Basin by employing the quantitative analysis techniques of fault activity and backstripping. Furthermore, the dynamical evolution of the No.2 fault sys-tem and its controls on the central depression belt are analyzed. This study indicates that the Qiongdongnan Basin was strongly influenced by the NW-trending tensile stress field during the Late Eocene. At this time, No.2 fault system initiated and was characterized by several discontinuous fault segments, which controlled a series small NE-trending fault basins. During the Oligocene, the regional extensional stress field changed from NW-SE to SN with the oceanic spreading of South China Sea, the early small faults started to grow along their strikes, eventually connected and merged as the listric shape of the No.2 fault system as ob-served today. No.2 fault detaches along the crustal Moho surface in the deep domain of the seismic profiles as a large-scale detachment fault. A large-scale rollover anticline formed in hanging wall of the detachment fault. There are a series of small fault basins in both limbs of the rollover anticline, showing that the early small basins were involved into fold deformation of the rollover anticline. Structurally, from west to east, the central depression belt is characterized by alternatively arranged graben and half-graben. The central depression belt of the Qiongdongnan Basin lies at the extension zone of the tip of the V-shaped northwest-ern ocean sub-basin of the South China Sea, its activity period is the same as the development period of the northwestern ocean sub-basin, furthermore the emplacement and eruption of magma that originated from the mantle b  相似文献   

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