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1.
The NW–SE-striking Northeast German Basin (NEGB) forms part of the Southern Permian Basin and contains up to 8 km of Permian to Cenozoic deposits. During its polyphase evolution, mobilization of the Zechstein salt layer resulted in a complex structural configuration with thin-skinned deformation in the basin and thick-skinned deformation at the basin margins. We investigated the role of salt as a decoupling horizon between its substratum and its cover during the Mesozoic deformation by integration of 3D structural modelling, backstripping and seismic interpretation. Our results suggest that periods of Mesozoic salt movement correlate temporally with changes of the regional stress field structures. Post-depositional salt mobilisation was weakest in the area of highest initial salt thickness and thickest overburden. This also indicates that regional tectonics is responsible for the initiation of salt movements rather than stratigraphic density inversion.Salt movement mainly took place in post-Muschelkalk times. The onset of salt diapirism with the formation of N–S-oriented rim synclines in Late Triassic was synchronous with the development of the NNE–SSW-striking Rheinsberg Trough due to regional E–W extension. In the Middle and Late Jurassic, uplift affected the northern part of the basin and may have induced south-directed gravity gliding in the salt layer. In the southern part, deposition continued in the Early Cretaceous. However, rotation of salt rim synclines axes to NW–SE as well as accelerated rim syncline subsidence near the NW–SE-striking Gardelegen Fault at the southern basin margin indicates a change from E–W extension to a tectonic regime favoring the activation of NW–SE-oriented structural elements. During the Late Cretaceous–Earliest Cenozoic, diapirism was associated with regional N–S compression and progressed further north and west. The Mesozoic interval was folded with the formation of WNW-trending salt-cored anticlines parallel to inversion structures and to differentially uplifted blocks. Late Cretaceous–Early Cenozoic compression caused partial inversion of older rim synclines and reverse reactivation of some Late Triassic to Jurassic normal faults in the salt cover. Subsequent uplift and erosion affected the pre-Cenozoic layers in the entire basin. In the Cenozoic, a last phase of salt tectonic deformation was associated with regional subsidence of the basin. Diapirism of the maturest pre-Cenozoic salt structures continued with some Cenozoic rim synclines overstepping older structures. The difference between the structural wavelength of the tighter folded Mesozoic interval and the wider Cenozoic structures indicates different tectonic regimes in Late Cretaceous and Cenozoic.We suggest that horizontal strain propagation in the brittle salt cover was accommodated by viscous flow in the decoupling salt layer and thus salt motion passively balanced Late Triassic extension as well as parts of Late Cretaceous–Early Tertiary compression.  相似文献   

2.
青海木里三露天井田构造沉降史分析   总被引:1,自引:0,他引:1  
根据三露天井田的煤田钻孔和地质勘查报告等资料,应用回剥技术分析研究区从晚古生代石炭纪以来的沉降史及构造演化特征,讨论了水合物形成与构 造演化的关系。模拟结果显示,研究区自石炭纪以来主要经历了4期沉降和3期抬升:石炭纪至晚三叠世,沉降由慢转快,沉降幅度较大;晚三叠世末期,由于晚印支运动影响构造抬升;早侏 罗世至早白垩世,快速沉降;晚白垩世,燕山运动导致区域隆升;中新世发生较快速沉降;上新世受青藏高原隆升影响,快速隆升,随后第四纪又出现较快速沉降。沉降史模拟结果为研究区 构造演化提供了定量或半定量的参数。三露天构造沉降对天然气水合物形成的控制作用体现在影响烃源岩成熟度和温压稳定带的形成两方面。  相似文献   

3.
The Roer Valley Rift System (RVRS) is located between the West European rift and the North Sea rift system. During the Cenozoic, the RVRS was characterized by several periods of subsidence and inversion, which are linked to the evolution of the adjacent rift systems. Combination of subsidence analysis and results from the analysis of thickness distributions and fault systems allows the determination of the Cenozoic evolution and quantification of the subsidence. During the Early Paleocene, the RVRS was inverted (Laramide phase). The backstripping method shows that the RVRS was subsequently mainly affected by two periods of subsidence, during the Late Paleocene and the Oligocene–Quaternary time intervals, separated by an inversion phase during the Late Eocene. During the Oligocene and Miocene periods, the thickness of the sediments and the distribution of the active faults reveal a radical rotation of the direction of extension by about 70–80° (counter clockwise). Integration of these results at a European scale indicates that the Late Paleocene subsidence was related to the evolution of the North Sea basins, whereas the Oligocene–Quaternary subsidence is connected to the West European rift evolution. The distribution of the inverted provinces also shows that the Early Paleocene inversion (Laramide phase) has affected the whole European crust, whereas the Late Eocene inversion was restricted to the southern North Sea basins and the Channel area. Finally, comparison of these deformations in the European crust with the evolution of the Alpine chain suggests that the formation of the Alps has controlled the evolution of the European crust since the beginning of the Cenozoic.  相似文献   

4.
More than 1400 km of two-dimensional seismic data were used to understand the geometries and structural evolution along the western margin of the Girardot Basin in the Upper Magdalena Valley. Horizons are calibrated against 50 wells and surface geological data (450 km of traverses). At the surface, low-angle dipping Miocene strata cover the central and eastern margins. The western margin is dominated by a series of en echelon synclines that expose Cretaceous–Oligocene strata. Most synclines are NNE–NE trending, whereas bounding thrusts are mainly NS oriented. Syncline margins are associated mostly with west-verging fold belts. These thrusts started deformation as early as the Eocene but were moderately to strongly reactivated during the Andean phase. The Girardot Basin fill records at least four stratigraphic sequences limited by unconformities. Several periods of structural deformation and uplifting and subsidence have affected the area. An early Tertiary deformation event is truncated by an Eocene unconformity along the western margin of the Girardot Basin. An Early Oligocene–Early Miocene folding and faulting event underlies the Miocene unconformity along the northern and eastern margin of the Girardot Basin. Finally, the Late Miocene–Pliocene Andean deformation folds and erodes the strata along the margins of the basin against the Central and Eastern Cordilleras.  相似文献   

5.
渭河盆地、渭北隆起及东秦岭造山带地处青藏块体东北缘、华北克拉通和扬子克拉通的交界处,形成了特有的盆山体系,分布有油气、氦气及地热等多种能源矿产资源。新生代是渭河盆地沉积-构造演化及渭北隆起和东秦岭隆升的重要时期,缺乏该时期盆山体系耦合关系的研究,制约了对区域矿产资源分布规律的认识。盆山耦合体现在时间、空间、物质、构造作用及地表形态等多方面。以大量钻孔资料为依托,运用“回剥法”分析了渭河盆地新生代的沉降幅度及沉降速率,并根据主沉降期新近纪以来不同阶段沉积地层厚度展布特征恢复了盆地沉积演化历史。研究表明渭河盆地新生代以来沉降中心具有自西南方向西安凹陷向北东方向固市凹陷迁移的特征。古近纪始新世以来,渭河盆地发生快速构造沉降,中新世早-中期以西安凹陷为主要沉积、沉降中心,晚中新世以来以西安、固市两个凹陷为主要沉积、沉降中心,晚上新世-早更新世沉降中心转移到东北部固市凹陷,晚更新世以来,西安凹陷和固市凹陷均发生快速沉降。裂变径迹的分析测试结果表明渭北隆起约45~32 Ma整体快速抬升,同步于东秦岭太白山和华山约57~40 Ma的快速隆升阶段,与渭河盆地古近纪始新世约40 Ma的基底快速沉降具有耦合关系。晚中新世约7.3 Ma以来,渭河盆地的持续快速沉降,与渭北隆起上新世约5 Ma及东秦岭太白山约10~9.6 Ma、华山约8~5 Ma以来的快速耦合关系明显。太平洋板块的俯冲、欧亚板块与印度板块始新世约55~45 Ma碰撞及青藏高原约10~8 Ma隆升外扩的远程效应对研究区影响较大。  相似文献   

6.
Problems of geodynamics, tectonics, and metallogeny of orogens   总被引:1,自引:0,他引:1  
This is an overview of papers published in the present volume of Russian Geology and Geophysics (Geologiya i Geofizika), a special issue that covers presentations at the International Conference “Geodynamic Evolution, Tectonics, and Metallogeny of Orogens”, held on 28–30 June 2010 in Novosibirsk (http://altay2010.igm.nsc.ru). The workshop concerned the general evolution of the Central Asian orogenic system, with a special focus on continental growth, history of oceans and continental margins, and role of plumes in accretionary-collisional tectonics and metallogeny. The discussed papers are grouped in three sections: 1. General issues of geodynamics and geodynamic evolution; 2. Role of mantle plumes in tectonics, magmatism, and metallogeny; 3. Regional tectonic and geodynamic problems of Asia.The synthesis of data reported at the workshop demonstrates critical importance of mantle plumes for the evolution of the Paleoasian ocean and for orogenic processes in Central Asia.In addition to three large pulses of continental growth at about 2900–2700, 1900–1700, and 900–700 Ma, three orogenic stages have been distinguished in the geological history of Eurasia: Late Cambrian–Ordovician (510–470 Ma), Late Devonian–Early Carboniferous (380–320 Ma), and Permian–Triassic (285–230 Ma). In the evolution of the Central Asian orogen, these stages were associated with events of ultramafic-mafic and bimodal plume magmatism which promoted translithospheric strike-slip faulting. Plume magmatism was an active agent in ocean opening when the Paleotethys, Ural, Ob–Zaisan, and Turkestan basins appeared while the Late Cambrian–Ordovician orogen was forming in Central Asia (North Kazakhstan, Altai–Sayan, Tuva, and Baikal areas). Closure of the Ob–Zaisan ocean and collision of the Kazakhstan–Baikal continent with Siberia in the Late Devonian–Early Carboniferous was coeval with the maximum opening of the Turkestan ocean, possibly, as a consequence of plume activity. The Tarim (285–275 Ma) and Siberian (250–230 Ma) superplume events corresponded in time to closure of the Ural ocean and opening of the Meso- and Neotethys, as well as to major metallogenic events.  相似文献   

7.
银川盆地构造反转及其演化与叠合关系分析   总被引:3,自引:0,他引:3       下载免费PDF全文
以银川盆地构造反转为研究对象,从构造反转证据、反转时期以及反转强度等方面进行了分析,以此为基础,探讨 了银川盆地中生代以来构造演化。研究表明:负反转构造的发育、新生界与中-古生界地层展布特征的差异性以及伸展构 造样式与挤压构造样式并存等方面证明银川盆地发生负反转;构造反转的挤压隆升时期为晚侏罗世,伸展沉降期为渐新世 至新近纪;银川盆地北部构造反转强度大于南部,西部反转强度大东部;银川盆地自中生代以来经历了三叠纪至早-中侏 罗世时期的整体沉降、晚侏罗世的挤压隆升与差异剥蚀、早白垩世的再次沉降、白垩纪末期至新生代早期的整体隆升剥 蚀、渐新世至新近纪的快速断陷以及第四纪的整体拗陷六个演化叠合阶段。  相似文献   

8.
砾岩相通常作为构造事件的标志,对探讨造山带隆升过程有着重要的意义.选取位于帕米尔构造带东北缘的奥依塔格剖面开展砾石统计分析.新生代不同时期砾石的统计结果显示,奥依塔格剖面砾石成分主要为火成岩和变质岩,这与帕米尔造山带岩性相符.其中,花岗岩砾石作为特征组分首次出现在上新统阿图什组底部.砾石主要为巨砾,且以长短轴比值为1~2的近圆状为主;砾石的磨圆度中等,绝大部分为次磨圆-次棱角状;分选中等-差.结合砾石所处地层的沉积环境和热年代学记录,认为帕米尔东北缘新生代可能存在3期构造隆升事件,包括渐新-中新世克孜洛依组沉积早期、中新世中期(安居安组中-上段和帕卡布拉克组下段沉积时期)和上新世以来(阿图什组下段沉积以来).   相似文献   

9.
Notes de lecture     
Abstract

3D stratigraphic geometries of the intracratonic Meso- Cenozoic Paris Basin were obtained by sequence stratigraphic correlations of around 1 100 wells (well-logs). The basin records the major tectonic events of the western part of the Eurasian Plate, i.e. opening and closure of the Tethys and opening of the Atlantic. From earlier Triassic to Late Jurassic, the Paris Basin was a broad subsiding area in an extensional framework, with a larger size than the present-day basin. During the Aalenian time, the subsidence pattern changes drastically (early stage of the central Atlantic opening). Further steps of the opening of the Ligurian Tethys (base Het- tangian, late Pliensbachian;...) and its evolution into an oceanic domain (passive margin, Callovian) are equally recorded in the tectono-sedimentary history. The Lower Cretaceous was characterized by NE-SW compressive medium wavelength unconformities (late Cimmerian-Jurassic/Cretaceous boundary and intra- Berriasian and late Aptian unconformities) coeval with opening of the Bay of Biscay. These unconformities are contemporaneous with a major decrease of the subsidence rate. After an extensional period of subsidence (Albian to Turanian), NE-SW compression started in late Turanian time with major folding during the Late Cretaceous. The Tertiary was a period of very low subsidence in a com- pressional framework. The second folding stage occurred from the Lutetian to the Lower Oligocene (N-S compression) partly coeval with the E-W extension of the Oligocene rifts. Further compression occurred in the early Burdigalian and the Late Miocene in response to NE-SW shortening. Overall uplift occurred, with erosion, around the Lower/Middle Pleistocene boundary. © 2000 Éditions scientifiques et médicales Elsevier SAS  相似文献   

10.
鄂尔多斯盆地周边地带新构造演化及其区域动力学背景   总被引:21,自引:0,他引:21  
系统研究了松辽盆地泰康地区青山口组沉积相类型及沉积特征.对其中青一段与青二、三段的沉积相平面分布与垂向演化规律做了较深入的探讨.青山口组主要发育湖泊相与三角洲相2种沉积相类型,湖泊相包括2种亚相与4种微相,三角洲相包括2种亚相和2种微相.青一段以深湖、半深湖相泥岩沉积为特征,青二、三段以浅湖相与三角洲相砂泥岩互层为特征.区内青山口组主要存在3种类型的储层砂体,分别为三角洲前缘河口坝砂体、三角洲前缘远砂坝砂体和浅湖砂体,其中浅湖砂体是最好的含油砂体,浅湖砂体发育的优势区也即浅湖沉积亚相发育区是区内最重要的油气富集区,是今后油气勘探的有利地区  相似文献   

11.
Sheets of salt and ductile shale advancing beyond the thrust front of the Gibraltar Arc (Iberian–Moroccan Atlantic continental margin) triggered downslope movements of huge allochthonous masses. These allochthons represent the Cádiz Nappe, which detached from the Gibraltar Arc along low‐angle normal faults and migrated downslope from the Iberian and Moroccan continental margins towards the Atlantic Ocean. Extensional tectonics initiated upslope salt withdrawal and downslope diapirism during large‐scale westward mass wasting from the shelf and upper slope. Low‐angle salt and shale detachments bound by lateral ramps link extensional structures in the shelf to folding, thrusting and sheets of salt and shale in the Gulf of Cádiz. From backstripping analyses carried out on the depocentres of the growth‐fault‐related basins on the shelf, we infer two episodes of rapid subsidence related to extensional collapses; these were from Late Tortonian to Late Messinian (200–400 m Myr?1) and from Early Pliocene to Late Pliocene (100–150 m Myr?1). The extensional events that induced salt movements also affected basement deformation and were, probably, associated with the westward advance of frontal thrusts of the Gibraltar Arc as a result of the convergence between Africa and Eurasia. The complexities of salt and/or shale tectonics in the Gulf of Cádiz result from a combination of the deformations seen at convergent and passive continental margins.  相似文献   

12.
方鹏高  丁巍伟  方银霞  赵中贤 《地球科学》2015,40(12):2052-2066
为了探索碳酸盐台地在海盆演化过程中的作用,对南海南部礼乐滩区域碳酸盐台地的发育及其与新生代构造沉降特征的相关性进行研究.对多道地震数据的分析表明:在研究区广泛发育包括碳酸盐台地和生物礁在内的碳酸盐沉积,其发育时间主要集中在晚渐新世至早中新世期间,在中中新世后开始退积和淹没.通过对穿越礼乐滩区的两条NW-SE向测线NH973-2和DPS93-2的构造沉降反演,进行沉降量、沉降速率计算和构造分析.结果表明:沉降速率及沉降量随不同时期的构造活动而发生变化,可分为缓慢沉降期(古新世-早渐新世,张裂阶段)、隆升剥蚀期(晚渐新世-早中新世,漂移阶段)、加速沉降期(早中新世末期,后漂移阶段1)、强烈沉降期(中新世,后漂移阶段2)和稳定沉降期(晚中新世至今,后漂移阶段3)5个发育期.碳酸盐台地的发育期和南海海盆的漂移阶段相对应,构造沉降的分析表明该期间具有构造抬升作用,其与相对上升的海平面结合有利于碳酸盐沉积的发育.在南海扩张期间主地幔对流的控制下,南部陆缘区礼乐地块和礼乐滩盆地之间较大的地壳厚度差异会导致侧向上地温梯度的差异,从而形成礼乐滩盆地之下的次生对流.该次生对流控制了研究区在晚渐新世至早中新世期间的隆升剥蚀作用.   相似文献   

13.
The sedimentary pattern of the southern Gulf of Suez, Egypt, especially during the Cenozoic rift stage, was controlled mainly by tectonic activities (subsidence and uplift) and sea level change. The stratigraphic record of the southern Gulf of Suez can be divided into two megasequences: pre-rift and syn-rift. The pre-rift megasequence can be viewed as two distinctive depositional regimes, clastic rocks of continental to braided stream environment during Cambrian and open marine transgression extended from Upper Cretaceous till Eocene. The syn-rift deposits showed a distinctive contrast between the depocenter and peripheral basins. This difference can be shown clearly on the sedimentary sequence of Hilal and Shoab Ali oilfields. The syn-rift megasequence can be differentiated in relation to rift evolution into the following stages: initial rift stage with low subsidence rate, main rift stage with maximum subsidence rate, quiescence stage with the slowest subsidence rate throughout the rift evolution, evaporite stage with restriction conditions, and Pliocene–Recent stage with shallow marine condition.  相似文献   

14.
2007年中国在南海北部神狐海域通过钻探首次获得天然气水合物样品,证实了珠江口盆地深水区是水合物富集区。通过对珠江口盆地深水区构造沉降史的定量模拟研究,发现晚中新世以来区内构造沉降总体上具有由北向南、自西向东逐渐变快的演化趋势;从晚中新世到更新世,盆地深水区经历了构造沉降作用由弱到强的变化过程:晚中新世(11.6~5.3 Ma),平均构造沉降速率为67 m/Ma;上新世(5.3~1.8 Ma),平均构造沉降速率为68 m/Ma;至更新世(1.8~0 Ma),平均构造沉降速率为73 m/Ma。而造成这些变化的主因是发生在中中新世末-晚中新世末的东沙运动和发生在上新世-更新世早期的台湾运动。东沙运动(10~5 Ma)使盆地在升降过程中发生块断升降,隆起剥蚀,自东向西运动强度和构造变形逐渐减弱,使得盆地深水区持续稳定沉降;台湾运动(3 Ma)彻底改变了盆地深水区的构造格局,因重力均衡调整盆地深水区继续沉降,越往南沉降越大。将似海底反射(BSR)发育区与沉降速率平面图进行叠合分析,发现80%以上的BSR分布趋于构造沉降速率值主要在75~125 m/Ma之间、沉降速率变化迅速的隆坳接合带区域。  相似文献   

15.
The Iberian Chain is a wide intraplate deformation zone formed by the tectonic inversion during the Pyrenean orogeny of a Permian–Mesozoic basin developed in the eastern part of the Iberian Massif. The N–S convergence between Iberia and Eurasia from the Late Cretaceous to the Lower Miocene times produced significant intraplate deformation. The NW–SE oriented Castilian Branch of the Iberian Chain can be considered as a “key zone” where the proposed models for the Cenozoic tectonic evolution of the Iberian Chain can be tested. Structural style of basin inversion suggests mainly strike–slip displacements along previous NW–SE normal faults, developed mostly during the Mesozoic. To confirm this hypothesis, structural and basin evolution analysis, macrostructural Bouguer gravity anomaly analysis, detailed mapping and paleostress inversions have been used to prove the important role of strike slip deformation. In addition, we demonstrate that two main folding trends almost perpendicular (NE–SW to E–W and NW–SE) were simultaneously active in a wide transpressive zone. The two fold trends were generated by different mechanical behaviour, including buckling and bending under constrictive strain conditions. We propose that strain partitioning occurred with oblique compression and transpression during the Cenozoic.  相似文献   

16.
Neotectonic observations allow a new interpretation of the recent tectonic behaviour of the outer fore arc in the Caldera area, northern Chile (27°S). Two periods of deformation are distinguished, based on large-scale Neogene to Quaternary features of the westernmost part of the Coastal Cordillera: Late Miocene to Early Pliocene deformations, characterized by a weak NE–SW to E–W extension is followed by uppermost Pliocene NW–SE to E–W compression. The Middle Pleistocene to Recent time is characterized by vertical uplift and NW–SE extension. These deformations provide clear indications of the occurrence of moderate to large earthquakes. Microseismic observations, however, indicate a lack of shallow crustal seismicity in coastal zone. We propose that both long-term brittle deformation and uplift are linked to the subduction seismic cycle.  相似文献   

17.
云南曲靖盆地构造演化及其对生物气成藏条件的控制   总被引:1,自引:0,他引:1  
侯宇光  何生  唐大卿 《现代地质》2006,20(4):597-604
曲靖盆地是在云南省发现的具有工业价值生物气藏的第三系沉积盆地之一。利用二维地震测线结合地质和钻井等资料开展了详细的构造和沉积解释,对曲靖盆地的构造特征、盆地形成和演化进行了较为系统的综合研究,分析了构造演化对生物气成藏条件的控制作用。曲靖盆地的早—中渐新世的断陷阶段为大套湖相暗色泥岩(蔡家冲组)形成时期;渐新世晚期—上新世早期为盆地整体抬升萎缩阶段,避免了蔡家冲组有机质的大量消耗,保存了第四纪以来生物气成藏的有机物质;晚上新世的盆地坳陷阶段为茨营组含煤层系(次要气源岩)、储集层、盖层和岩性圈闭形成的主要时期;上新世末的压扭抬升萎缩阶段是断背斜和断鼻等构造圈闭和构造—岩性复合圈闭发育时期;第四纪盆地稳定沉降阶段为生物气聚集成藏时期。  相似文献   

18.
The Central European Basin System (CEBS) is composed of a series of subbasins, the largest of which are (1) the Norwegian–Danish Basin (2), the North German Basin extending westward into the southern North Sea and (3) the Polish Basin. A 3D structural model of the CEBS is presented, which integrates the thickness of the crust below the Permian and five layers representing the Permian–Cenozoic sediments. Structural interpretations derived from the 3D model and from backstripping are discussed with respect to published seismic data. The analysis of structural relationships across the CEBS suggests that basin evolution was controlled to a large degree by the presence of major zones of crustal weakness. The NW–SE-striking Tornquist Zone, the Ringkøbing-Fyn High (RFH) and the Elbe Fault System (EFS) provided the borders for the large Permo–Mesozoic basins, which developed along axes parallel to these fault systems. The Tornquist Zone, as the most prominent of these zones, limited the area affected by Permian–Cenozoic subsidence to the north. Movements along the Tornquist Zone, the margins of the Ringkøbing-Fyn High and the Elbe Fault System could have influenced basin initiation. Thermal destabilization of the crust between the major NW–SE-striking fault systems, however, was a second factor controlling the initiation and subsidence in the Permo–Mesozoic basins. In the Triassic, a change of the regional stress field caused the formation of large grabens (Central Graben, Horn Graben, Glückstadt Graben) perpendicular to the Tornquist Zone, the Ringkøbing-Fyn High and the Elbe Fault System. The resulting subsidence pattern can be explained by a superposition of declining thermal subsidence and regional extension. This led to a dissection of the Ringkøbing-Fyn High, resulting in offsets of the older NW–SE elements by the younger N–S elements. In the Late Cretaceous, the NW–SE elements were reactivated during compression, the direction of which was such that it did not favour inversion of N–S elements. A distinct change in subsidence controlling factors led to a shift of the main depocentre to the central North Sea in the Cenozoic. In this last phase, N–S-striking structures in the North Sea and NW–SE-striking structures in The Netherlands are reactivated as subsidence areas which are in line with the direction of present maximum compression. The Moho topography below the CEBS varies over a wide range. Below the N–S-trending Cenozoic depocentre in the North Sea, the crust is only 20 km thick compared to about 30 km below the largest part of the CEBS. The crust is up to 40 km thick below the Ringkøbing-Fyn High and up to 45 km along the Teisseyre–Tornquist Zone. Crustal thickness gradients are present across the Tornquist Zone and across the borders of the Ringkøbing-Fyn High but not across the Elbe Fault System. The N–S-striking structural elements are generally underlain by a thinner crust than the other parts of the CEBS.The main fault systems in the Permian to Cenozoic sediment fill of the CEBS are located above zones in the deeper crust across which a change in geophysical properties as P-wave velocities or gravimetric response is observed. This indicates that these structures served as templates in the crustal memory and that the prerift configuration of the continental crust is a major controlling factor for the subsequent basin evolution.  相似文献   

19.
叶城盆地属于塔里木盆地的西南坳陷 ,在晚新生代沉积了巨厚的磨拉石建造。盆地的演化具有阶段性 ,反映了西昆仑山不断的隆升。中新世 ,盆地的沉积环境为曲流河和辨状河等河湖相环境 ,到上新世早期变为冲积扇的远端。晚上新世 (~ 3.6 Ma)开始 ,盆地的沉积环境发生了质的变化 ,沉积物以粗颗粒砾岩为主 ,沉积环境为干旱气候条件下的冲 -洪积扇近端。沉积相的变化 ,反映了昆仑山在晚上新世有强烈的隆升。  相似文献   

20.
库车坳陷沉降与天山中新生代构造活动   总被引:13,自引:0,他引:13  
位于塔里木盆地北缘、天山南侧的库车坳陷为中新生代发育的构造单元。坳陷与天山造山带在成因上紧密相连,坳陷的沉降是由于天山山体隆升扩展引起的岩石圈挠曲响应。根据纵横向不同位置盆地沉降史的分析对比,该坳陷为典型的挤压盆地。推测中生代时期天山造山带以走滑和逆冲作用为主,新生代时期至少在库车坳陷北缘,天山造山带以向南冲断作用为主。库车坳陷强烈沉降时期并不对应于粗碎屑沉积,而对应于细碎屑沉积时期,即天山造山带构造强烈活动时期。天山造山带强烈活动造成库车坳陷强烈沉降,其主要原因与塔里木板块南侧的羌塘地体、拉萨地体、科西斯坦杂岩和印度次大陆的增生碰撞有关。  相似文献   

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