印度-欧亚板块碰撞对南海形成的影响研究: 一种数值模拟方法   总被引：2，自引：0，他引：2  

谢建华  夏斌  张宴华  王喜臣  林洁梅 《海洋通报》2005,24(5):47-53

中国南海新生代处于欧亚板块、印度-澳大利亚板块和太平洋板块相互作用的交汇处,其形成演化受三大板块复杂动力学过程和相互间作用所制约,尤其是中始新世印度板块同欧亚板块之间的“硬”碰撞及随后的楔入的影响.利用FLAC软件对该次碰撞对南海形成效应进行了模拟,模拟结果表明在模型东-东南边界为自由边界和考虑太平洋向欧亚板块的俯冲作用的支持应力边界条件两种情形下,均能引起构造物质或地幔流向南东、南逃逸,在南海地区产生足够的侧向挤出和南北向的剪切,从而在该地区导致广泛的南北向拉张,这些极有利于南海的打开.  相似文献   

Improved environmental contour methods based on an optimization of hybrid models     

《Applied Ocean Research》2019

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Rift–shear architecture and tectonic development of the Ghana margin deduced from multichannel seismic reflection and potential field data     

A.A. Antobreh  J.I. Faleide  F. Tsikalas  S. Planke 《Marine and Petroleum Geology》2009

The Ghana margin displays one of the best-known transform margins. Studies of the margin have provided the framework for a number of conceptual models aimed at understanding transform margin development worldwide. However, the deep structure of the margin is poorly known as knowledge is based only on wide-angle refraction measurements obtained from two separate localities on the margin. Consequently, complexities in the rift–shear margin architecture have been overlooked by current interpretations of margin development. Based on combined analysis of a detailed grid of ∼2710 km multichannel (MCS) lines and potential field data, we provide new insights into the structural architecture and tectonic development of the Ghana margin. In particular, we outline the deep structure of the entire margin using a series of 2D gravity modelled transects constrained by MCS and published wide-angle data. Our study reveals more complex rift–shear margin architecture than previously envisaged. We demonstrate that the main transform boundary representing the continental extension of the Romanche Fracture Zone, is actually composed of two distinct margin segments, i.e., the ENE–WSW trending sheared margin segment of the Cote d’Ivoire-Ghana Ridge and the NE–SW trending rift-influenced sheared margin segment of the Ghana Platform. These segments evolved under varying stress regimes, and during different time intervals. West of the transform margin, divergent rifting during the Early Cretaceous initiated the development of the Deep Ivorian Basin, essentially, as a single major pull-apart structure. However, east of the shear zone, oblique rifting resulted in the development of the Eastern Ghana Slope Basin as a composite of at least two coalescing pull-apart basins displaced along strike-slip faults. Our structural interpretation of the transform boundary geometry shows that the ridge and platform margin segments were each subjected to separate thermal influences from two different migrating spreading centres. Tectonic uplift of the ridge began through transpression during mid-Albian time following a change in relative direction of plate motion from NE–SW to ENE–WSW. However, the ridge uplift was amplified by thermal heating from a previously undocumented spreading centre whose progressive westward migration along the ridge followed closely after the Albian transpressional phase. The structural architecture of the Ghana margin resulted from a combination of factors, notably, pre-existing basement structure, plate boundary geometry, the relative direction of plate motion and thermal heating.  相似文献   

国外边际地区及边际化过程研究述评     

王爱民  陈树荣  马学广 《地球科学进展》2007,22(2):159-166

自20 世纪80 年代以来,国外学者从侧重于核心区的研究扩展到对山区及高纬地区、边界边远地区、脆弱生态环境地区和欠发达地区等区域的研究。90 年代以后,随着理论探讨的深入,具有上述特征的不同区域在边际地区这一术语下得以进一步地提升和整合。近年来国际地理学界对边际地区的概念与理论、典型边际地区与边际化过程、边际地区的区域响应与全球化响应、边际地区发展问题等方面进行了多视角的研究。与“核心区”、“兴盛区”及其“空间极化”相呼应,“边际地区”和“边际化过程”对“危急—问题区”及其机理提供了一套理论解释,展现出地理学空间差异和空间关系研究新的视角。  相似文献   

The application of electrical resistivity tomography and gravimetric survey as useful tools in an active tectonics study of the Sudetic Marginal Fault (Bohemian Massif, central Europe)     

Petra &#x;tpan íkov  Ji&#x;í Dohnal  Tom&#x; Pnek  Monika &#x;j  Veronika Smolkov  Karel &#x;ilhn 《Journal of Applied Geophysics》2011,74(1):69-80

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生物标志物重建浮游植物生产力及群落结构研究进展   总被引：1，自引：0，他引：1  

丁玲  邢磊  赵美训 《地球科学进展》2010,25(9):981-989

海洋浮游植物生产力和群落结构在地质年代中的变化对深入理解碳循环的演变规律和机理有着重要的意义.生物标志物方法作为一种较新的研究手段,其含量与比值的变化被广泛用于浮游植物生产力与群落结构变化的重建.讨论了生物标志物方法在各大洋及我国边缘海的应用现状,提出了生物标志物的细胞产生量及其在环境中的保存效率的2种主要不确定因素,使目前多参数生物标志物方法只能够半定量地重建古生产力与群落结构的变化.针对我国边缘海,提出有必要通过现场调查和实验室培养建立生物标志物含量(比值)与浮游植物生产力(群落结构)的定量关系式,以达到能够定量重建生产力和群落结构变化的目的.  相似文献   

Structural geology of the Huldra Field, northern North Sea—a major tilted fault block at the eastern edge of the Horda Platform     

Haakon Fossen  Jonny Hesthammer  Tord Erlend Skeie Johansen  Trond Olav Sygnabere 《Marine and Petroleum Geology》2003,20(10):1105-1118

The Huldra fault block is a rotated major fault block on the east margin of the Viking Graben in the northern North Sea. Unlike the rest of the Horda Platform area, the Jurassic section in the Huldra fault block was rotated more than 20° during slip on the listric Huldra fault, which forms a low-angle detachment beneath the Huldra fault block. The fault block is interpreted as resulting from marginal collapse of the Horda Platform after relief along the eastern margin of the Viking Graben built up in early parts of the middle to late Jurassic rifting history. The collapse resulted in NW directed transport of the Huldra fault block, consistent with a previously postulated change in extension direction from W–E to NW–SE toward the end of the Jurassic period. Minor faults within the Hulrda fault block are consistent with E–W extension and thus may have formed early during the late Jurassic rifting phase. Nevertheless, the crest (Huldra Field) seems surprisingly intact, considering its proximity to a major fault zone. Deformation bands studied from core material are non-cataclastic and concentrated in zones. Evidence for smearing along a cored fault surface indicates that minor subseismic faults may be sealing. Production data from the field indicate good communication between most wells, suggesting that the subseismic faults and deformation band zones that are present in the reservoir have relatively small influence on the flow of gas in the reservoir.  相似文献   

地块－海槽边缘带成油成气新概念     

罗斌杰  郑国东  杨醒华  段毅 《地球科学进展》1996,(3)

对准噶尔、塔里木等盆地沉积环境的研究表明,古生代时,中国西北区为海相沉积,沉积盆地的基底是一些离散的古老结晶地块,其上海水侵漫,地块之间为大洋或窄大洋的海槽。地块之间的海槽或地块与海槽过渡的边缘带盆地是油气形成的有利地带。在海槽遭受压缩褶皱而回返的造山过程中,＂地块－海槽＂体系发生转化,形成中新生代＂山系－盆地＂的陆相沉积体系。边缘带的油气源岩系被埋藏在盆地外围的山系之下。但其中形成的部分油气已运移到盆地内的储集层中聚集,形成＂外生内储＂的油气藏。在这种类型的盆地中,存在陆相生油和海相生油、＂内生内储＂和＂外生内储＂的两类生油岩系和两种生储组合配置体系。这一油气形成分布的理论,已不断地被油气地球化学研究和勘探实践所证实。＂地块－海槽＂边缘带油气形成观点的提出,突破了以现今盆地为界限研究古生代油气形成分布规律的传统观念,增大了中国西北区可以发现的油气资源量,扩展了找油找气的新领域,具有十分重要的意义。  相似文献   

由多卫星测高大地水准面推断西太平洋边缘海构造动力格局   总被引：3，自引：1，他引：3       下载免费PDF全文

高金耀  金翔龙 《地球物理学报》2003,46(5):600-608

由于卫星观测技术的发展，现在已能利用测高大地水准面简捷可靠地研究海底构造与动力问题. 根据Geosat T2/ERM、Topex/Poseidon 和ERS 1/2测高数据给定的0°N ～45°N、100°E～150°E范围内4′×4′大地水准面，采用全球地形/均衡的重力位效应改正，计算布格、格莱尼和均衡大地水准面. 由格莱尼大地水准面反演Moho面埋深，再从均衡大地水准面起伏推算小尺度地幔流应力场. 结果表明，菲律宾海和南海显示了与磁条带、扩张脊对应或斜交的高频成分大地水准面起伏条带. 各边缘海盆的Moho面埋深有往南变浅的趋势，与菲律宾海各海盆的Moho面埋深大致相当，说明琉球—台湾—菲律宾岛弧两侧的构造动力强度基本相近. 从各种构造特征和大、中、小尺度的地幔流应力场的驱动机制，可以证明岛弧内侧的边缘海具有不同于大洋、大陆的独特构造动力格局和特征.  相似文献   

内蒙古奈曼农田的微气象特征   总被引：1，自引：0，他引：1  

李胜功  原薗芳信  何宗颖  申建友 《气象》1995,21(6):29-32

运用波文比热量平衡法分析了内蒙古奈曼麦田、谷田、大豆田和稻田的微气象特征。结果表明：随着小麦生长趋于旺盛，反射率趋于减小；灌溉大豆田的反射率（０．１９）比无灌溉大豆田的（０．２１）略小；谷田和稻田的反射率分别为０．２１和０．１９。白天的热量平衡中，绝大部分净辐射用于潜热交换；夜里的热量平衡中，净辐射主要由潜热交换补给。随着小麦的生长，净辐射与太阳辐射的比值增大；灌溉大豆田净辐射与净辐射的比值高于无  相似文献