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1.
华北新构造：印欧碰撞远场效应与太平洋俯冲地幔上涌之间的相互作用 总被引：1，自引：0，他引：1
作为大陆内部典型的伸展断陷区和强震活动区,华北地区处于东部太平洋板块俯冲构造和西部印欧大陆碰撞构造的双重大地构造背景之下,其新构造运动相当复杂:西部沿鄂尔多斯地块周缘两个地堑盆地系引张伸展断陷作用、中部太行山块体的局部断陷和整体隆升、东部华北平原区和渤海湾海域区的区域沉降,南缘沿秦岭构造带的左旋走滑拉张活动,东缘沿郯庐断裂带的右旋挤压走滑活动。这些不同类型的断裂构造在晚新生代的阶段性活动,产生了复杂的构造地貌组合特征。综合研究发现,华北晚新生代经历了3期伸展断陷-挤压隆升演化阶段:新近纪晚期(10～2.5 Ma)、早中更新世和晚更新世以来。地壳引张应力方向或NW-SE、或NE-SW向;地块隆升导致湖盆的消亡,挤压应力方向为NE-SW至W-E向。研究认为,华北地区新构造受两个岩石圈构造过程的相互影响:印欧碰撞产生的远程效应和东部岩石圈地幔的上涌。一方面,青藏高原东北缘地块的持续推挤及其构造应力向东的传递导致鄂尔多斯地块反时针旋转和秦岭山地的向东挤出逃逸,这个挤出构造动力学统治了华北地区晚新生代的引张伸展、斜张走滑和挤压变形。尤其是,新近纪晚期强烈的NW-SE向地壳伸展变形与青藏东缘挤出造山作用同步(10～9 Ma至4.2 Ma);上新世末期(约2.5 Ma)、晚更新世早期(约200～70 ka)和晚更新世晚期—全新世(约20 ka以来)3次构造挤压事件与青藏高原东缘构造事件基本对应。另一方面,岩石圈地幔上涌主导了华北东部平原区的区域地壳沉降,同时伴随着早、中更新世的5期幔源火山活动。这两个岩石圈构造作用力此消彼长,深刻统治着华北地区新构造与现今活动构造以及地震构造。 相似文献
2.
华北克拉通破坏区是历史破坏性地震频发区,震源机制解和地震地表破裂带等反映出历史地震的发震断层为新生走滑断层,很难用地壳的伸展构造系统来合理解释.首先对1679年三河-平谷M8.0级地震的大厂隐伏凹陷西边界夏垫断裂进行高分辨率地震勘探和上盘钻孔地层进行标定,然后在河套断陷盆地带大青山南麓晚更新世湖相地层中识别出2期角度不整合面(UC1和UC2),并进行了系统测年,综合近年来活动断层比例尺填图和城市活动断层探测成果,明确指出,在华北克拉通破坏区,代表新生代早期地壳伸展运动的铲形正断层的活动性在上新世至第四纪早期逐渐减弱,到晚更新世早期基本停止活动;晚更新世中期以来大青山构造运动为华北克拉通破坏区最新一期构造运动,主要表现为区域剪切应变条件下新生走滑断层形成和扩展,并伴随相关地震活动.最新构造运动的主要动力来源于青藏高原物质东向挤出,以及其对鄂尔多斯块体西南缘强烈东向推挤作用.这些新认识对深化华北克拉通破坏区地震发震机理研究,理解板内最新变形动力学,均具有十分重要的科学价值. 相似文献
3.
ZHANG Yueqiao Institute of Geomechanics Chinese Academy of Geology Beijing ChinaPierre Vergely Jacques-Louis Mercier URA-CNRS: Geophysique et Geodynamique Interne Universite de Parie-Su Bdtment F- Orsay-Cedex France WANG Yongmin ZHANG Yong HUANG DezhiInstitute of Geology Bureau of Geology Mineral Resouces of Anhui Province Hefei China 《《地质学报》英文版》1999,73(3):264-274
Since the mid-late Eocene, North China has been subjected to extensional stress, resulting in the formation and development of basins. The dynamic origin of this crustal extension has long been an issue of debate. This paper presents the results of kinematic analyses of faults obtained from two seperated areas in North China. In the Weihe graben situated on the southernmost margin of the Ordos block, analyses of fault kinematics were coupled with an analysis of the basin's subsidence history. Three successive extensional tectonic phases accompaning the basin's formation and development have been distinguished. The Palaeogene extension was oriented in a WNW-ESE direction; the Neogene extension in a NE-SW direction and the Pliocene-Quaternary extension in a NW-SE direction. Such changes have also been recorded by fault kinematics along the southern Tanlu fault zone. This has been demonstrated by three successive sets of fault striations indicating normal dip slip resulting from NW-SE extension, then left- 相似文献
4.
羌塘盆地托纳木地区新生代发育规模较大的洞错地堑构造,走向近南北,长度大于80km,由断隆带和断陷盆地组成,并对研究区地貌和水系格局有明显的控制作用。地堑活动始于中新世,现今仍处于活动之中,其形成可能受深部热动力学机制作用制约。沿地堑正断层存在明显的油气异常,对油气藏具有显著的破坏作用,不利于油气的保存。 相似文献
5.
中国东部NWW向活动断裂带构造特征:以张家口-蓬莱断裂带为例 总被引：7，自引：0，他引：7
中国东部新构造期活动强烈,前人对该时期NE向构造已有很多研究,但NWW向构造研究程度较低.本文以张家口-蓬莱断裂带为例,从几何学、运动学、动力学及地震活动性四个方面对中国东部的NWW向活动断裂带进行了分析.结果表明,中国东部的NWW向活动断裂带具有左行走滑的运动性质,并控制了第四纪盆地左阶雁列的展布样式;NWW向活动断裂带是孕震断裂,诱发了多次地震活动.在动力学上,这些断裂带是扳缘的不同段落变形在板内不同块体间响应调节的产物,且在周边板块的联合作用下,华北和华南南部NWW向断裂可能印度-欧亚板块碰撞的影响占主导,而东北和华南东部NWW向断裂可能太平洋板块俯冲的影响占主导. 相似文献
6.
从遥感地质角度，结合地质、地貌来研究东北地区新生代地壳水平运动特征、规律。东北新生代地壳水平运动表现为水系变形、山体错移、新构造被错断、地质体错移变形等。呈现出其运动的广泛性、协调性、多期性、继承性和持续性。该区的应力场在新生代期间多次改变，并控制了主要断裂的活动方式。 相似文献
7.
《International Geology Review》2012,54(5):537-554
The Bohai Bay Basin is a Cenozoic extensional basin along the eastern aspect of Asia. Whether the Bohai Bay Basin is a pull-apart or rift basin is controversial. The Bohai Bay Basin exhibits a high density of extensional faults and records destruction of the North China Craton. Many structural analyses have been performed on the Bohai Bay Basin, especially the Tan-L and Taihang Mountain fault systems which control its boundary. The initial deposition of Kongdian Formation was mainly distributed along the boundary of Bohai Bay Basin during the Palaeocene–early Eocene. Subsequently, tectonic activity migrated toward the interior of the basin during deposition of Shahejie Formation in the middle Eocene–early Oligocene. Bohai Bay Basin crust was thickened in early Mesozoic time and has thinned since late Mesozoic time. The crustal strength profile of Bohai Bay Basin is characterized by very weak lower crust, which differs from that of adjacent crust. In regard to the crustal structure, lithospheric thickness, and extensional style, an alternative rift model is proposed. Initial Bohai Bay Basin rifts were characterized by metamorphic core complexes affecting the North China Craton, which reflects collapse of parts of the early Mesozoic intra-plate orogen. Furthermore, westward subduction of the Palaeo-Pacific Plate led to upwelling of asthenosphere mantle. Persistent upwelling of mantle decreased the strength of lower crust and led to the warm heat-flow regime and generation of a lower crustal fluid layer and wide rifting. Outward flow of ductile lower crust following late Cretaceous extension thinned the lower crust and generated the overall sag appearance of the basin in early Cenozoic time. The model supports a model whereby a wide rift narrows with time. For the Bohai Bay Basin, extension and strike-slip faulting were two independent deformation systems superimposed on each other. 相似文献
8.
南海北部活动构造及其对天然气水合物的影响 总被引：1，自引：0，他引：1
海底天然气水合物与活动构造关系极为密切,随着近十几年来海底天然气水合物勘探与研究取得的重要进展,相关活动构造也正在逐渐受到关注。通过对断裂、地震、气底辟以及海底火山活动等构造活动的多种表现形式的研究,分析了南海北部活动构造的特征。在南海北部,存在北东向、北东东-东西向、北西向3组活动断裂,其中北西向断裂切割其他两组,形成最晚。这些活动断裂以继承性为主,北东向和北东东向断裂均为切割地壳或岩石圈的大断裂。南海北部的震中呈带状分布,在东部呈北东走向,而西部受红河走滑断裂的影响,震中整体为北西走向分布。气底辟是对天然气水合物形成有重要指示意义的构造,同断裂一样,气底辟为气源垂直向上移动至形成水合物的温压带提供了良好的通道。南海北部分布的火山岩由东到西顺时针旋转。从地震剖面可以看出,岩体明显受张性断裂控制。东部天然气水合物的分布受北西向活动断层的影响较大,而西部则与海底滑坡密不可分。 相似文献
9.
地壳的拆离作用与华北克拉通破坏:晚中生代伸展构造约束 总被引：19，自引：0，他引：19
伸展条件下的地壳拆离作用是岩石圈减薄的重要浅部构造响应。晚中生代时期的伸展构造(包括拆离断层、变质核杂岩构造和断陷盆地)在华北、华南、东北和东蒙古及贝加尔地区普遍发育,它们切过上部地壳(断陷盆地)、中、上地壳(拆离断层)或中部地壳(变质核杂岩)。地壳拆离作用具有运动学极性(NWW或SEE)、几何学宏观(区域)对称与微观(局部)不对称性、遍布全区但不均匀性,以及形成时间的跨越性(140~60Ma)等特点,并使得地壳和岩石圈发生显著的减薄。本文研究揭示出现今岩石圈厚度变化与晚中生代伸展构造的发育程度和分布之间并没有必然的联系。其变化的基本规律是,除新生代裂陷发育区岩石圈厚度明显较小且厚度有迅速变化外,从华北向贝加尔地区总体的变化趋势是逐渐加厚,也即东亚地区岩石圈具有楔形形态。晚中生代时期的地壳(或地幔)拆离作用伴随着广泛的岩石圈减薄作用,区域岩石圈同时遭受到一定程度的减薄和破坏,华北克拉通在这一时期的破坏仅仅是区域岩石圈减薄在华北的具体体现。 相似文献
10.
南海的形成演化受控于印-澳、欧亚以及太平洋板块的相互运动,为研究汇聚背景下板块碰撞及其远程效应提供重要窗口。为了揭示该汇聚背景下的多幕裂陷过程,本文选取地质信息丰富的整个珠江口盆地为典型区,利用三条高精度地震剖面,对盆地各地质单元进行断层活动速率和构造沉降速率的定量计算及综合分析。结果表明盆地裂陷期东部、中部和西部主要控凹断层的平均活动速率分别为96 m/Ma、223 m/Ma和124 m/Ma,且其平均沉降速率依次为8.5 m/Ma、34 m/Ma和12.7 m/Ma,盆地整体呈现中部裂陷作用最强,其后向西部和东部逐渐减弱的特征。本文认为这与先存断裂以及初始地壳厚度有关:盆地东部和中部存在NE向先存断裂,并且东部先存断裂更加活跃,因此在新生代拉伸应力下东部更易表现为裂陷作用最强的区域,其次为中部和西部;而受前新生代时期俯冲作用的影响,岩浆的底垫作用引起盆地东部地壳增厚,东部裂陷作用强度急剧降低,造成裂陷作用强度的东西差异。此外,盆地南段凹陷裂陷期的断层活动和沉降速率发生激增,裂陷作用存在向南迁移的现象。本文推测在深度相关的伸展模式的影响下,南段凹陷地壳温度升高,强度减弱,因而在伸展应力下发生快速的拉伸减薄,导致裂陷中心向南迁移及岩浆物质上涌。同时,侵入的岩浆物质导致高角度正断层转换成低角度正断层,进一步促进裂陷中心向南迁移。 相似文献
11.
<正> 近年来在我国获得大量的地质、地球物理和地球化学等资料的基础上,特别是将地表地质构造的研究与深部地质构造和新构造运动的研究结合起来,更加深和丰富了对大地构造的认识。 1957年,地质部航测大队首次在我国东部发现了郯城—庐江深大断裂带。同时,大量的地球物理工作,为我国早期油田的勘探与开发提供了地质构造的依据。六十至七十年代,利用人工地震研究地壳和上地幔的结构,提出了部分地区的详细地壳模型和地壳厚度。在我国某些地区开始了古地磁学的研究。 相似文献
12.
Martha Withjack 《Tectonophysics》1979,53(1-2)
Two proposed mechanisms of rift initiation are crustal uplift alone and a combination of crustal uplift and regional horizontal extension. A three-dimensional, thick-plate, elastic analysis has been used to model the crustal stress state and the fault patterns associated with these mechanisms. Small ratios of uplift width to crustal thickness (<10) necessitate the thick-plate approach.For the crustal uplift model, the surface fault pattern is characterized by normal faults trending parallel to the major uplift axis at the uplift center and radial normal faults toward the ends of the major uplift axis. Zones of compressional structures (e.g., strikeslip and thrust faults) may develop at the periphery of the uplift. Superposition of regional horizontal tension with the stresses produced by crustal uplift eliminates the compressive stresses at the uplift periphery producing normal faults parallel to the major uplift axis at the uplift center and normal faults perpendicular to the major uplift axis at the uplift periphery.A comparison of these predicted fault patterns with the faults of the Rhine graben suggests that the combination of crustal uplift and regional horizontal extension contributed to the formation of that rift system. The stresses produced by crustal uplift promoted the formation of the central graben and the fan-shaped troughs toward the ends of the major uplift axes, while superposed regional horizontal tension eliminated the large compressive stresses at the uplift periphery promoting the normal faulting and dike intrusions observed on the Rhine graben flanks. 相似文献
13.
李绍柄 《吉林大学学报(地球科学版)》1990,(2)
地壳表层构造和深部构造互相制约是控制河北地区许多强震发生的必要地质条件。由此地质条件,在水平与垂直两个相互叠加的应力场作用下,使河北地区发生许多强震。这个构造-应力场模式,对华北地区许多强震的发生可能具有普遍意义。 相似文献
14.
A revised assessment of architecture and pre-rift fabric connections of the Oslo Rift has been undertaken and linked to a new appraisal of observations and data related to the initial phase of the rift evolution. In addition to half-graben segmentation, accommodation zones and transfer faults are readily identified in the linking sectors between the two main grabens and between graben segments. Axial flexures are proposed between facing half-grabens. The accommodation zones were generally sites of volcanism during rifting. Pre-rift tectonic structures played an influential role in the rift location and development. The deviant N-S axis of the Vestfold graben segment is viewed as related to pre-rift structural control through faults and shear zones. This area was probably a site of Proterozoic/Palaeozoic crustal and lithospheric attenuation.
Field evidence suggests that the rift started as a crustal sag with no apparent surface faulting in a flat and low-lying land at a time about 305–310 Ma. Volcanism, sub-surface sill intrusion and faulting started about simultaneously some time after the initial sag (300–305 Ma). Faulting and basaltic volcanism were initially localized to transfer faults along accommodation zones and a NNW-SSE transtensional zone along the eastern margin of the incipient Vestfold graben segment. This transtensional zone was probably created by right-lateral simple shear tracing pre-rift structures in response to a regional stress field with the tensional axis normal and the maximum compressional axis parallel to the NNE-SSW-trending rift axis. 相似文献
15.
Prof. Dr. Henning Illies 《International Journal of Earth Sciences》1970,59(2):528-552
A system of intracontinental grabens extends over Western Europe, the Levant and East Africa. Small crustal segments framed by elevated shoulders are sunken along parallel escarpments and disintegrated by antithetic normal faults. The shoulders are risen up as outward tilted blocks and thought to form a closed vault at the base of the crust, corresponding to the wedge block of the graben. Underneath the Rhinegraben exists, as detected by seismic refraction measurements, a pillow-shaped body of material with P-wave velocities of 7.4 to 7.9 km/sec, intercalated between crust and mantle. The taphrogenesis of all larger grabens is assumed to be induced by the formation and growth of subcrustal swells of this type. Also the specific graben volcanism is thought to be connected with the intruded laccolithic body of mantle-derived material. The tensional breakup and the faulting of the warped crustal masses was favoured by the gravity slide of the crust which was uncoupled from the substratum by the intercalated magmatic layer. Along the Red Sea Rift the crust tore completely releasing the basaltic substratum in the inner graben. The pattern of its magnetic anomalies leads to the assumption that the pillow body is recruited by simatic dike injections according to the principle of sea-floor spreading. Therefore, there is a great conformity between the intercontinental and the mid-oceanic rift systems. The supplies of mantle material along the Mid-Atlantic and the Carlsberg Rift are related to the drift of the continental frames. The mid-oceanic rift systems in their medial position to the framing continental margins correspond to the intracontinental graben swarm, equidistant from both fronts of circum-Pacific tectonics. A reciprocating action is presumed between the ascending masses along the rift zones and the suction of masses along the deep-sea trenches and geosynclines. The observed crustal movements imply an equilibrant plastic flow within the upper mantle, probably impelled by mechanical convection currents. The continental unbalance between the Pacific and the anti-Pacific hemisphere is discussed as causing mantle currents. Within this interplay between crust and mantle and between continents and ocean floors, the oceanic crust had obtained harmonical features moulded directly by the deduced mobility. The continental crust, however, is passively stressed, its rocks are affected by heterogeneous deformations from which the continents got its polygenetic multiform fabric. 相似文献
16.
Tectonic Environments of Cenozoic Volcanic Rocks in China and Characteristics of the Source Regions in the Mantle 总被引：1，自引：0，他引：1
Extensive volcanism is one of the important features of Cenozoic geology in China.Based on temporal-spatial distribution,the volcanism was associated with three major different geological settings:1)the continental rift basalts in Northeast and North China;2)the tension-fault basalts on the continental margins of Southeast China; and 3) the collision-zone high-K volcanics in the Qinghai-Xizang Plateau and its vicinities.The characteristics of “depletion in the south and enrichment in the north“of the China continental mantle are strongly supported by isotopic evidence.The Cenozoic continental cal characters,into the following geochemical provinces:1)the depleted mantle in South China;2)the primary mantle in Northeast and NorthChina; 3)the hybrid and transi-tional mantle in the region of Shandong ,Anhui,Jiangsu and northern Zhejiang;4)the depleted mantle around the Bohai Bay and the Lower Liaohe River;5)the K-metasomatic enriched mantle in the northern part of Northeast China;and 6)the re-cycled enriched mantle in the ancient subduction zone in the Qinghai-Xizang Plateau and its surround-ings.These geochemical characteristics on a regional scale must be a reflection of the nature of lithosphere evolution. 相似文献
17.
大陆玄武岩通常具有与洋岛玄武岩相似的地球化学成分,其中含有显著的壳源组分.对于洋岛玄武岩来说,虽然其中的壳源组分归咎于深俯冲大洋板片的再循环,但是对板片俯冲过程中的壳幔相互作用缺乏研究.对于大陆玄武岩来说,由于其形成与特定大洋板片在大陆边缘之下的俯冲有关,可以用来确定古大洋板片俯冲的地壳物质再循环.本文总结了我们对中国东部新生代玄武岩所进行的一系列地球化学研究,结果记录了古太平洋板片俯冲析出流体对地幔楔的化学交代作用.这些大陆玄武岩普遍具有与洋岛玄武岩类似的地球化学成分,在微量元素组成上表现为富集LILE和LREE、亏损HREE,但是不亏损HFSE的分布特点,在放射成因同位素组成上表现为亏损至弱富集的Sr-Nd同位素组成.在排除地壳混染效应之后,这些玄武岩的地球化学特征可以由其地幔源区中壳源组分的性质来解释.俯冲大洋地壳部分熔融产生的熔体提供了地幔源区中的壳源组分,其中包括洋壳镁铁质火成岩、海底沉积物和大陆下地壳三种组分.华北和华南新生代大陆玄武岩在Pb同位素组成上存在显著差异,反映它们地幔源区中的壳源组分有所区别.中国东部新生代玄武岩的地幔源区是古太平洋板片于中生代俯冲至亚欧大陆东部之下时,在>200 km的俯冲带深度发生壳幔相互作用的产物.在新生代期间,随着俯冲太平洋板片的回卷引起的中国东部大陆岩石圈拉张和软流圈地幔上涌,那些交代成因的地幔源区发生部分熔融,形成了现今所见的新生代玄武岩. 相似文献
18.
The Crustal Structure and Seismic Activity in North China 总被引：1，自引：0，他引：1
Feng Rui Huang Guifang Zheng Shuzhen Wang Jun Yan Huifen Zhang Ruoshui 《《地质学报》英文版》1989,63(4):343-359
A layered crustal block model of North China has been constructed based on large amount of data from seismic sounding carried out in recent two decades. Some deep fault zones, such as the Zhangjiakou.Penglai and Tancheng-Lujiang fault zones, divide the upper crust of North China into three upper crustal terranes and nine bolcks. There are distinct differences in velocity and depth distributions, which reflects Cenozoic block faulting in North China in the process of formation of the deep structure. The upper crust shows the features of transition in isostatic adjustment. The existence of a low-velocity layer in the middle crust is characteristic of the crustal structure in North China. There seems to be an increase of rheology of the rocks in the lower crust and a persistence of stable regional stress field. The patterns of the Moho on two sides of the Yanshan-Taihang Mountains are different. The relief of the Moho around Beijing, Shijiazhuang and Guangrao where the deep faults join together shows a quadrantal distribution in some degree. The dynamic sources for seismic activity are the NE-SW horizontal compression and the diapirism of the upper mantle. The middle and upper crust, especially the layered block structure has the most significant effects on seismicity, and the occurrence of earthquakes is more closely related to them than to the Moho. 相似文献
19.
要通过在TM遥感图像解译和野外观测的基础上,描述了东昆仑断裂带东段活动形迹的组成和活动断层地貌特征,阐述了甘南高原西秦岭地区新近纪拉分盆地的沉积-构造特征,提出了该区东昆仑-秦岭断裂系晚新生代左旋走滑伸展-走滑挤压-走滑伸展的3个阶段的构造变形模式。指出,中新世晚期至上新世早期,东昆仑-秦岭断裂系以左旋走滑伸展活动为主,伴随着西秦岭地区拉分盆地的形成和超基性火山岩群的发育。这期左旋走滑伸展活动向东扩展导致了渭河盆地新近纪引张应力方向由早期的NE-SW向转变为晚期的NW—SE向。上新世晚期以来(约3．4Ma以前),东昆仑-秦岭断裂系以左旋走滑挤压活动为主,导致早期拉分盆地的轻微褶皱变形,走滑挤压活动主要集中在东昆仑东段玛沁-玛曲主断裂带上。该期构造变动持续到早更新世,它的向东扩展产生了广泛的地壳形变效应,包括青藏东缘岷山隆起带的快速崛起、华北地区汾-渭地堑系的形成和发展以及郯庐断裂带右旋走滑活动等。中、晚更新世时期,断裂系以走滑伸展变形为主,主要集中在东昆仑断裂带东段3个分支上,地块向东挤出伴随着顺时针旋转。 相似文献
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为了探讨日本MW 9.0级大地震前后华北和东北地区现今构造应力作用调整过程与研究意义,对华北和东北地区进行原位现今地应力绝对测量与实时监测、GPS测量,结果表明：日本大地震在山东半岛、华北北部地区和东北地区所诱发同震位移引起的张性效应调整周期分别约为6个月(即调整结束时间大约在2011年9月)、15个月(即调整结束时间大约在2012年6月)和26个月(即调整结束时间大约在2013年5月),张性效应调整周期与同震位移大小成正比。在这种调整过程中,往往表现出区域现今构造应力作用方式和构造应力场转换,并可能伴随重大地质事件(如地震等)的发生。2012年5月28日和29日、6月18日、8月26日及2013年1月11日在唐山及其周围地区分别发生的4.8级、3.2级、4.0级、3.3级和3.0级地震与华北北部地区构造应力作用方式和构造应力场转换有关,而2013年10月31日以来在吉林省松原市发生的地震群应与东北地区构造应力作用方式和构造应力场转换有关,而非一个大地震前的小震群。 相似文献