检索结果-南通市图书馆

Seismotectonics in the Pamir:An oblique transpressional shear and south-directed deep-subduction model

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2011年第1期2卷 1-15页

作者： Jiasheng Zhang Xinjian Shan xiongnan huang Institute of Geology China Earthquake Administration Beijing 100029 China

The 3-D geometry of the seismicity in Hindu Kush-Pamir--western China region has been defined by seismic records for 1975-1999 from the National Earthquake Information Center, the U.S. Geological Survey, and over 16,000 relocated earthquakes since 1975 recorded by the Xinjiang seismic network of China. The results show that most Ms≥ 5.0 hypocenters in the area are confined to a major intracontinental seismic shear zone （MSSZ）. The MSSZ, which dips southwards in Pamir has a north- dipping counterpart in the Hindu Kush to the west; the two tectonic realms are separated by the sinistral Chaman transform fault of the India-Asia collisional zone. We demonstrate that the MSSZ constitutes the upper boundary of a south-dipping, actively subducting Pamir continental plate. Three seismic concentrations are recognized just above the Pamir MSSZ at depths between 45-65 km, 95-120 km, and 180-220 km, suggesting different structural relationships where each occurs. Results from focal mechanism solutions in all three seismological concentrations show orientations of the principal maximum stress to be nearly horizontal in an NNW-SSE direction. The south-dipping Pamir subduction slab is wedge-shaped with a wide upper top and a narrow deeper bottom; the slab has a gentle angle of dip in the upper part and steeper dips in the lower part below an elbow depth of ca. 80--120 km. Most of the deformation related to the earthquakes occurs within the hanging wall of the subducting Pamir slab. Published geologic data and repeated GPS measurements in the Pamir document a broad supra-subduc- tion, upper crustal zone of evolving antithetic （i.e. north-dipping） back-thrusts that contribute to northsouth crustal shortening and are responsible for exhumation of some ultrahigh-pressure rocks formed during earlier Tethyan plate convergence. An alternating occurrence in activity of Pamir and Chaman seismic zones indicates that there is interaction between strike-slip movement of the Chaman transform fa

关键词： Earthquake Seismotectonics Deep-subduction ofcontinental crust Transform fault Ramp thrusting Central Asia

Earthquake fault framework and seismotectonics of the Songpan-Garze region since 1900

在线全文

学校读者我要写书评

暂无评论

Earthquake Science 2012年第5期25卷 451-458页

作者： Jiasheng Zhang Weijun Gan Minghua Zhang xiongnan huang Feng Liu Institute of Geology China Earthquake Administration Development Research Center of China Geological Survey

Based on 4 781 observed faults （〉2 km length） from a 1：200 000 scale digital geologic map and 5 220 recorded seismic events since the year 1900, 993 earthquake faults are identified within the triangular Songpan-Garze study region. The study area is delineated by the nearly EW-trending East Kunlun fault zone to the north, the NW-trending Xianshuihe fault to the south and the NE-trending Longmenshan thrust belt to the east. Seismicity changes along these earthquake faults, spanning four 10-year intervals since 1970, show that following a strong earthquake swarm, which occurred in the Huya area in the mid-1970s, seismic activity increased from north to south, and migrated eastward along each major strike-slip fault zone. GPS observation data before 2008 indicate a displacement rate across the Xianshuihe fault zone to the south of -6.5- 8.6 mm/a, whereas across the East Kunlun fault zone to the north it was -1.8- 2.2 mm/a. The May 12, 2008 Ms8.0 Wenchuan earthquake, which occurred in the southeast corner of the study region, was the result of stable, high-speed left-lateral displacement along the Xianshuihe fault zone, and a sharp eastward bend of the fault trend in response to the presence of crystalline rocks in the Kangding area. Therefore, the 110-year established seismotectonic framework of the Songpan-Garze region can be defined by a network of various earthquake faults and the structural relations of the local earthquake activities.

关键词： Songpan-Garze region earthquake fault GPS Wenchuan earthquake

Research on the Relationship between Active Faults and Earthquakes in the Junction Area of the China North-South Seismic Belt and Central Orogenic Belt Based on GIS

在线全文

学校读者我要写书评

暂无评论

Earthquake Research in China 2010年第4期24卷 432-444页

作者： Liu Feng Zhang Jiasheng huang xiongnan Niu Xianglong Institute of Geology China Earthquake Administration Beijing 100029 China

Research on the relationship between faults and seismicity in the junction area of China's north-south seismic belt and central orogenic belt based on the Geography Information System (GIS) has been *** each of the 16 faults in this area,we build a 25km buffer zone and use overlay analysis to investigate the seismicity and its characteristics on each *** results unveil the main seismic faults as follows:the western segment of the northern-edge of the west Qinling fault,the southwestern segment of the Lixian-Luojiabao fault,the southeastern segment of the Lintan-Dangchang fault,the southwestern segment of the Wenxian fault,the Huya fault,and the Xueshan *** most active faults are the Huya and Xueshan faults,then the Tazang fault,the Lixian-Luojiabao fault and the northern piedmont of the Guanggaishan-Dieshan *** research zone can be divided into four areas according to focal depth,which gets deeper from north to *** profile of focal depth indicates the geometry and mechanical property of faults,and further reveals the movement model of eastward extrusion of the Tibetan plateau and southeastward escape of masses,thus providing basis for the protection against earthquakes and hazard mitigation in this area.

关键词： Active fault Buffer analysis Spatial overlay analysis Seismicity Geography Information System (GIS)

中国北部古元古代地壳尺度的伸展拆离和硅铝壳内活动带:北东向线性航磁异常的地质构造解释

在线全文

学校读者我要写书评

暂无评论

地质科学 2007年第2期42卷 267-302页

作者：张家声李燕黄雄南中国地震局地质研究所北京100029 中国石油勘探开发研究院北京100083

早前寒武纪地质构造和分辨率大于120km的长波航磁异常特征表明：塔南-华北-朝鲜北部（狼林地块）具有类似的太古宙结晶基底，它们可能曾经是太古宙统一克拉通的组成部分。20～120km分辨率的中波航磁异常凸现一组北东东-北北东走向、改... 详细信息

早前寒武纪地质构造和分辨率大于120km的长波航磁异常特征表明：塔南-华北-朝鲜北部（狼林地块）具有类似的太古宙结晶基底，它们可能曾经是太古宙统一克拉通的组成部分。20～120km分辨率的中波航磁异常凸现一组北东东-北北东走向、改造太古宙高级变质结晶基底的线性航磁异常，它们分别对应于地壳尺度的长寿断裂。古元古代阶段沿着它们发生了大规模的左行韧性伸展剪切运动，在使塔南、朝鲜北部陆块分别向南西和北东伸展拆离的同时，华北克拉通内部也出现了有限的裂解，并伴随着硅铝壳内活动带的发育。本文将这些古元古代阶段韧性伸展剪切带划分为塔南与华北陆块之间的西部剪切带系统、华北与狼林陆块之间的东部剪切带系统和华北陆块内部的青龙-太行山-中条山等3个独立的剪切带系统。西部韧性剪切系统由阿尔金、大同-环县、以及它们之间的狼山-吉兰泰、雅布赖山等次级剪切带组成，控制古元古代阿拉善群和上集宁群的孔兹岩系为代表的硅铝壳内活动带的沉积-构造演化。东部韧性剪切系统包括沂水和新宾-桦甸等韧性剪切带，相关的古元古代活动带以胶东地区的粉子山群、荆山群和辽吉地区的辽河群为代表。中部韧性剪切带系统以太行山地区阜平群、赞皇群中出现的角闪岩相糜棱片麻岩、眼球状糜棱岩带为代表，发育b-型线理，指示近水平或低角度斜滑性质的左行韧性剪切，相关的古元古代活动带包括双山子-青龙河、五台-滹沱、甘陶河-东焦、吕梁、中条以及济宁等。不同规模的古元古代活动带彼此并不相连，以发育变质沉积-火山岩建造为主体，岩石磁化率明显低于太古宙高级变质结晶基底，与之相关的韧性剪切带则以其透入性矿物线理产生了增强的磁化率各向异性，两者共同构建了地壳尺度北东东-北北东向线性航磁异常带。古元古代末的中条运动使上述硅铝壳内活动带褶皱回返，塔南-华北-朝鲜北部陆块重新焊接，形成近纬向展布逐渐稳定的中轴大陆克拉通，上述地壳尺度的韧性伸展剪切带在中元古代以后的地质历史中，大多被后期不同性质的脆性断裂所追踪。

关键词：伸展剪切硅铝壳内活动带航磁异常线理古元古代中国北部

华北陆块基底构造格局及早期大陆克拉通化过程

在线全文

学校读者我要写书评

暂无评论

岩石学报 2000年第1期16卷 1-10页

作者：李江海钱祥麟黄雄南刘树文北京大学地质学系北京100871

依据区域构造分析及同位素年代学数据库 ,华北克拉通变质基底主要可以区划为以下构造单元 :1)鄂尔多斯陆块新太古代被动边缘沉积 ;2 )恒山 -承德太古代末期构造带 ;3)太古代末期五台 -登封岛弧带杂岩及构造缝合带 ;4)鲁西 -冀东 -辽吉... 详细信息

依据区域构造分析及同位素年代学数据库 ,华北克拉通变质基底主要可以区划为以下构造单元 :1)鄂尔多斯陆块新太古代被动边缘沉积 ;2 )恒山 -承德太古代末期构造带 ;3)太古代末期五台 -登封岛弧带杂岩及构造缝合带 ;4)鲁西 -冀东 -辽吉新太古代活动大陆边缘岩浆杂岩带 ;5 )胶辽陆块 ;6 )冀北 -固阳古元古代初造山带及内蒙 -冀东再造麻粒岩相带 ;7)吕梁 -中条古元古代裂谷带 ;8)辽南古元古代裂谷带。华北克拉通早期构造演化历史主要涉及东部陆块西缘的岛弧增生及其与西部陆块的碰撞拼合 ,太古代末期克拉通北缘开始形成增生型陆缘活动带 ,并造成克拉通中部的裂谷作用。东部古郯庐断裂带的活动造成辽南 -鲁北古元古代裂谷带的形成。最后 ,以古元古代末期的拗拉谷系、基性岩墙群为标志的伸展构造体制。

关键词：杂岩表壳岩系板块构造华北陆块基底构造格局

Microscopic deformation of the Neoarchean oceanic lithospheric mantle: evidence from the Zunhua Neoarchean ophiolitic mélange,North China Craton

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2003年第8期 49-56+87页

作者： huang xiongnan , LI Jianghai, NIU Xianglong and FENG Jun(The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China) TheKeyLaboratoryofOrogenicBeltsandCrustalEvolution SchoolofEarthandSpaceSciencesPekingUniversityBeijing100871China

The microstructures of the mantle tectonites in the Zunhua Neoarchean ophiolitic mlange are mainly coarse-mosaicstructures with locally interstitial impregnated melts. Olivine and orthopyroxene occur as residual porphyroclastic blasts, dynamic recrys-tallization neoblasts or elongated to be tabular. The podiform chromitites are mostly strongly deformed with the development of pull-apartstructure. These microstructures are typical high-temperature plastic deformation in oceanic upper mantle resulting from ocean-floorspreading. Besides the high-temperature plastic deformation, undeformed magmatic intrusions such as undeformed podiform chromitite,dunite and pyroxenite intrusions are also preserved in the mantle tectonite. Structures of high-temperature plastic deformation and intensivemagmatic activity prove that the Zunhua ophiolite was formed under fast spreading oceanic ridge, similar to the Oman ophiolite. And themicrostructures of country rocks, such as quartz ribbon, core and mantle structure, dynami

关键词： Neoarchean ophiolitic melange microstructures oceanic upper-mantle structural deformation.

帕米尔地区现今大陆深俯冲——地震构造和动力学解释

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

岩石学报 2005年第4期21卷 1215-1227页

作者：张家声单新建李建华黄雄南中国地震局地质研究所北京100029

在 NEIC(UsGS)1975～1999年地震记录的基础上,补充中国新疆地震台网1975年以来的16,339个部分重新定位的有效地震记录,根据该地区地震活动时空分布规律、地壳速度结构和地表变形构造等最新研究成果,对兴都库什-帕米尔-中国西部地震活动... 详细信息

在 NEIC(UsGS)1975～1999年地震记录的基础上,补充中国新疆地震台网1975年以来的16,339个部分重新定位的有效地震记录,根据该地区地震活动时空分布规律、地壳速度结构和地表变形构造等最新研究成果,对兴都库什-帕米尔-中国西部地震活动的三维几何学及其构造联系作出了新的解释,强调沿恰曼断层的左行走滑作用对帕米尔和兴都库什地震带的制约。沿帕米尔地震带正在发生大陆深俯冲作用,是恰曼断层左行牵引的结果,深俯冲岩板为上宽下窄向恰曼断层收敛的楔形体,俯冲角度上缓(20～30°)下陡(60～70°),转变深度在80～120公里,部分下地壳物质被深俯冲作用带到200公里以下的深度。帕米尔深俯冲带上盘岩石中的多期反冲构造组合和后退俯冲作用历史,解释了该地区地壳缩短加厚和深部岩石折返的机制。与深俯冲作用相关的双地震剪切带和3个地震群的构造联系,提供了大陆深俯冲作用的动力学信息。

关键词：地震地震构造大陆深俯冲转换断层反冲断层作用

遵化新太古代豆荚状铬铁矿变形特征、变形机制及其大洋地幔扩张运移的指示意义

在线全文

学校读者我要写书评

暂无评论

大地构造与成矿学 2006年第2期30卷 149-160页

作者：陈征李江海程素华黄雄南造山带与地壳演化教育部重点实验室北京大学地球与空间科学学院北京100871

豆荚状铬铁矿是蛇绿岩套地幔构造岩中特征的矿产,其矿石发育丰富的岩浆活动-高温变形结构构造类型,豆荚状铬铁矿高温下仍具有稳定的物理化学特性,对认识大洋上地幔扩张、横向运移具有重要指示意义。在对遵化新太古代豆荚状铬铁矿显微构... 详细信息

豆荚状铬铁矿是蛇绿岩套地幔构造岩中特征的矿产,其矿石发育丰富的岩浆活动-高温变形结构构造类型,豆荚状铬铁矿高温下仍具有稳定的物理化学特性,对认识大洋上地幔扩张、横向运移具有重要指示意义。在对遵化新太古代豆荚状铬铁矿显微构造的深入研究基础上,通过对比分析豆荚状铬铁矿结构构造特征(岩浆活动、低温变形),提出高温变形结构及其特征(拉长网孔结构、条带状、糜棱状结构等)。借鉴现代洋中脊及弧后盆地扩张的构造模型,提出华北新太古代豆荚状铬铁矿扩张中心形成后的显微构造演化序列,豆荚状铬铁矿变形机制的研究,可以提供认识早期大洋上地幔动力学过程的新线索。

关键词：豆荚状铬铁矿高温变形大洋上地幔板块构造早期演化

在线全文

学校读者我要写书评

暂无评论

遵化豆荚状铬铁矿岩浆流变学性质

地球学报 2006年第4期27卷 310-314页

作者：陈征李江海程素华黄雄南北京大学地球与空间科学学院地质学系北京100871

对遵化豆荚状铬铁矿中250个铬铁矿豆体的形态、大小、向椭球体转变的程度等统计分析表明,豆体在上升期间与岩浆作用的过程中伴有由等轴体(近似为球体)向椭球体转变的过程。其主要原因是豆体在相对岩浆运动的过程中,豆体的表面与岩浆之... 详细信息

对遵化豆荚状铬铁矿中250个铬铁矿豆体的形态、大小、向椭球体转变的程度等统计分析表明,豆体在上升期间与岩浆作用的过程中伴有由等轴体(近似为球体)向椭球体转变的过程。其主要原因是豆体在相对岩浆运动的过程中,豆体的表面与岩浆之间的粘滞摩擦造成的。粘滞摩擦力的大小、作用于豆体表面的时间又取决于岩浆的粘度、豆体相对于岩浆的沉降速度、豆体半径的大小及岩浆上升的速度,所以这些因素将决定豆体变形(磨蚀、椭球化)的程度。因此,可用豆体与岩浆相互作用的物理过程来模拟豆体的变形特点,而反过来据实测的豆体变形程度数据又可推算岩浆真实的上升速度。

关键词：豆荚状铬铁矿流变学性质大洋扩张遵化