川滇地区应力场演化与强震间相互作用的三维有限元模拟   总被引：9，自引：0，他引：9       下载免费PDF全文

陈化然  陈连旺  马宏生  李轶群  张杰卿  何巧云  王建国 《地震学报》2004,26(6):567-575

针对川滇地区，在大量搜集、总结前人资料和结果的基础上，建立了包括上地壳、下地壳(两层)、上地幔等4层结构的三维有限元模型. 通过反复调试，确定了其边界条件，并且计算了川滇地区背景应力场、断层蠕动产生的应力场和强震触发的应力场，以及它们的动态变化. 结果表明:后续地震大多发生在前面地震引发的库仑破裂应力正值区，前一地震对后续地震有一定的触发作用，强震是在较高的应力背景下成组发生的. 这对判断、识别地震异常，提高地震预测水平有着很大的意义.   相似文献   

1303年山西洪洞8级地震地表破裂带di   总被引：6，自引：0，他引：6       下载免费PDF全文

江娃利  邓起东  徐锡伟  谢新生 《地震学报》2004,26(4):355-362

综合20世纪90年代初在霍山山前断裂和近年在绵山西侧断裂和太谷断裂获取的最新调查资料，讨论了1303年山西洪洞8级地震地表破裂带的展布和位移特征. 如果太谷断裂、绵山西侧断裂与霍山山前断裂在1303年洪洞地震中同时活动，则该次地震的地表破裂带长163 km，分为3段，即霍山山前断裂段、绵山西侧断裂段和太谷断裂段. 各段长度分别为50，35和70 km，3段之间存在4和8 km的阶区. 该地震地表破裂带具右旋走滑特征，北段和中段右旋走滑位移量6～7 m，南段最大为10 m. 在山西断陷带盆地边界的单条断裂一般只对应7级地震，而该次8级特大地震则突破两个盆地之间的障碍体，显示了强震地表破裂尺度的可变特征.   相似文献   

Geochemistry of the ophiolite and oceanic island basalt in the Kangxian-Pipasi-Nanping tectonic melange zone, South Qinling and their tectonic significance     

LAI Shaocong  ZHANG Guowei  PEI Xianzhi & YANG HaifengKey Laboratory of Continental Dynamics  Ministry of Education  Department of Geology  Northwest University  Xi''''an  China Correspondence should be addressed to Lai Shaocong 《中国科学D辑(英文版)》2004,(2)

Detailed studies indicate that Kangxian-Pipasi-Nanping tectonic zone is a complicated melange zone which includes many tectonic slabs of different origins. Ophiolite (MORB-type basalt), oceanic island tholeiite and alkaline basalt have been identified. Moreover, this tectonic melange zone is eastward connected with the Mianlue suture zone. The deformation characteristics, consisting components and volcanic rock geochemical features for the Kangxian-Pipasi-Nanping tectonic melange zone are much similar to those of the Mianlue suture zone and Deerni ophiolite. Therefore, the Kangxian-Pipasi-Nanping tectonic melange zone should be the westward extension part of the Mianlue suture zone. It indicates that the Mianlue suture zone had extended to the Nanping area.  相似文献   

Geochemistry and regional distribution of ophiolites and associated volcanics in Mianle suture, Qinling-Dabie Mountains     

LAI Shaocong  ZHANG Guowei  DONG Yunpeng  PEI Xianzhi & CHEN Liang Key Laboratory of Continental Dynamics  Ministry of Education  Department of Geology  Northwest University  Xian  China 《中国科学D辑(英文版)》2004,(4)

The Mianl黣 tectonic zone has been recently identified as an ophiolitic tectonic m閘ange zone on the southern margin of the Qinling Belt[1—6]. The m?lange zone, stretching from east to west in the Mianxian-Lueyang region, represents a newly recog-nized Mianl黣 ophiolitic complex which is quite dif-ferent from the Shangdan ophiolite cropping out in the area between the North and South Qinling in terms of age and composition[1—6]. This paper is to present re-sults of geochemical studies ca…  相似文献   

Holocene activities of the Taigu fault zone, Shanxi Province, and their relations with the 1303 Hongdong M=8 earthquake     

谢新生  江娃利  王焕贞  冯西英 《地震学报(英文版)》2004,17(3)

Introduction The Taigu fault is located on the eastern boundary of the Jinzhong basin in the Shanxi fault depression system, which is one of the 12 major active basin boundary faults, and is also less studied among them. The reason for this is, firstly, the Jinzhong basin has no historical earth-quakes with M 7, while the two basins linked together in the northern and southern sides, the Linfen and Xinding basins all have had historical earthquakes with M 7; secondly, because the Jiaochen…  相似文献   

Seismic signal analysis based on the dual-tree complex wavelet packet transform     

谢周敏  王恩福  张国宏  赵国存  陈旭庚 《地震学报(英文版)》2004,17(Z1)

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裂谷盆地构造控制地形-沉积体系演化研究与面临问题   总被引：3，自引：1，他引：3  

于秀英  程日辉  王璞珺 《世界地质》2004,23(2):123-127

裂谷盆地早期构造作用强烈，充填作用发生在由构造控制的盆地内。盆地的古地形通过物源区侵蚀和沉积物流的盆内输送而影响沉积体的类型与堆积样式。断裂的生长、传播、相互作用、连接与死亡控制了古地形的周期演化，对沉积体系的演化施加了强烈的影响或控制。伸展盆地地层发育的控制与过程的研究主要反映在断层的生长过程、裂谷盆地的侵蚀、汇水和沉积物流等方面的精细研究。此方面研究面临的问题不仅包括研究的精细程度和技术，而且包括相关分支学科的合作。  相似文献   

西秦岭北缘中生代构造活动的^40Ar／^39Ar、FT热年代学证据   总被引：7，自引：3，他引：7  

郑德文张培震  万景林李大明 王非袁道阳  张广良 《岩石学报》2004,20(3):697-706

钾长石MDD和磷灰石裂变径迹研究表明，西秦岭北缘地区存在2次区域性快速冷却事件，分别为约230～210MaB．P．和约140～120Ma B．P．。约230～210Ma B．P．的快速冷却事件可能反映西秦岭秦岭洋于印支期闭合，发生了大规模的岩浆侵入活动，以及随后造山带迅速褶皱、隆升事件；140～120Ma B．P．的快速冷却事件与西秦岭北缘断裂以北的白垩纪盆地发育的时间一致，可能与西秦岭北缘隆升，同时其以北地区形成巨大的盆地有直接关系。同时，该事件与燕山运动主幕发生的时间一致，说明中燕山期我国东西部广大区域普遍存在一次构造运动。  相似文献   

Deep seismic sounding data reveal the crustal structures beneath Zoigê basin and its surrounding folded orogenic belts     

JIA ShiXu  ZHANG XianKang  ZHAO JinRen  WANG FuYun  ZHANG ChengKe  XU ZhaoFan  PAN JiShun  LIU Zhi  PAN SuZhen & SUN GuoWei Geophysical Exploration Center  China Earthquake Administration  Zhengzhou  China 《中国科学:地球科学(英文版)》2010,(2)

Songpan-Garze massif is located at the turning position of tectonics from the nearly west-east direction to the nearly north-south direction in the northeastern margin of Tibetan Plateau,with Zoigê basin in the centre of the massif.In this paper,we build a crustal structure model of Zoigê basin and its surrounding folded orogenic belts using the deep seismic sounding data in this region.We also discuss structures and properties of the basement in Zoigê basin,tectonic relations between Zoigê upland basin and its surrounding folded orogenic belts,crustal deformation and thickening in the northeastern margin of Tibetan Plateau,and decoupling and relaxing processes in the crust.The results indicate that a special "Mesozoic basement" is formed of Triassic rocks with high density (2.65-2.75 g/cm3) and high velocity (5.6 km/s) in Zoigê basin.Songpan-Garze tectonic massif was transformed into two types of tectonic units with different crustal structures,i.e.,relatively stable Zoigê upland basin and active folded orogenic belts around the basin,in the course of the crustal material of Tibetan Plateau flowing eastward and obstructed by surrounding stable blocks.The thickening of the crust in the northeastern margin of Tibetan Plateau mainly occurred in the mid and lower crust,and the structure characterized by low velocities and multiple reflectors obviously appears in the folded orogenic belts around Zoigê basin.It implies that the mid and lower crust underwent a strong tectonic deformation in the folded orogenic areas.The thickness of the crust is about 50 km in Zoigê basin and the folded orogenic belts at the both southern and northern sides of Zoigê basin.The "Mountain root" cannot be identified.It is inferred that during the later orogenic period the eastwards flowing deep materials moved clockwise along the relatively relaxing southern side around the eastern tectonic knot under the obstructing of surrounding rigid massifs,and it resulted in the strong stretching action of the folded orogenic belts around Zoigê basin.  相似文献   

Systematic examination of ‘precursor waves' of strong earthquakes by using the wavelet method     

Longshou Zhou Zehua Qiu Lei Tang Baoxiang Kan Institute of Crustal Dynamics  China Earthquake Administration  Beijing  China 《地震学报(英文版)》2009,(1)

Based on the borehole strainmeter recordings immediately before the strong earthquakes(MS≥7.5) during the period from 2001 to 2005 observed at the Taian observation station,Shandong Province,the authors make a systematic and objective examination of the precursor waves of the quakes.The effects of Earth tides with periods larger than 128 min are eliminated through high-pass filtering;and atmospheric-pressure inferences are removed by linear regression.The 2-128 min signals are then separated into six freque...  相似文献