CCSD主孔100-2950m榴辉岩类和片麻岩类叶理及微断层产状特征   总被引：1，自引：0，他引：1  

唐哲民 《岩石矿物学杂志》2005,24(5):438-442

CCSD主孔100~2950m榴辉岩、退变榴辉岩类岩石叶理倾角明显较片麻岩类岩石叶理倾角陡,前者总体倾角55°左右,后者28°左右,局部可见片麻岩类叶理切割榴辉岩类叶理,因此两者叶理可能形成于不同时期;两类岩石之间现部分为韧性剪切带接触关系,韧性剪切带形成于苏鲁地体折返主期自SEE向NWW的韧性剪切作用。榴辉岩、退变榴辉岩类岩石叶理产状对发育于该类岩石内的微断层产状有一定控制作用,而片麻岩类岩石叶理产状对发育于该类岩石内的微断层产状控制作用相对较弱。孔区脆性变形主要反映白垩纪以来SEE-NWW向伸展构造应力场的变形特征,主孔100~1620m倾伏向以SEE向占绝对优势的微正滑断层擦痕即为该期变形的产物。  相似文献   

青藏高原中部的东西向扩张构造运动   总被引：3，自引：0，他引：3  

徐纪人赵志新  石川有三 《岩石矿物学杂志》2005,24(5):447-452

系统分析了1933~2003年间青藏高原及其周缘发生的745个中、强地震的震源机制解,研究了高原地壳构造运动及其动力学特征。结果表明,大量正断层型地震集中发生在青藏高原中部海拔4000m以上的地区,其中许多地震是纯正断层型地震。震源机制结果显示,该区正断层型地震的断层走向多为南北方向,断层位错矢量的水平分量均位于近东西方向,这表明青藏高原高海拔地区存在着近东西方向的扩张构造运动。地震震源应力场的研究结果表明,在高原中部高海拔地区,E-W向或WNW-ESE向的水平扩张作用控制着该区的地壳应力场。青藏高原高海拔地区近东西方向的扩张构造运动是该区引张应力场的作用结果,其动力学原因可能与持续隆升的高原自重增大引起的重力崩塌及其周边区域构造应力状况有关。而青藏高原周缘地区,除了东部边缘外,南部的喜马拉雅山前沿以及青藏高原的北部、西部边缘所发生的绝大部分地震都是逆断层型或走滑逆断层型地震。在青藏高原周缘地区,北东或者北北东方向水平挤压的构造应力场为优势应力场。在中国西部的大范围内,主压应力P轴水平分量位于NE-SW方向,形成了一个广域的NE-SW方向的挤压应力场。青藏高原及其周缘应力场特征表明,印度板块的北上运动以及它与欧亚板块之间的碰撞所形成的挤压应力场是高原强烈隆起的直接原因。在青藏高原中南部形成了近东西向引张应力场为主的区域,并以东西向扩张构造运动部分释放其应力积累。研究高原高海拔地区的引张应力场和近东西向扩张构造运动的特征,对于认识青藏高原强烈隆起的地球动力学过程与机制,有着重要的理论意义。  相似文献   

淄博市张店南部地热异常成因   总被引：1，自引：0，他引：1  

杨澍  张宏达  李卫中  吴琳 《水文地质工程地质》2005,32(3):59-62

通过研究井温曲线类型,确定研究区纯传导地温梯度为2 5℃100m;结合各单井地温梯度,圈定了地热异常区域;揭示了该区地热异常具有下段以对流为主、上段以传导为主的特点。通过热水水化学和同位素数据的综合分析表明,该区地下热水补给来源为大气降水,热水赋存于断裂裂隙系统中,且沿断裂裂隙垂向运动十分强烈。  相似文献   

小波分析与C3相干体在小断层解释中的应用     

许丽  刘磊  邢延团 《煤田地质与勘探》2005,33(6):71-73

利用小波分析的分频特性及C3相干数据体比常规振幅数据体具有更高的构造分辨能力的特点,将小波分析与C3相干体两种方法相结合,用来识别煤矿采区小尺度构造,特别是识别小断层.实际应用表明,利用小波分析与C3相干体可更加精细地揭示断层等构造信息,提高小断层识别能力.  相似文献   

多边形断层系及其研究现状     

余一欣  汤良杰  宋纯利 《世界地质》2005,24(2):149-153

多边形断层为一类非构造断层，主要分布于深水环境下的细粒沉积物中。它的形成与沉积物的早期压实作用和流体排出作用有关。多边形断层系的识别主要通过时间切片分析和地震剖面解释等手段进行。研究表明，多边形断层系发育一般要经历3个阶段，即超压封存箱的形成、密度反转和多期水力压裂作用。对多边形断层系的研究有助于泥岩压实、油气运移、泥岩中流体活动状态以及对深水砂体分布和几何形态特征的分析等。由于我国还未发现有多边形断层系的存在，希望本文的介绍能为我国开展此类断层研究时有所帮助。  相似文献   

Active Fault and Volcanic Activity in the Longhai-Zhangpu Coastal Area, Fujian Province     

Huang Qingtuan 《中国地震研究》2005,19(2):214-223

INTRODUCTION TheLonghai ZhangpucoastalareaofFujianProvinceliesonthesouthernsideoftheoutletofthe JiulongjiangRiver.Tectonically,itislocatedonthesouthernsegmentoftheChangle Zhao’anfault zone.Previously,alotofseismogeologicresearchworkhasbeencarriedoutinthi…  相似文献   

Paleo-earthquake studies on the eastern section of the Kunlun fault   总被引：1，自引：0，他引：1  

李春峰  贺群禄  赵国光 《地震学报(英文版)》2005,18(1):64-71

Introduction East Kunlun active fault is one of the largest sinistral slip fault zones in northern Tibetan Pla-teau. The fault tails primarily after the ancient eastern Kunlun suture zone, which was reactivatedby the northward subduction of the Indian plate beneath the Eurasian plate. The western end of thefault starts near the western flank of the Buxedaban peak in Qinghai Province. The fault then ex-tends eastwards through the Kusai Lake, Xidatan, Dongdatan, Alag Lake, Tuosuo Lak…  相似文献   

The dependence of response spectrum on the tectonic ambient shear stress field     

李保昆  陈培善  白彤霞 《地震学报(英文版)》2005,18(3):313-321

Introduction The acceleration response spectrum and peak ground acceleration are the necessary and im-portant parameters in earthquake-resistant design at present. They are still active research field. With the increase of digital high accurate strong motion observation data, especially the earth-quakes of Loma Prieta (M=7.0) in 1989; Landers (M=7.3) in 1992; Big Bear (M=6.4) in 1994 and Northridge (M=6.7) in 1994 in USA; Kozani (M=6.6) earthquake and afteshocks in 1995 in Greece; Dinar…  相似文献   

Crust and upper mantle structure of the Ailao Shan-Red River fault zone and adjacent regions   总被引：4，自引：1，他引：4  

XU Yi  LIU Jianhua  LIU Futian  SONG Haibin  HAO Tianyao & JIANG Weiwei Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing  China 《中国科学D辑(英文版)》2005,48(2):156-164

Using arrival data of the body waves recorded by seismic stations, we reconstructed the velocity structure of the crust and upper mantle beneath the southeastern edge of the Tibetan Plateau and the northwestern continental margin of the South China Sea through a travel time tomography technique. The result revealed the apparent tectonic variation along the Ailao Shan-Red River fault zone and its adjacent regions. High velocities are observed in the upper and middle crust beneath the Ailao Shan-Red River fault zone and they reflect the character of the fast uplifting and cooling of the metamorphic belt after the ductile shearing of the fault zone, while low velocities in the lower crust and near the Moho imply a relatively active crust-mantle boundary beneath the fault zone. On the west of the fault zone, the large-scale low velocities in the uppermost mantle beneath western Yunnan prove the influence of the mantle heat flow on volcano, hot spring and magma activities, however, the upper mantle on the eas  相似文献   

On the Importance of Geolithological Features for the Estimate of the Site Response: The Case of Catania Metropolitan Area (Italy)     

G. Lombardo  H. Langer  S. Gresta  R. Rigano  C. Monaco  G. De Guidi 《Natural Hazards》2006,38(3):339-354

The evaluation of seismic site response in the urban area of Catania was tackled by selecting test areas having peculiar lithological and structural features, potentially favourable to large local amplifications of ground motion. The two selected areas are located in the historical downtown and in the northern part of Catania where the presence of a fault is evident. Site response was evaluated using spectral ratio technique taking the horizontal- to-vertical component ratio of ambient noise. Inferences from microtremor measurements are compared with results from synthetic accelerograms and response spectra computed at all drillings available for this area. Such method is particularly suitable in urban areas where the nature of the outcropping geological units is masked by city growth and anthropic intervention on the surface geology. The microtremor H/V spectral ratios evaluated at soft sites located within the downtown profile tend to be smaller than that usually reported in the literature for such soils. A tendency for amplifications to peaks near 2 Hz is observed only in some sites located on recent alluvial deposits. Evidences for amplifications of site effects (frequency range 4–8 Hz) were observed in the sampling sites located on the fault, with a rapid decrease of spectral amplitude just a few tenths of metres away from the discontinuity. Numerical simulations evidenced the importance of geolithological features at depth levels even greater than 20–30 m. Besides this, the results strongly confirm the importance of the subsurface geological conditions, in the estimate of seismic hazard at urban scale.  相似文献