滇中小江走滑剪切带晚新生代挤压变形研究   总被引：11，自引：1，他引：11       下载免费PDF全文

王二七 Burc.  BC 《地质科学》1995,30(3):209-219

对滇中小江走滑剪切带中的挤压变形作用进行研究发现,尽管这些变形多发生于中元古界昆阳群浅变质岩中,其形成时代却可能是第三纪末和第四纪初,和小江断裂带的走滑运动有成因关系,并导致了走滑位移量的衰减。昆阳群的隆起可能主要是第四纪变形的结果。  相似文献   

新疆及其邻区的地震窗前兆与短期地震预报   总被引：2，自引：0，他引：2  

敖雪明  王桂岭 《内陆地震》1993,7(2):121-127

根据新疆及毗邻的独联体部分国家区域台网微震观测记录,通过普查与统计检验,筛选出22个具有较高短期预报效能的地震窗。较系统地研究了地震窗小震月频度的前兆特征及其用于短期地震预报的判据指标,着重介绍了近两年新疆与独联体科技合作的最新成果,同时给出若干成功预报震例,并对所得结果的可能物理机制等问题进行了讨论。  相似文献   

定向井侧钻技术          下载免费PDF全文

张岚  蔡长宇 《探矿工程》1994,(5):38-41

结合我国首例定向井双重套管开窗例钻修井实例，详述了定向井侧钻工艺及其应用效果，介绍了提高定向井侧钻效率、降低成本的方法，指出定向井开窗成败主要取决于导斜器的安装方位。  相似文献   

A Simplified Technique for Simulating Wide-band Strong Ground Motion for Two Recent Himalayan Earthquakes   总被引：1，自引：0，他引：1  

A.?JoshiEmail author 《Pure and Applied Geophysics》2004,161(8):1777-1805

A simplified technique for simulation of wide-band strong motion based on simple regression relations and Empirical Greens Function (EGF) technique by Irikura (1986) is presented in this paper. The method uses the acceleration envelope as a shaping window for a filtered white Gaussian noise, to get the synthetic accelerogram from each subfault. Correction factors for slip of large and small events and transmission factors at each boundary of different layers are included in this synthetic accelerogram. The synthetic accelerogram obtained from each subfault is used as the Greens function to get resultant records. Simulations are made for the confirmed models of the Uttarkashi and the Chamoli earthquakes at a number of stations to get wide-band strong ground motion. The comparison of synthetic with the observed records over a wide range of frequencies for two different Himalayan earthquakes establishes the efficacy of the present technique.  相似文献   

基于有向窗的自适应SIGMA中值滤波算法   总被引：4，自引：0，他引：4  

许才军  王华  王江林  GE Linlin 《武汉大学学报(信息科学版)》2005,30(10):873-876

提出了一种能够有效消除InSAR DEM噪声的自适应中值滤波算法:基于有向窗的自适应SIGMA中值滤波。分别采用中值滤波、基于高程的自适应SIGMA中值滤波和基于有向窗的自适应SIGMA中值滤波算法,对InSAR Tandem DEM和模拟DEM进行了滤波处理。结果表明,基于有向窗的自适应SIGMA中值滤波算法不仅能够更有效地消除噪声,而且能够更好地保留图像的边界特征。  相似文献   

Petrogenesis of the Eocene and Mio–Pliocene alkaline basaltic magmatism in Meseta Chile Chico, southern Patagonia, Chile: Evidence for the participation of two slab windows     

Felipe Espinoza  Diego Morata  Ewan Pelleter  Ren  C. Maury  Manuel Su  rez  Yves Lagabrielle  Mireille Polv    Herv  Bellon  Joseph Cotten  Rita De la Cruz  Christelle Guivel 《Lithos》2005,82(3-4):315-343

The Meseta Chile Chico (MCC, 46.4°S) is the westernmost exposure of Eocene (lower basaltic sequence, LBS; 55–40 Ma, K–Ar ages) and Mio–Pliocene (upper basaltic sequence, UBS; 16–4 Ma, K–Ar ages) flood basalt volcanism in Patagonia. The MCC is located south of the Lago General Carrera-Buenos Aires (LGCBA), southeast from the present day Chile Triple Junction (CTJ), east of the actual volcanic gap between Southern South Volcanic Zone and Austral Volcanic Zone (SSVZ and AVZ, respectively) and just above the inferred location of the South Chile Ridge segment subducted at 6 Ma (SCR-1). Erupted products consist of mainly ne-normative olivine basalt with minor hy-normative tholeiites basalt, trachybasalt and basanite. MCC lavas are alkaline (42.7–53.1 wt.% SiO₂, 3–8 wt.% Na₂O+K₂O) and relatively primitive (Ni: 133–360 ppm, Cr: 161–193 ppm, Co: 35–72 ppm, 4–16.5 MgO wt.%). They have a marked OIB-like signature, as shown by their isotopic compositions (⁸⁷Sr/⁸⁶Sr_o=0.70311–0.70414 and εNd=+4.7–+5.1) and their incompatible trace elements ratios (Ba/La=10–20, La/Nb=0.46–1.09, Ce/Pb=15.52–27.5, Sr/La<25), reflecting deep mantle origin. UBS-primitive lavas have characteristics similar to those of the Eocene LBS basalts, while UBS-intermediate lavas show geochemical imprints (La/Nb>1, Sr/La>25, low Ce/Pb, Nb/U) compatible with contamination by arc/slab-derived and/or crustal components. We propose that the genesis and extrusion of magmas is related to the opening of two slab windows due to the subduction of two active ridge segments beneath Patagonia during Eocene and Mio–Pliocene.  相似文献   

煤田三维地震数据处理中方差体 技术的参数优选及应用效果     

张新红  蒋传琳  刘卫  尚照顺 《物探与化探》2006,30(5):450-452,455

方差体技术是基于统计学原理,利用三维地震数据体中相邻道之间地震信号的相关性计算样点的方差值,提取数据体中不连续信息,用以识别小断层和陷落柱等岩性变化点。笔者以山西某煤矿采区为例,通过方差体各项参数的测试,介绍方差体的运算模式、运算道数和时窗大小等参数对计算成果的影响,使方差体技术在确定煤层小断层和陷落柱等地质体时取得较好效果。  相似文献   

Carbogaseous spring waters, coldwater geysers and dry CO₂ exhalations in the tectonic window of the Lower Engadine Valley, Switzerland     

Pius Bissig  Nico Goldscheider  Jo?lle Mayoraz  Heinz Surbeck  Fran?ois-David Vuataz 《Eclogae Geologicae Helvetiae》2006,99(2):143-155

  相似文献   

霍山"震情窗"地区流动地磁S异常与华东中强地震相关性的研究   总被引：1，自引：0，他引：1  

刘义高  郑志坤  翟义勇  张毅 《华北地震科学》2002,20(4):34-39

以霍山“震情窗”地区流动地磁测线的S值变化,预测霍山“震情窗”相关地区－华东地区中强地震,研究结果表明：“震情窗”地区流动地磁测线的S值异常与距离霍山“震情窗”R＜500km的华东中强地震有明显的相关性。  相似文献   

滇西水汞观测的地震短临预报指标   总被引：2，自引：0，他引：2  

郭绍忠  黄绍裘 《地震研究》1998,21(1):50-57

通过对滇西下关,弥渡,洱源江干,洱源滇２０＃,保山等水汞在１２次地震前异常特征分析的结果表明,汞异常形态清楚,异常变化率大,单项以多点突跳为主,整体以群体突跳为主,短临异常持续时间数十天,地震多数发生在首次异常后２３－１１１天的８８天之内;大震存在中短期异常和时空演变规律,对应地震范围受震中距和地震构造的双重制约,似乎与孕震能大小和传播途径有关,大体存在的异常持续时间越长,异常数量越多,震级越大的  相似文献