The Glarus thrust: excursion guide and report of a field trip of the Swiss Tectonic Studies Group (Swiss Geological Society, 14.–16. 09. 2006)     

Marco Herwegh  Jean-Pierre Hürzeler  O. Adrian Pfiffner  Stefan M. Schmid  Rainer Abart  Andreas Ebert 《Swiss Journal of Geoscience》2008,101(2):323-340

This excursion guide results form a field trip to the Glarus nappe complex organized by the Swiss Tectonic Studies Group in 2006. The aim of the excursion was to discuss old and recent concepts related to the evolution of the Glarus thrust. The major aspects were (i) the interplay between deformation, fluid flow and geochemical alteration, (ii) episodic versus continuous deformation and fluid flow, and (iii) the link between large-scale structures, microstructures, and geochemical aspects. Despite 150 years of research in the Glarus nappe complex and the new results discussed during the excursion, there exist controversies that still are unsolved.  相似文献   

浙闽山区茶叶生产基地评价的探讨   总被引：6，自引：0，他引：6  

华熙成 《地理研究》1994,13(3):98-103

茶叶基地的评价包括对基地的自然和经济条件的评估,应用系统分析方法,将自然和经济条件进行定量的综合评估,用综合评价值区分基地间的差异,最后定性与定量相结合,提出茶叶生产基地的合理布局.  相似文献   

A combined study of macroseismic data and focal mechanisms applied to the West-Bohemian earthquake,Czechoslovakia     

J. Zahradník  M. Antonini  G. Grünthal  J. Janský  D. Procházková  E. Schmedes  A. Špičak  J. Zedník 《Pure and Applied Geophysics》1990,133(1):53-71

The main shock of the West-Bohemian earthquake swarm, Czechoslovakia, (magnitudem=4.5, depthh=10 km) exhibits an irregular areal distribution of macroseismic intensities 6° to 7° MSK-64. Four lobes of the 6° isoseismal are found and the maximum observed intensity is located at a distance of 8 km from the instrumentally determined epicentre. This distribution can be explained by the energy flux of the directS wave generated by a circular source, the hypocentral location and focal mechanism of which are taken from independent instrumental studies. The theoretical intensity, which is assumed to be logarithmically proportional to the integrated squared ground-motion velocity (i.e.,I=const+log v ² (t)dt), fits the observed intensity with an overall root-mean-square error less than 0.5°. It is important that the present intensity data can also be equally well explained by the isotropic source. The fit was attained by means of a horizontally layered model though large fault zones and an extended sedimentary basin suggest a significant lateral heterogeneity of the epicentral region. The results encourage a broader application of the simple modelling technique used.  相似文献   

Quantification of the risk associated with high levels of mercury pollution at Temirtau, Kazakhstan     

Huiwen HSIAO Susanne M. Ullrich Trevor W. Tanton 《中国地球化学学报》2006,25(B08):233-233

This research aims to establish the risks of hurnan exposure to modeling approach. The study site was located on the River Nura 1990s, an acetaldehyde production plant located in the industrial high environmental mercury levels, based on a quantitative risk in central Kazakhstan. From the 1950s until its closure in the mid city of Temirtau released mercury-containing wastewater into the river. River sediments are highly contaminated with mercury up to a distance of 25 km and beyond. In addition, a local power station released an estimated 6 million tonnes of fly-ash into the water and the mercury has become quite tightly associated with the ash deposits. River water, fish and agricultural land in the floodplain are also contaminated with mercury, yet the risks posed to the local population have not been evaluated to date. In June and July 2005, we took samples of soil, interior and exterior dust, drinking water, and food from individual households, communal areas and markets. Additionally, water and sediment samples and fish were taken from the river. Interviews were conducted with householders to establish their age and body weight, general living conditions and sources of irrigation and drinking water. A food frequency questionnaire （FFQ） was designed to investigate the frequencies of consumption of several common regional food items, including fish from the fiver and/or local market. Human hair samples were also collected to estimate the mercury bioburden and to enable the validity of the modeling approach to be established. The paper expands on the main pathways of contamination and looks at linkages between exposure pathways and mercury concentrations found in human hair. Uncertainties inherent in risk analysis as well as their influence on the relative importance of different exposure routes are also discussed.  相似文献   

Time domain Gauss–Newton seismic waveform inversion in elastic media     

Dong-Hoon Sheen  Kagan Tuncay  Chang-Eob Baag  Peter J. Ortoleva 《Geophysical Journal International》2006,167(3):1373-1384

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地震信号的相位恢复及误差分析     

WU Yuan-yuan LIU Cai WANG Dian WANG Shi-yu College of GeoExploration Science  Technology  Jilin University  Changchun  China 《吉林大学学报(地球科学版)》2006,(Z2)

常见的几种地震子波有:零相位子波、最小相位子波、最大相位子波和混合相位子波。以不同类型的信号为激发子波,对不同地层模型合成地震道。仅用原始合成地震道记录的振幅谱来恢复原始记录,讨论不同方法下,由于激发子波的不同,对比分析原始记录与恢复记录的差异,及其恢复效果。  相似文献   

油气成藏机理研究进展和前沿研究领域   总被引：23，自引：7，他引：23  

郝芳  邹华耀  王敏芳  杨旭升 《地质科技情报》2002,21(4):7-14

随着地质工作者刻划和认识地下地质体构成、结构的能力及研究和预测沉积盆地能量场（温度场、压力场和应力场）及其演化能力的不断提高，以流体流动和油气运移为核心的油气成藏机理研究取得了重要进展：（1）证实了油气的优势通道运移并妆步提示了优势运移通道的微观和宏观控制机制，从而使基于油气运移路径三维预测的油气藏定位预测成为可能；（2）证实了幕式快速成藏过程并初步揭示了幕式成藏的驱动机制、有利场所和地球化学识别标志，突破了油气成藏是一个缓慢渗流过程的传统模式；（3）深盆气勘探和成藏机理研究取得了进展，从而突破了背斜成藏的传统观念，使“向斜”（盆地凹陷区）成为一些盆地寻找大型天然气藏的重要场所。沉积盆地深层油气成藏过程和保存条件、活动构造背景下油气晚期快速成藏过程是油气成藏机理研究的重要前沿研究领域。  相似文献   

The Mw = 6.0, 7 September 1999 Athens Earthquake     

Papadimitriou  P.  Voulgaris  N.  Kassaras  I.  Kaviris  G.  Delibasis  N.  Makropoulos  K. 《Natural Hazards》2002,27(1-2):15-33

On 7 September 1999 at 11:56 GMT a destructive earthquake (M_w = 6.0) occurred close to Athens (Greece). The rupture process is examined using data from the Cornet local permanent network, as well as teleseismic recordings. Data recorded by a temporary seismological network were analyzed to study the aftershock sequence. The mainshock was relocated at 38.105°N, 23.565°E, about 20 km northwest of Athens. Four foreshocks were also relocated close to the mainshock. The modeling of teleseismic P and SH waves provides a well-constrained focal mechanism of the mainshock (strike = 105°, dip = 55° and rake = -80°) at a depth of 8 km and a seismic moment M₀ = 1.010²⁵ dyn·cm. The obtained fault plane solution represents normal faulting indicating an almost north-south extension. More than 3500 aftershocks were located, 1813 of which present RMS < 0.1 s and ERH, ERZ < 1.0 km. Two main clusters were distinguished, while the depth distribution is concentrated between 2 and 11 km. Over 1000 fault plane solutions of aftershocks were constrained, the majority of which also correspond to N–S extension. No surface breaks were observed but the fault plane solution of the mainshock is in agreement with the tectonics of the area and with the focal mechanisms obtained by aftershocks. The hypocenter of the mainshock is located on the deep western edge of the fault plane. The relocated epicenter coincides with the fringe that represents the highest deformation observed on the differential interferometric image. The calculated source duration is 5 sec, while the estimated dimensions of the fault are 15 km length and 10 km width. The source process is characterized by unilateral eastward rupture propagation, towards the city of Athens. An evident stop phase observed in the recordings of the Cornet local stations is interpreted as a barrier caused by the Aegaleo Mountain.  相似文献   

Modelling and imaging the Moho transition: the case of the southern Urals   总被引：2，自引：0，他引：2  

R. Carbonell  J. Gallart  A. Pérez-Estaún 《Geophysical Journal International》2002,149(1):134-148

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大兴安岭浅覆盖区生态地质评价方法初探——以1∶25万区调呼中镇幅为例   总被引：1，自引：0，他引：1       下载免费PDF全文

马江水李仰春  任凤和尤福珍 李清伟 《中国地质》2003,30(3):330-336

通过野外调查，在收集统计大量基础地质、经济地质、环境地质、旅游地质、农(林)业地质等数据信息的基础上，在GIS技术指导下，采用定量定性相结合的半定量分析评价方法，对森林浅覆盖区生态地质现状及各类资源的开发利用潜力进行了综合评价。在研究和探讨森林浅覆盖区生态地质综合评价方法的基础上，提出了森林浅覆盖区生态地质评价模型，确定了综合参数，划分了生态地质类型。  相似文献