福建浦城－三都澳成矿带几个成矿作用问题的探讨   总被引：1，自引：0，他引：1  

姜耀辉  陈鹤年  巫全淮  黄树峰  郑惠文 《福建地质》1994,(3)

浦城－三都澳是福建省内较为重要的铜金银多金属成矿带。该成矿带已开展了不少地质工作。本文着重就物源、水源、热源以及东带与西带成矿条件的差异等几个成矿作用问题作些探讨。  相似文献   

岩体结构面粗糙度系数JRC的定向统计研究   总被引：5，自引：2，他引：5  

杜时贵 《工程地质学报》1994,(3)

本文回顾了岩体结构面粗糙度系数ＪＲＣ的研究成果，分析了各种ＪＲＣ研究方法的应用范围。在野外实际结构面形态的详细调查和深入研究的基础上，发展了Ｂａｒｔｏｎ直边法，并提出按岩性定向统计研究结构面粗糙度系数ＪＲＣ的科学思想。  相似文献   

Frictional heat generation and seismic radiation in a foam rubber model of earthquakes   总被引：1，自引：0，他引：1  

Abdolrasool Anooshehpoor  James N. Brune 《Pure and Applied Geophysics》1994,142(3-4):735-747

Results from a study of stick-slip particle motion at the interface between two stressed foam rubber blocks indicate that normal vibrations and interface separation are an important part of the stick-slip process in foam rubber. The dimension of the dynamic slip pulse is small compared to the dimension of the model (approximately 10 cm vs. 200 cm) consistent with the abrupt-locking slip pulse model ofBrune (1970, 1976), andHeaton (1990). A comparison of frictional heat generation between stable-sliding and stick-slip foam rubber models indicates a linear relation between the temperature increase on the fault surface (for a given distance of slip) and the driving shear force for the stable-sliding model, while for the stick-slip model there is essentially no variation in frictional heat generation with an increase in shear stress. We performed experiments to investigate the ratio of normal motion to shear motion at different levels of normal stress in the stick-slip foam rubber model. Preliminary result indicate that the normal component of the particle motion increases more rapidly with increasing normal stress than the shear component. The phenomenon of interface separation and normal vibrations may thus explain some of the most frustrating problems in earthquake mechanics, e.g., the heat flow paradox, the long-term weakness of major active faults, and anomalousP-wave radiation.  相似文献   

Prediction of tension crack location and riverbank erosion hazards along destabilized channels     

Stephen E. Darby  Colin R. Thorne 《地球表面变化过程与地形》1994,19(3):233-245

Riverbank erosion, associated sedimentation and land loss hazards are a land management problem of global significance and many attempts to predict the onset of riverbank instability have been made. Recently, Osman and Thorne (1988) have presented a Culmann-type analysis of the stability of steep, cohesive riverbanks; this has the potential to be a considerable improvement over previous bank stability theories, which do not account for bank geometry changes due to toe scour and lateral erosion. However, in this paper it is shown that the existing Osman-Thorne model does not properly incorporate the influence of tension cracking on bank stability since the location of the tension crack on the floodplain is indirectly determined via calculation or arbitrary specification of the tension crack depth. Furthermore, accurate determination of tension crack location is essential to the calculation of the geometry of riverbank failure blocks and hence prediction of land loss and bank sediment yield associated with riverbank instability and channel widening. In this paper, a rational, physically based method to predict the location of tension cracks on the floodplain behind the eroding bank face is presented and tested. A case study is used to illustrate the computational procedure required to apply the model. Improved estimates of failure block geometry using the new method may potentially be applied to improve predictions of bank retreat and floodplain land loss along river channels destabilized as a result of environmental change.  相似文献   

土地类型系列制图的几个理论问题   总被引：1，自引：0，他引：1  

蔡运龙 《地理研究》1994,13(1):76-83

实际存在的不同尺度地域分异规律是土地类型系列制图的客观基础。多种尺度制图构成的土地类型系列制图可以全面揭示区域土地类型的形成因素、分布规律和空间结构特征,也为不同层次土地规划管理之间的相互补充、协调提供了重要基础。  相似文献   

Long-period surface waves and mantle boundary undulations   总被引：2，自引：0，他引：2  

Michael H. Ritzwoller  Eugene M. Lavely 《Geophysical Journal International》1994,116(1):205-216

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Influence of Mantle Compressibility and Ocean Warping On Dynamical Models of the Geoid     

Catherine Thoraval  Philippe Machetel  Anny Cazenave 《Geophysical Journal International》1994,117(2):566-573

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盆地模拟技术中的化学动力学生烃模型与应用     

赵永军  李汉林  查明 《地质论评》1994,40(7):84-89

油气地表化探数据的失真(特别是数据中的高值失真点)直接影响到化探异常圈定。本文根据油气地表化探数据的分布特点，利用概率统计原理，提出一种适合油气化探资料前期处理的失真数据的概率判定方法和处理手段，在对实际资料的应用中，取得了良好的效果。  相似文献   

Radiometric dating of lake sediments from Signy Island (maritime Antarctic): evidence of recent climatic change   总被引：4，自引：0，他引：4  

P. G. Appleby  V. J. Jones  J. C. Ellis-Evans 《Journal of Paleolimnology》1995,13(2):179-191

Sediment cores from three lakes (Moss, Sombre and Heywood) in the maritime Antarctic (Signy Island, South Orkney Islands) have been successfully dated radiometrically by²¹⁰Pb and¹³⁷Cs. The core inventories of both fallout radionuclides are an order of magnitude higher than that which can be supported by the direct atmospheric flux at this latitude. The elevated values may be explained by fallout onto the catchment during the winter being delivered directly to the lakes during the annual thaw. Two of the lakes (Sombre and Heywood) show marked increases in sediment accumulation afterc. 1950. This appears to be associated with a documented rise in temperature in the South Orkney Islands, which has caused extensive deglaciation at Signy Island.This is the tenth of a series of papers to be published by this journal following the 20 ^th anniversary of the first application of²¹⁰Pb dating of lake sediments. Dr P.G. Appleby is guest editing this series.  相似文献   

Surface-wave mode coupling for efficient forward modelling and inversion of body-wave phases     

Henk Marquering  Roel Snieder 《Geophysical Journal International》1995,120(1):186-208

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