中国火山岩地区金的成矿环境及分布规律   总被引：5，自引：1，他引：5  

王碧香  杨岳清  史仁灯  银剑钊  石森 《矿床地质》1997,16(1):11-20,40

中国是一个火山岩广泛分布的国家，火山岩区的金矿不论其数量和储量在全国均占有重要地位，根据金和火山活动的关系，可划分出６种金矿类型，它们主要分布在６个火山岩区中，不同地区金的成矿作用各有其特色，总体可概括出７条成矿特征，这对于在我国广阔的火山岩区寻找金矿具有重要的指导意义。  相似文献   

YGQ—89／43型双作用冲击器微机电算分析     

李国民  蒋荣庆 《世界地质》1997,16(4):83-86

通过微机模拟仿真电算，分析ＹＧＱ－８９／４３型冲击器结构参数的变化对冲击器性能的影响规律，从而找出调节冲击器性能的有效方法，指导设计和生产使用。  相似文献   

赣西北地区修水县联测图组1：5万区调主要进展与体会   总被引：3，自引：0，他引：3  

章泽军  印纯清 《江西地质》1997,11(2):74-80

本文重点总结赣西北地区修水县联测图１∶５万区调取得的主要进展与区调方法上的创新。其中，在中元古界双桥山群浅变质岩系中所识别、填绘出的近东西向紧闭同斜倒转褶皱，叠加近南北向开阔圆滑褶皱，在中小型陆相红盆中探索出的运用数理统计与沉积学研究相结合确定冲积扇体，并用扇体与岩性段双重方法予以图面表达以及第四纪研究成果等取得的重要进展。此外，就有关提高区调质量等问题浅谈其体会。  相似文献   

The Natural Probability Distribution of Load and Unload Response Ratio     

Chen Qifu  Yin Xiangchu  and Ma LiCenter for Analysis  Prediction  SSB  Beijing  China 《中国地震研究》1997,(1)

In this paper,the Gutenberg-Richter model is used to generate seismic events.The events that satisfy the random distribution are also generated.With those events,the natural probability distribution of Load and Unload Response Ratio(LURR),which measures quantitatively the degree of instability of a nonlinear system,is discussed.The study is based on stress energy release,which is chosen as the response of nonlinear system F3.The comparative results from the observation catalogue and generating data are also studied.It is revealed that the natural probability of LURR is mostly stable when the sample number is sufficient.The lower the natural probability of LURR,the more the precursory is information it may contain.The influence of Y3 resulting from the sample number and the magnitude range of events is also discussed.  相似文献   

Evolution of Quaternary groundwater system in North China Plain   总被引：4，自引：0，他引：4  

Zonghu Zhang  Dehong Shi  Fuhong Ren  Zhengzhou Yin  Jichao Sun  Cuiyun Zhang 《中国科学D辑(英文版)》1997,40(3):276-283

The Quaternary groundwater system in the North China Plain is formed mainly through the terrestrial water flow action on the united geological and tectonic backgrounds. The analysis of groundwater dynamic field, simulation of groundwater geochemistry, and the¹⁴C dating and extraction of isotope information have provided more evidence for recognizing and assessing the evolution of groundwater circulation system and studying the past global changes. The exploitation and utilization of groundwater on a large scale and overexploitation have given rise to the decline of regional groundwater level, change of flow field, decrease of water resources and downward movement of saline water body. The water environment has entered a new evolution stage in which it is intensely disturbed by the mankind’s activities. Project supported by the National Natural Science Foundation of China.  相似文献   

利用地下水预报河南登封4.7级地震的资料分析过程     

孙佩琦  尹芳欣 《山西地震》1997,(4):40-42

通过对１９９２年河南登封４．７级地震的资料分析，表明拐河老井地下水位变化是区域应力场的变化效应。在时间上有连续性，在空间上和构造体系上有一定的相关性  相似文献   

Sequence Stratigraphy of the Permian--Triassia Boundary Section of Changxing, Zhejiang, Southern China   总被引：1，自引：0，他引：1  

Zhang Kexin  Tong Jinnan  Yin Hongfu  Wu Shunbao China University of Geosciences  Wuhan  Hubei 《《地质学报》英文版》1997,71(1):90-103

Three third-order sequences and about one hundred high-frequency cycles or Milankovitchcycles within the Late Permian Changxingian to Early Triassic Griesbachian are identified in theMeishan Section of Changxing, Zhejiang Province, southern China, the candidate stratotype sec-tion of the global Permo-Triassic boundary, based on a detailed study of the biological,ecological and high-resolution allochthonous cyclic events, microfacies and depositional systems.Furthermore, the stacking pattern of the depositional systems across various Changxingian andGriesbachian sedimentary facies of the Lower Yangtze and the sequence stratigraphic frameworkare outlined with the Meishan section as the principal section. In this paper the habitat types offossil biota are applied to semiquantitative palaeobathymetry and the study of relative sea levelchanges.  相似文献   

地史转折期的生态系   总被引：7，自引：2，他引：7  

殷鸿福  童金南 《地学前缘》1997,(Z2)

生态系的演变是地球各圈层系统耦合关系变化的直接标志。地史转折期的生态系具有复杂的生物内涵，在绝灭—残存—复苏过程中，各生物类别的演替遵循着一定的生存型式。大绝灭后生态系复苏的原动力是绝灭后迁入避难所的复活类型和大绝灭末期高压环境中产生的祖先类型的新生和辐射发展。全面了解绝灭后生态系的组成和结构，对于正确认识地史转折期，即圈层耦合结点处的地质作用型式和过程具有重要作用。  相似文献   

地震孕育体源流变模型--位移与应变场     

宋治平  尹祥础  梅世蓉 《国际地震动态》2004,(Z1):3

由于岩石介质在温度较低、压力不大、外力作用时间不长的情况下,主要显示为弹性性质;但在温度高、压力大、作用力时间长的情况下,则显示出流变性质.对于持续数十秒的快速错动的地震发生过程,用弹性理论处理发震过程是恰当的,但对于持续数百年乃至上千年的孕震过程,岩石的流变性是必须考虑的问题(张国民,1987;尹祥础,郑天愉,1982;梅世蓉等,1993).  相似文献   

CHARACTERIZATION AND FORMATION MECHANISM OF THE CENTRAL UPLIFT OF THE QIANGTANG BASIN     

YIN Fuguang 《大地构造与成矿学(英文版)》2004,28(1):36-42

The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formation of an extension  相似文献