西藏东南部嘉黎断裂新知   总被引：29，自引：1，他引：28       下载免费PDF全文

任金卫  沈军  曹忠权 《地震地质》2000,22(4):344-350

野外调查表明 ,西藏东南部的嘉黎断裂带从那曲到嘉黎由三段呈雁行排列 ,大致沿N60°W方向延伸 ,其东南段在波密附近向南转折 ,沿贡日嘎布曲向南南东过上察隅和下察隅后转为近南北向延入缅甸境内与什阶断裂相连。嘉黎断层全新世以来活动性不强 ,其第四纪以来的平均滑动速率约为 4mm/a。一个有趣的现象是 ,虽然总体上嘉黎断裂的新活动不强 ,但在局部与张性盆地相邻的地段表现出较强的活动性 ,在这些段上沿断裂发育晚第四纪地表破裂 ,横跨断层的冲沟和河流被错断 ,其晚第四纪以来的平均滑动速率达到 15mm/a。但是这种现象的存在只局限在盆地中 ,盆地以外则截然终止 ,不复存在。从上述事实看 ,嘉黎断裂的走滑活动似乎是伴随张性活动而产生的 ,在断层几何和活动特征上类似于横切大洋中脊的转换断  相似文献   

Rare Earth Element Geochemistry of Late Palaeozoic Coals in North China   总被引：7，自引：0，他引：7  

HUANG Wenhui  YANG Qi  TANG Dazhen China University of Geosciences  Xueyuan Rd.  Haidian District  Beijing TANG Xiuyi  ZHAO Zhigen Huainan Institute of Technology  Huainan  Anhui 《《地质学报》英文版》2000,74(1):74-83

Instrumental Neutron Activation Analysis (INAA) was done to determine the abundances of rare earth elements (REE) of 58 samples of Late Palaeozoic Carboniferous-Permian coals and related rocks in North China. Detailed study of REE geochemistry shows that the ∑REE of most coals studied in this paper is in a normal range between 30×10-6 and 80×10-6 with a mean of 56×10-6. The REE in the Taiyuan Formation in the northern part of North China are much richer than those in the southern part. This is due to the shorter distance to the source area in the north. Moreover, the IREE is in positive correlation to coal ash, especially closely related to the content of clay minerals <2μm in size. This reveals that most REE were carried by terrigenous clastic materials, especially fine clay minerals. In the coals the light REE (LREE) are much richer than the heavy REE (HREE), and the LREE/HREE ratio in coals generally varies from 2 to 8. The LREE/HREE ratio of high-ash, low-sulphur coals is higher than that of lo  相似文献   

Spatial and Temporal Distribution of Au and Pb-Zn Mineralization: Phenomenon, Mechanism and Implication   总被引：1，自引：0，他引：1  

WANG Dongbo  SHAO Shicai  XU Yong  LIU Guoping Beijing Institute of Geology for Mineral Resources  Beijing State Nonferrous Metals Industry Administration  Beijing 《《地质学报》英文版》2000,74(3):504-510

In the 1990s, some median-large gold deposits have been discovered in several lead-zinc metalloge-netic belts (e.g. the Qinling lead-zinc metallogenetic belt, Shanxi Province and Gansu Province and the Qingchengzi lead-zinc ore field, Liaoning Province) in China. Gold deposits and lead-zinc deposits spatially co-exist in the same tectonic setting; lead-zinc orebodies are commonly located below gold ore bodies. The host rocks of lead-zinc ore-bodies are conformably overlain by those of gold ore bodies. The age of gold mineralization is obviously younger than that of lead-zinc mineralization. Preliminary geochemical research has demonstrated the following: lead-zinc mineralization took place in a marine sedimentary-exhalative system, which had the characteristics of a high fluid/rock ratio, a high salinity and a high halide activity; meanwhile, most of gold was transported into the low-temperature hydrothermal plume and primarily enriched in sediments. During later (magmatism-) metamorphism-tectonism, gol  相似文献   

A Study of the Accompanying Relationships between Uranium and Oil     

LI Huaiyuan 《《地质学报》英文版》2000,74(3):595-601

It is not occasional that uranium deposits and oil accumulation occur in the same depression in the Erlian basin, Inner Mongolia. Some evidences show certain relations between uranium and oil in origin. This paper discusses and analyses the evidence for the relations between uranium deposits and oil and gas accumulation in terms of spatial distribution, geology, hydrochemistry and geochemistry. The paper also deals with the mechanism of the formation of uranium deposits and points out that it is of significance to use uranium as an indicator to search for oil and vice versa.  相似文献   

Biological and Molecular Geochemical Evidence for Dinoflagellate Ancestors in the Upper Sinian-Cambrian   总被引：5，自引：0，他引：5  

J.Mike MOLDOWAN 《《地质学报》英文版》2000,74(4):740-747

Dinoflagellates are single celled organisms that reflect the ecological conditions in modern oceans and lakes. Their earliest undisputed fossil record suggests that dinoflagellates originated from the Middle Triassic (c. 240 Ma ago). However, the presence of molecular biomarkers (dinosterane, 4α-methyl-24-ethylcholestane and tria-romatic dinosteroids) in rock extracts and coccoid dinoflagellate fossils from the upper Sinian to Cambrian of the Tarim basin confirms the hypothesis that dinoflagellates have an ancient origin, and predate the oldest undisputed dinoflagellate fossils at least by 300 Ma, as early as the late Sinian-Cambrian.  相似文献   

Classification of Mineral Resources Associated and Accompanied with Coal Measures     

YUAN Guotai  HUANG Kaifen China National Administration of Coal Geology  Zhuozhou  Hebei 《《地质学报》英文版》2000,74(3):717-720

The paper discusses the concept of mineral resources associated with coal measures. A rational and scientific classification of such mineral resources becomes more necessary with the development of science and technology. A classification scheme is proposed based on compositions and physical properties and the utilization of these associated minerals.  相似文献   

Land use and land cover change in Liaocheng Prefecture of China     

Received date: --  Revised date: -- Foundation item: Under the auspices of the National Natural Science Foundation of China 《地理学报(英文版)》2000,(3)

1 Introduction1.1 Introduction to Liaocheng PrefectureLiaocheng Prefecture lies in northwest of Shandong Province and slightly north to the center of the Huang-Huai-Hai Plain with latitudes between 35(47'N and 37(02'N and longitudes between 115(16'E and 116(32'E. Administratively, it consists of two cities (Liaocheng and Linqing) and six counties (Yanggu, Shenxian, Chiping, Dong'e, Guanxian and Gaotang). It covers a total area of 8590 km2 with a maximum distance of 114 km from eas…  相似文献   

Application of the Load/Unload Response Ratio Theory to Predictions of Moderate Earthquakes (7.0>M≥6.0)     

Chen Xuezhong  Yin XiangchuInstitute of Geophysics  SSB  Beijing ChinaCenter for Analysis  Prediction  SSB  Beijing China 《中国地震研究》1995,(3)

The variation in load/unload response ratio before some moderate earthquakes is analyzed based on the theory of the load/unload response ratio.The results show that the load-unload response ratio increases noticeably before moderate earthquakes,and there are three kinds of patterns in which the load/unload response ratio varies and the duration of noticeable increase in load/unload response ratio ranges from half a year to two years.  相似文献   

Application of Dempster-Shafer theory in mineral resource potential mapping     

CHEN Yong-liang  WU Wei  LI Xue-bin Mineral Resource Prediction Institute of Comprehensive Information  Jilin University  Changchun  Jilin  China Northeastern Geography  Agricultural Ecology Institute of Chinese Academy of Sciences  Changchun  Jilin  China Design  Research Institute of Urban  Rural Planning of Changchun  Changchun  Jilin  China 《东北亚地学研究》2005,(Z1)

The Dempster-Shafer theory has been successfully applied to mineral resource potential mapping in G1S environmental. In this applied form, basic probability assignment and combined basic probability assignment are applied to measuring map pattern and map pattern combination, respectively; and the environment composed of the only two singleton sets (deposit set and non-deposit set), is used for expressing the entire map area. For a subarea in which the certain map pattern combination exists, the combined basic probability assignment corresponding to the map pattern combination existing in this subarea, expresses the belief of inferring the subarea belonging to the deposit set from the evidence that the corresponding map pattern combination existing in the subarea. Thus, it may be served as a statistical index measuring the relative mineral resource potentials of the subarea. And it may be determined like 1) dividing the map area into a series of small equal-sized grid cells and then select the training sample set composed of the well-known grid cells or the entire grid cells; 2) estimating the basic probability assignments corresponding to each map pattern from the training sample set; 3) determining the map pattern combination existing in each cell, and then appling the Dempster's Rule of Combination to integrating the all basic probability assignments corresponding to the map patterns existing in the cell into the combined basic probability assignment. Mineral resource potential mapping with the Dempster-Shafer theory is demonstrated on a case study to select mineral resource targets. The experimental results manifest that the model can be compared with the weights of evidence model in the effectiveness of mineral resource target selection.  相似文献   

蛇绿岩建造非金属矿床成矿系列初步探讨     

鱼海麟 《青海国土经略》1995,(2)

我国蛇绿岩分布广泛。蛇绿岩中有着成因上和时空上紧密联系的一系列非金属矿床,它们构成了蛇绿岩建造非金属矿床成矿系列。这一成矿系列中的主要非金属矿有橄榄岩、玄武岩、蛇纹岩、石棉、滑石、玉石类等等,主要的成矿作用有岩浆作用、接触变质作用、交代蚀变作用等。其成矿作用和矿床分布模式有明显规律,这些规律对于地质勘查、资源开发等都具有重要的意义。  相似文献