Decrepitation Thermometry and Compositions of Fluid Inclusions of the Damoqujia Gold Deposit,Jiaodong Gold Province,China:Implications for Metallogeny and Exploration   总被引：20，自引：0，他引：20  

Yang Liqiang  Deng Jun  Zhang Jing  Guo Chunying  Gao Bangfei  Gong Qingjie  Wang Qingfei  Jiang Shaoqing  Yu Haijun 《中国地质大学学报(英文版)》2008,19(4):378-390

The recently discovered Damoqujia (大磨曲家) gold deposit is a large shear zone-hosted gold deposit of disseminated sulphides located in the north of the Zhaoping (招平) fault zone, Jiaodong (胶东) gold province, China. In order to distinguish the temperature range of cluster inclusions from different mineralization stages and measure their compositions, 16 fluid inclusions and 5 isotopic geochemistry samples were collected for this study. Corresponding to different mineralization stages, the multirange peaks of quartz decrepitation temperature (250-270, 310-360 and 380-430℃(2) indicate that the activity of ore-forming fluids is characterized by multistage. The ore-forming fluids were predominantly of high-temperature fluid system (HTFS) by CO2-rich, and SO2-4-K type magmatic fluid during the early stage of mineralization and were subsequently affected by low-temperature fluid system (LTFS) of CH4-rich, and Cl--Na /Ca2 type meteoric fluid during the late stage of mineralization. Gold is transferred by Au-HS- complex in the HTFS, and Au-Cl- complex can be more important in the LTFS. The transition of fluids from deeper to shallow environments results in mixing between the HTFS and LTFS, which might be one of the most key reasons for gold precipitation and large-scale mineralization. The ore-forming fluids are characterized by high-temperature, strong-activity, and superimposed mineralization, so that there is a great probability of forming large and rich ore deposit in the Damoqujia gold deposit. The main bodies are preserved and extend toward deeper parts, thereby suggesting a great potential in future.  相似文献   

MOLECULE FOSSIL EVIDENCE FOR PALEOVEGETATION CHANGES IN THE CENTRAL OF CHINESE LOESS PLATEAU DURING 7～2Ma——ZHAOJIACHUAN PROFILE AS AN EXAMPLE     

Liu Weiguo  Zhang Pu  Sun Youbin  Huang Yongsong  Guo Zhengtang  An Zhisheng 《第四纪研究》2008,28(5)

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高放废物处置库天然类比及其有关的地球化学问题     

郭永海  王驹  王志明  刘淑芬  宗自华  周佳 《物探与化探》2008,32(5):574-577

介绍了高放废物处置库天然类比研究的主要内容,重点阐述了类比研究中涉及的地球化学问题,包括核素溶解度和化学形态研究、核素迁移速率研究、核素迁移影响因素研究,并总结相关问题研究取得的成果和认识.  相似文献   

Helium-argon isotopic tracing for the Pb-Zn-Ag polymetallic ore deposits in the central-south segment of the Da Hinggan Ling Range     

Baode Wang  Shuyin Niu  Aiqun Sun  Huabin Hu  Yaming Liu  Lijun Guo  Shuo Wang 《中国地球化学学报》2008,27(3):235-241

In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range, though some debates still exist on the metallogenesis and sources of ore-forming materials. Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids, and the first He and Ar isotope data have been obtained from the study region. ^3He/^4He ratios in 14 samples collected from 7 mining districts are 2.17×10^-6-12.52×10^-6, averaging 6.86×10^-6 and their R/Ra ratios are 1.56-9.01 Ra, averaging 4.37 Ra. By projecting the data points onto the ^3He-^4He concentrations diagram, all the points fall near the mantle helium area. The calculated mantle-source helium ratios are within the range of 19.58%-76.96%, with an average of 49.52%. Argon isotopic characteristics are close to those of mantle source, indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures.  相似文献   

The distribution and geological significance of carbazole compounds in Silurian paleo-pools of the Tarim Basin,Northwest China     

LIU Luofu HUO Hong GUO Yongqiang CHEN Lixin LI Shuangwen ZHAO Yande LI Yan WANG Ping CHEN Zhijun 《中国地球化学学报》2008,27(1):1-8

The results presented in this paper indicated that the carbazole-type compounds have high thermal stability and also show stability in oxidation and bio-degradation. This kind of compounds still has high concentrations and a complete distribution in the analyzed dry asphalt samples, showing that they are particularly useful in the study of hydrocarbon migration of the paleo-pools. The difference in the contents of nitrogen compounds in the Silurian dry asphalts from the Awati, Tabei and Tazhong areas is attributed to the difference in the extent of oxidation and （or） bio-degradation for the areas; the Awati and Tabei areas underwent relatively strong oxidation and bio-degradation. During the first stage of hydrocarbon pool formation in the Silurian system in the Tazhong and Tabei areas of the Tarim Basin （at the end of the Silurian period） and at the second stage in the Awati area （in Permian）, the hydrocarbons experienced a long-distance migration.  相似文献   

Simulation experiment on hydrocarbon generating potential of various source rocks on the northern margin of the Qaidam Basin,Qinghai, China     

Xin Li  Dongliang Wang  Baoquan Liu  Chunling Ren  Jianying Guo  Xuefeng Su  Jian Wang 《中国地球化学学报》2008,27(4):412-419

The northern margin of the Qaidam Basin is one of the main oil-gas exploration areas in western China, where source rocks are composed mostly of Middle and Lower Jurassic dark mud shale, carbargillite and coal. A large number of subsurface and outcrop samples differing in lithology with different types of organic matter were selected for resource evaluation, research and calculation. And among them, 13 samples were used for simulation experiment on hydrocarbon generating potential of various source rocks. At first, two kinds of heating modes were compared through simulation experiment, including single temperature-step heating and continual heating. Perhaps, the process of hydrocarbon generation and expulsion occurred naturally between a close system and an open system. In addition, the first heating mode was convenient, and all its reaction products were involved in the whole thermal evolution, and the final simulation experimental results were basically in consistency with the natural evolution trend Therefore, the first heating mode was adopted and the hydrocarbon yield of every sample was worked out. According to the type and lithology of organic matter and the hydrocarbon yield of samples for simulation experiment, hydrocarbon generation and expulsion mode with three kinds of lithology and five types of source rock has been established to provide the basis for hydrocarbon generation evaluation, research and resource calculation.  相似文献   

A framework of region-based spatial relations for non-overlapping features and its application in object based image analysis   总被引：2，自引：0，他引：2  

Yu Liu  Qinghua Guo  Maggi Kelly   《ISPRS Journal of Photogrammetry and Remote Sensing》2008,63(4):461-475

Object based image analysis (OBIA) is an approach increasingly used in classifying high spatial resolution remote sensing images. Object based image classifiers first segment an image into objects (or image segments), and then classify these objects based on their attributes and spatial relations. Numerous algorithms exist for the first step of the OBIA process, i.e. image segmentation. However, less research has been conducted on the object classification part of OBIA, in particular the spatial relations between objects that are commonly used to construct rules for classifying image objects and refining classification results. In this paper, we establish a context where objects are areal (not points or lines) and non-overlapping (we call this “single-valued” space), and propose a framework of binary spatial relations between segmented objects to aid in object classification. In this framework, scale-dependent “line-like objects” and “point-like objects” are identified from areal objects based on their shapes. Generally, disjoint and meet are the only two possible topological relations between two non-overlapping areal objects. However, a number of quasi- topological relations can be defined when the shapes of the objects involved are considered. Some of these relations are fuzzy and thus quantitatively defined. In addition, we define the concepts of line-like objects (e.g. roads) and point-like objects (e.g. wells), and develop the relations between two line-like objects or two point-like objects. For completeness, cardinal direction relations and distance relations are also introduced in the proposed context. Finally, we implement the framework to extract roads and moving vehicles from an aerial photo. The promising results suggest that our methods can be a valuable tool in defining rules for object based image analysis.  相似文献   

河北省白洋淀洼地环境地球化学物源判断   总被引：7，自引：1，他引：6  

张秀芝  郭海全  李宏亮  李建华 《地学前缘》2008,15(5)

河北省白洋淀洼地是一个大型天然平原洼地,在洼地的深、浅层土壤中均发现了以Cu、Pb、Zn、Cd为主的多变量地球化学异常。运用地球化学特征法、参考元素法及多元统计法,对深、浅层土壤Cu、Pb、Zn、Cd异常的性质和成因进行了判别。结果表明,深层土壤异常与特定的地球化学沉积环境有关,以自然地质作用成因为主,而浅层土壤异常具有典型的二元叠加特征,以人为源的输入为主。  相似文献   

Magnetic-field variations in the active region NOAA 10486 and their relationship to X-ray flares and coronal mass ejections     

O. V. Chumak  H. -Q. Zhang  J. Guo 《Astronomy Reports》2008,52(10):852-865

SOHO/MDI magnetograms are used to analyze the time variations in the magnetic parameters of the active region (AR) NOAA 10486, which was part of a large activity complex that passed over the solar disk from October 26 to 31, 2003, during solar cycle 23. The results are compared with X-ray flares in the AR and the parameters of coronal mass ejections associated with the AR. The time variations in the distributions of themagnetic-field strengths associated with the total magnetic flux (Fa), the flux imbalance between the northern and southern polarities (Im), the complexity of the field, as a measure of the mutual overlapping of the opposite polarities (Co), and the tilt angle of the magnetic axis (An) are considered. The time variations in the free energy accumulated in current sheets of ARs were traced using a parameter introduced for this purpose (Sh). The following results were obtained. First, the parameters Fa, Im, Co, An, and Sh quantitatively describe the current state of the AR and can be used to trace and analyze the dynamical evolution of its magnetic field. Second, variations in the magnetic-field-strength distributions and the mean values of Fa, Im, Co, An, and Sh are associated with flares and coronal mass ejections, and the variations have considerable amplitudes. Third, the parameter Sh characterizing the degree to which the magnetic field is non-potential in regions adjacent to the main neutral line increases before eruptive events, and is thus particular interest for monitoring the states of ARs in real time. Fourth, the magnetic field of the AR manifests a sort of quasi-elasticity, so that the field structure is restored after active events, on average, within 1–3 h.  相似文献   

一种基于Helmert方差分量估计的Vondrak滤波方法     

郭固良  曾凡河  周晓卫 《现代测绘》2008,31(1):11-12,22

从基于Helmert方差分量估计的Vondrak滤波方法(简称HVF法)的基本假设入手,介绍了HVF方法,该方法能够在未知拟合函数的情况下,通过自动选择合理的平滑因子控制数据平滑的程度,对时序数据序列进行合理平滑,最大限度的削弱数据序列中的随机误差,将信号与噪声合理分离.  相似文献