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Fluid inclusion studies were made on the basis of the geological data on the strata-bound ore de-posits of China including those of Pb,Zn,Au,Ag,Sb,U,Hg,W,quartz-crystal and sparry-calcite.An attempt was made to approach the model of formation for each type of ore depos-its by considering the material sources,the migration of fluids and the conditions of mineralization.It is found that ore-forming fluids (especially H2O)originate as heated underground water reacts with the wallrocks and dissolves Na^ ,Ca^2 ,K^ ,Cl^ ,HCl^- and Mg^2 .The ore fluids are mainly of NaCl-Ca-HCO3-H2O system with salinities ranging from 4to 14wt.%.NaCl equivalent and densities ranging from 0.9 to 1.0g/cm^3.It may be concluded that the deposits were formed at temperatures ranging from 150 to 250℃ under pressures from 300 to 1000 bars.Ore deposition may have been controlled by temperature and pressure or by the mixing among different fluids. 相似文献
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《Gondwana Research》2006,9(4):617-621
A laser fusion Ar-Ar technique applied on single crystals of kyanite from river sands of the Kitakami Mountain region of northeast Japan yielded ages of up to 16 Ga, more than three times the age of the earth. Although the age values are geologically meaningless, the ultra-high excess argon in kyanites is unique and hitherto unreported. We interpret this to be an artifact of ultra-high argon pressure derived from radiogenic argon in potassium-rich phases such as phengites during the Barrovian type retrogression of the ultra-high pressure rocks in this region. 相似文献
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地球中的流体和穿越层圈构造 总被引：2，自引：2，他引：0
地球中的流体是当前科学研究的重点。从地球科学的角度来说,流体应包括气体、液体（水和石油）、熔体和地球中受应力作用而移动的物体。在半经为6378 km的固体地球中可分为7个层圈。目前对地球内部流体的了解很少,为探索流体在各层圈中的成分,物理化学性质和分布,以现阶段对地球层圈和流体研究程度来看,其重点应放在地球中穿越层圈的构造部分和地壳。地球中穿越层圈的构造主要有三个:板块构造的俯冲带是由上到下的穿越层圈构造,向下俯冲的大洋岩石圈可以抵达地幔过渡带;大洋中脊的扩张引起的由下而上的穿越层圈构造,使岩石圈和地幔的熔流体从下向上运移;地幔柱引起的由下而上的穿越层圈构造,使地幔的熔流体从下向上迁移。通过对三个穿越层圈构造和地壳中流体的研究,可以得出地壳、岩石圈、上地幔、过渡带、下地幔和核幔边界层流体的种类和成分、流动和演化。这是至今为至能鉴定到地球中深部流体的方法。这四个方面的研究是当前地球中流体科学研究的重点,并对开展深部找矿有实际意义。 相似文献
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In this study,an electron microprobe analyzer(EMPA) was used to map the spatial distribution and the occurrence of invisible gold in pyrite from the Liulincha gold ore belt.EPMA data show that gold mainly occurs as submicroscopic-microscopic inclusions.From the contrast of the major guide elements of pyrite from the Liulincha gold ore belt and those from four hydrothermal-type gold deposits in the Jiaodong region,we can see the pyrites were formed in two stages:the pyrite from wall rock is mainly sedimentogenic,with simple structure;and the pyrite from ore body experienced early sedimentary process to late hydrothermal activity,the pyrite is regular in crystal form and exhibits fractured structure. 相似文献
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Organic Geochemistry of Sedimentary Rock-hosted Disseminated Gold Deposits in Southwestern Guizhou Province, China 总被引：2，自引：1，他引：1
Jayanta GUHA 《《地质学报》英文版》2005,79(1):120-133
Sedimentary rock-hosted disseminated gold (SRHDG) deposits in the Youjiang-Nanpanjiang Basin,southwestem Guizhou Province are commonly hosted by the same fold crests that commonly contain a remarkable amount of organic material. The total organic carbon (TOC) contents of the ores and host rocks are usually less than 1%. The reflectance of vitrinite and pyrobitumen in the ores and the host rocks ranges from 1.5% to 4.5%, often in the range of 2% to 3%. In the Lannigou deposit, the reflectance of vitrinite and pyrobitumen in the ores is usually somewhat higher than those within the host rocks, indicating a hydrothermal impact on the organic matter in the altered host rocks. On the contrary, the estimated maximum paleotemperatures of the Getang and Zimudang deposits are higher than the homogenization temperatures of the fluid inclusions in the ores, signifying that the organic matter maturation predated Au mineralization. No correlation between the organic matter contents and Au concentrations were recognized in the ores.However, the most striking observation is that there is a positive correlation between the $2 (a parameter of Rock-Eval analysis), Au and As contents of the ores in the Lannigou deposit. Organic matter maturation and migration is apparent from the TOC vs. HCI diagram. Furthermore, group analysis of the dichloromethane extractable organic component of the ores and host rocks shows that the maturation degree of the organic matter in the ores is slightly higher than that of the host rocks in the Lannigou gold deposit. However, the compositions of their alkanes, steranes and terpenes, which serve as biomarkers, are quite similar; this suggests that the organic matter found in the ores and host rocks has a common marine source. Organic matter probably contributed to the preconcentration of Au in the host rocks. Hydrocarbons in the system,on the other hand, clearly contributed to the emplacement of the gold mineralization through thermal sulfate reduction.Organic matter in the solution might have increased the potential of the hydrothermal solution to transport Au. 相似文献
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金矿床中金与黄铁矿和毒砂的关系 总被引：10，自引：4，他引：6
卡林型金矿中的金,以肉眼,甚至在显微镜下都看不到,因而称之为“不可见金”.经过金的物相分析,发现Au与毒砂、黄铁矿有关.进一步的问题是:Au在毒砂、黄铁矿中呈何状态分布,是呈微细的独立矿物?还是类质同象?是以化学键进入毒砂、黄铁矿的晶格?还是吸附在其表面?进一步的研究表明,世界上其他类型金矿,如浊积岩型金矿、造山带内太古代绿岩带金矿、变质金矿、与火成岩有关的金矿,甚至含金的块状硫化物矿床,其中的金除了以自然金(可见金)产出外,在黄铁矿、毒砂、辉锑矿、雄黄等硫化物中还含有不可见金.从不可见金到可见金,需经过热液蚀变作用,在高As条件下,温度和硫逸度的升高,可溶出不可见金,在温度下降和还原条件下,Au以可见金形式存在于蚀变环带中.这种从不可见金到可见金的转换过程,反映了Au、As、S以及Fe等元素的地球化学特征.金矿中的黄铁矿和毒砂具有相似的结构,包括在其原始生长的晶体中含有不可见金,并且在稍后的成矿阶段内形成赋存有可见金的蚀变环带.蚀变环带以As含量高为特征,并且,后期的可见金是沿裂隙或毒砂与黄铁矿的粒间分布.可见金是热液活化了矿物内的不可见金而形成的. 相似文献
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当前流体包裹体研究和应用概况 总被引：12，自引：7，他引：12
本文概要总结近年来流体包裹体研究和应用的发展情况，包括流体包裹体岩相学，PVTX研究，分析技术和应用等四个方面。岩相学方面的主要进展反映在“流体包裹体组合”概念的提出和应用。在PVTX研究方面，人工包裹体和热液金刚石压腔的应用极大地促进了我们对地质流体体系相特征的了解。各种分析技术不断涌现或改进，其中以Laser-Raman对气体成分和LA-ICP—MS对溶质成分的分析尤其有用。流体包裹体的应用领域一直以矿床学研究为主，当前和今后一段时间仍将如此。但是，流体包裹体在地球科学的其它领域，尤其是石油地质以及岩浆和地球内部过程的研究等方面，正得到越来越多的应用。 相似文献
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