山东沂水麻粒岩杂岩中的变质流体及地质意义   总被引：2，自引：0，他引：2  

徐惠芬  沈其韩 《华北地质矿产杂志》1995,10(2):154-166

山东沂水麻粒岩杂岩中含有大量高密度富ＣＯ＿２流体包裹体，伴随有ＣＯ＿２－Ｈ２Ｏ，ＣＯ＿２±Ｎ＿２±ｃＨ＿４的包裹体。对这些包裹体的产状、分布和组成等特征进行了详细的岩相学研究，并选择有代表性样品进行了显微测温和激光拉曼探针分析。结合本区地质和岩石学研究成果确定沂水麻粒岩杂岩峰期变质温度为８００℃，压力为０．７５ＧＰａ。对变质流体组成、演化及其成岩意义也进行了讨论。  相似文献   

滇黔桂三角区微细浸染型金矿床成矿热液一种可能的演化途径:年代学证据   总被引：24，自引：1，他引：24  

胡瑞忠  苏文超  毕献武  李泽琴 《矿物学报》1995,(2)

本文主要根据年代学资料和金活化迁移的地球化学属性，探讨了滇黔桂三角区微细浸染型金矿床成矿热液的演化途径。多种定年方法揭示，该区金成矿初始流体（古流体）的年龄为260Ma左右；金成矿年龄约为140～75Ma。考虑到该区燕山晚期岩浆岩富含Cl，本文认为古流体（260～140Ma）向成矿流体（140～75Ma）的转化，可能主要是通过燕山晚期岩浆活动产生的富氯流体加入原已存在的贫氯古流体，从而使这种新的混合流体具有浸取金的能力来实现的。  相似文献   

Deep crustal growth of quartz, kyanite and garnet into large-aperture, fluid-filled fractures, north-eastern Connecticut, USA   总被引：1，自引：1，他引：1  

J. J. AGUE 《Journal of Metamorphic Geology》1995,13(2):299-314

Abstract A petrographic and petrological analysis of exceptionally well-preserved hydrothermal veins from the Merrimack synclinorium, north-eastern Connecticut, has been carried out in order to place new field-based constraints on fracture aperture dimensions and porosity in the lower continental crust. The veins preserve substantial open space today in outcrop, and contain mineral assemblages including subhedral to euhedral crystals of quartz, kyanite and almandine-rich garnet. Textural evidence indicates unequivocally that the vein minerals grew into macroscopic (mm- to cm-scale) open space between the vein walls. The veins are interpreted to have been large-aperture fractures along which significant advective fluid infiltration and chemical reaction occurred. The porosity of the rock mass due to open space between fracture walls today is c . 0.3%, but it could have been as large as several percent when the flow system was active. Quantitative thermobarometry results from vein mineral assemblages indicate that the fractures formed at pressures and corresponding crustal depths of c. 0.8 GPa and c. 30km, and temperatures of 550–600° C. The depth of fracture formation corresponds to published estimates of the maximum burial depth of the Merrimack synclinorium during the Acadian orogeny. The formation of large-aperture fractures could increase significantly the transient permeability of the deep crust, and therefore influence metamorphic heat and mass transfer.  相似文献   

Experimental diffusion of hydrogen into synthetic fluid inclusions in quartz   总被引：2，自引：0，他引：2  

D. L. HALL  S. M. STERNER 《Journal of Metamorphic Geology》1995,13(3):345-355

Abstract Quartz-hosted, synthetic CO₂-H₂O fluid inclusions behave as open systems with respect to diffusional transfer of hydrogen during laboratory-simulated metamorphic re-equilibration at 650, 750 and 825°C and 1.5 kbar total pressure with f_O2 defined by the C-CH₄ buffer. Microthermometry and Raman spectroscopy show that the initial CO₂-H₂O inclusions become CO₂-CH₄-H₂-H_2O
inclusions after diffusive influx of hydrogen from the reducing confining medium. Measurable changes are observed in inclusion compositions after only 15 days of re-equilibration, implying significant hydrogen mobility at still lower temperatures over geological time spans. Results of synthetic inclusion re-equilibrium experiments have profound implications for the interpretation of natural fluid-inclusion data; failure to account for potential hydrogen migration in inclusions from high-temperature geological environments may lead to erroneous estimates of P-T, and/or the compositions of metamorphic fluids.  相似文献   

三相泡沫钻井液流变特性研究          下载免费PDF全文

吴飞  冯钢 《探矿工程》1995,(2):39-40

三相泡沫钻进液流变模式可通过灰色关联分析法进行优选，卡森模式是描述该钻井液流变特性的主要模式，该钻井液表观粘度高，工应力较大，剪切稀释特性强，流变参数主要受气比和基浆性能影响。  相似文献   

浙江遂昌地区金矿床矿物包裹体研究     

张亚雄 《大地构造与成矿学》1995,19(3):274-280

对浙江遂昌地区所发现的金（银）矿床之矿物包裹体研究表明，其均一化温度多集中在１４０～２６０℃，成矿压力（０．２～０．６）×１０２ＭＰａ，气液比在５％～２７％。成矿流体为液态，矿液中主要有Ａｕ，Ａｇ，Ｃｕ，Ｐｂ，Ｚｎ，Ｂｉ，Ｋ，Ｎａ，Ｃａ，Ｓｉ．Ｍｇ，Ｈ２Ｏ，ＣＯ２．Ｃｌ，Ｆ，Ｓ，Ｍｎ，Ｌｉ．Ｔｉ，Ｃｒ，Ｃｏ，Ｎｉ等组分。成矿时的含矿流体呈弱酸性─中性（ｐＨ４．５６～５．１４），盐度较高（ＮａＣｌ（２０～３２）ｗＢ％）．根据这些特征，并综合其产出的大地构造环境及成矿地质条件，认为该区所产出的金（银）矿床在成因上属地洼型火山─次火山中（─低）温热液矿床。  相似文献   

成矿过程流体地球化学模拟及其矿床学意义：以江西银山矿床为例   总被引：7，自引：1，他引：7       下载免费PDF全文

陈繁荣 《地质论评》1995,41(1):42-47

本文将银山成矿体系为富含Ｈ２Ｓ，ＣＯ２的ＮａＣｌ体系，对Ｃｕ，Ｐｂ，Ｚｎ，Ａｇ和Ａｕ等金属元素在该体系降温过程中的地球化学行为和银山矿床的成矿过程进行计算机数字模拟，并与沸腾降温体系进行对比，证明了成矿体系地球化学演化对金属元素的迁移与沉淀具有得要影响。成矿硫体地球化学模拟在矿床成因，深部成矿预测和区域成矿规律研究中具有重要意义。  相似文献   

福建省西部大地热流值   总被引：2，自引：0，他引：2       下载免费PDF全文

熊亮萍  胡圣标 《地质科学》1993,28(1):96-101

根据福建省西部53个钻孔的实测地温数据和300多块岩石样品的实测热导率数据,计算了29个大地热流值,说明福建西部热流的平均值为74mW/m²,相当于中新生代活动区的热流值。  相似文献   

Multi-layer Tectonic Model for Intraplate Deformation and Plastic-Flow Network in the Asian Continental Lithosphere   总被引：5，自引：0，他引：5  

Wang Shengzu Institute of Geology  State Seismological Bureau  Beijing Liu Linqun 《《地质学报》英文版》1993,67(3)

In a large area of the east—central Asian continent there is a unified seismic network system composed of two families of large—seismic belts that intersect conjugately. Such a seismic network in the middle—upper crust is actually a response to the plastic flow network in the lower lithosphere including the lower crust and lithospheric mantle. The existence of the unified plastic flow system confirms that the driving force for intraplate tectonic deformation results mainly from the compression of the India plate, while the long-range transmission of the force is carried out chiefly by means of plastic flow. The plastic flow network has a control over the intraplate tectonic deformation.  相似文献   

贵州早二叠世海相碳酸盐岩稳定同位素组成与玄武岩浆喷发热事件的关系   总被引：1，自引：0，他引：1  

田景春 《矿物岩石》1993,13(2):67-70

本文详细讨论了贵州织金地区早二叠世第一旋回海底喷发玄武岩浆对海相碳酸盐岩的碳、氧、锶同位素组成的影响,这主要表现为玄武岩浆喷发热事件导致了碳酸盐岩的δ~(1(?))C、δ~(18)O及~(87)Sr/~(86)Sr值的明显下降。  相似文献