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Zhen S.-M.,China University of Geosciences | Zhu X.-Y.,Beijing Institute of Geology and Mineral Resources | Du Z.-Z.,China University of Geosciences | Gong X.-D.,China University of Geosciences | And 3 more authors.
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2012

The Xianrenyan pluton is located in the south of Shuikoushan ore field, Hunan Province. There develops Au, Cu, Mo and Zn mineralization in inner and outer contact zones of the pluton, which shows the colse relationship between the pluton and the metallic mineralization. Zircon LA-MC-ICP-MS U-Pb age of the monzonite suggests a weighted mean age of (156.09±0.46) Ma (MSWD=1.4) which implies that the pluton was emplaced in Early Yanshanian period. The in-situ Hf isotopic analysis reveals 176Hf/177Hf ratios in the zircon range from 0.282243 to 0.282904, and εHf(t) from -15.55 to 7.87 (with peak value around -10), and the two stage Hf model ages(TDM2) from 703 Ma to 2188 Ma(with peak value around 1800 Ma), which indicates that parental magma of the pluton was derived from the mixed sources of the lower crust and mantle. Based on the geochemistry of the rocks, it can be concluded that the monzonite was mainly resulted from remelting of the Mesoproterozoic basement rocks and formed in Middle and Late Jurassic when the crust was in an extension-thinning geodynamic setting. In addition, the authors compare and analyze the lithogeochemical characteristics of the Xianrenyan pluton and the Shuikoushan stock. The fact that the Xianrenyan pluton has a weaker differentiation than the Shuikoushan pluton gives the reason for its unfavorable gold mineralization.


Zhang Q.,CAS Institute of Geology and Geophysics | Jin W.,CAS Institute of Geology and Geophysics | Li C.,Tianjin Center | Wang J.,Lanzhou University | And 3 more authors.
Geotectonica et Metallogenia | Year: 2015

It is of crucial important to identify the undiscovered intrusions in hydrothermal deposit prospecting. There are lots of effective methods to identify undiscovered intrusions, such as magnetic, electric, and gravitational methods. However, the vitrinite reflectance method for the geothermal indicator is a direct and simple method. Magmatic emplacement is bound to form a thermal field around, and form a temperature gradient field with the distance of magma and superimposed on the geothermal field. Therefore, we can find undiscovered intrusions through analysis of the variation of thermal field. If we know the heat transfer parameters of magma and surrounding rocks, we even can quantitatively determine the depth, the location and the scale of the undiscovered intrusion. The vitrinite reflectance (expressed as a Ro) method commonly used in coal and petroleum geology is a simple, economic, and effective method to identify undiscovered intrusion. The effective distance of the method is around a few meters to a few kilometers, depending on the size, composition, and depth of different intrusion. Regardless of the new and old mining area, you can try this method so long as there is post-Silurian mud rock. This method applies to the surface can also be applied to drilling. For old mining area, there are the research data for three dimension images, for new ones, the depth of Ro variation should be noted in order to guide the prospecting work in time. The authors argue that the intrusion is commonly associated with the fluid flow in the mining area. If Ro anomalies (Ro>2%) are found in the mining area, attention should be paid to the possibility of undiscovered intrusion and the accompanying mineralization in geological expectations. The authors hope that the introduction of this method, combining with the characteristics of hydrothermal ore deposit to the study of ore mineralization, will carve out a new application and make new progress in the deep prospecting. © 2015, Science Press. All right reserved.


Zhu X.-Y.,Beijing Institute of Geology and Mineral Resources | Zhu X.-Y.,Sinotech Mineral Exploration Co. | Wang J.-B.,Beijing Institute of Geology and Mineral Resources | Wang J.-B.,Sinotech Mineral Exploration Co. | And 5 more authors.
Geology in China | Year: 2012

The early Yanshanian granites related to tungsten and tin deposits in Nanling region have been considered to be biotite granite, monzogranite, albite granite etc. However, microscope and electron microprobe analyzes of the granite related to tungsten mineralization in Yaogangxian, Shizhuyuan, Xitian, Dengfuxian, Limu and Meiziwo show that all the feldspars of the granite consist of K-feldspar and albite (An<5), which suggests that the name should be alkali feldspar granite. The albite of greisen inclusions in the alkali feldspar shows the character An<3. There is no obvious vertical regular variation or zoning of the compositions of the albite and granite within the depth range of 1000m. On the contrary, the plagioclases of the granite inclusions (xenoliths), some granite porphyry dykes, giant batholiths, and Triassic and Paleozoic monzogranite or granodiorite have a wide range of An value of 0∼93, belonging to oligoclase, andesine or even basic plagioclase. The alkali-feldspar granite that contains two kinds of alkali feldspar was usually formed from the rich -volatile (Li -F) magma, with the extensive development of liquid immiscibility at the top of the granite, which caused the enrichment and mineralization of W, Sn, Bi, Mo in the hydrothermal-magma. The An value of the albite in alkali-feldspar granite could be used as an indicator for evaluating granite in search for W-Sn mineralization, because the value is obvious lower than that of barren granite.


He P.,China University of Geosciences | Yan G.-S.,Development and Research Center | Zhu X.-Y.,Beijing Institute of Geology and Mineral Resources | Zhang Z.-Y.,Beijing Institute of Geology and Mineral Resources | And 7 more authors.
Geology in China | Year: 2013

The fluid inclusions in the Saishitang Cu deposit can be classified into liquid-rich two-phase, gas-rich two-phase and daughter mineral-bearing polyphase types. According to studies of petrography, microthermometry and laser Raman spectrographic analyses of fluid inclusions in garnet and diopside from skarn and sulfide-rich quartz veins, the fluid inclusion homogenization temperatures and salinities of the early skarn stage vary in the range of 436t-562° C and 34 %-45%wt%NaCl eqv. respectively, indicating that the fluid is dominated by magmatic water characterized by high temperature and high salinity; the fluid inclusion homogenization temperatures and salinities of the retrogressive metamorphic stage vary in the range of 322° C-419° C and 15%-39%wt%NaCl eqv. Respectively; the fluid inclusion homogenization temperatures and salinities of the sulfide stage vary in the range of 235° C-366° C and 5%-36%wt%NaCl eqv. respectively. Laser Raman spectrographic analyses show that the gas phase components of fluid inclusions are mainly composed of CH4, FLS, CO2 and H2O, and the ore-forming fluids belong to the NaCl-H2O-CH4-H2S-CO2 system. The boiling event of ore-forming fluid occurred at temperatures of 290° C ∼ 360° C, resulting in the formation of massive metal sulfides. The fluid boiling was favorable for the formation of the Saishitang Cu deposit.


Zhang C.-L.,Nanjing Institute of Geology and Mineral Resources | Zhou G.,No.4 Geological Party | Wang H.-Y.,Nanjing Institute of Geology and Mineral Resources | Dong Y.-G.,Nanjing Institute of Geology and Mineral Resources | Ding R.-F.,Beijing Institute of Geology and Mineral Resources
Geological Bulletin of China | Year: 2010

A comprehensive analysis on the reported geological, geochronological and geochemical data of the Permian basaltic rocks in Tarim and the western section of the Central Asian orogenic belt (CAOB) indicates that the volume, petrography and their peaking activity at 275 Ma are correlated with those characteristics of other large igneous provinces (LIPs) in the world and we termed it as Bachu LIP. Elements and Sr-Nd isotopic compositions of the basalts in Tarim suggest that they may originate from partial melting of a long-term enriched lithospheric mantle at 60-80 km depth, while the mafic dykes and ultramafic-mafic intrusions in Tarim most possibly originated from asthospheric mantle (OIB-like). On the other hand, the basaltic rocks from the CAOB predominantly originated from partial melting of a subduction-released fluid (and/or melts) metasomatized lithospheric mantle involved with variable OIB-like basaltic magma addition, e.g., the high-Ti series basaltic rocks in southern Altaid and Eastern Tianshan areas. Thus based on geochemical data of major and trace elements, two different mantle domains can be divided within Bachu LIP, i.e., a long-term enriched Tarim domain and a subduction-metasomatized depleted CAOB domain. These two mantle domains have different metalogenesis types, i.e., the metalogenesis in Tarim is dominated by V-Ti magnetite mineralization, while in CAOB, dominated by Cu-Ni-PGE sulphide and co-genesis of Cu-Ni-PGE sulphide and V-Ti magnetite mineralization. The metallgenetic difference between in Tarim and in the western section of the CAOB is concurrent with the two different mantle domains. By integrating geological, geochronlogical, metallgenetic and geochemical data, we conclude that the formation of Bachu LIP is closely linked with a Permian mantle plume, which we term it as Bachu plume.


Yang Z.,Beijing Institute of Geology and Mineral Resources | Yang Z.,Donia Resources Co. | Yang Z.,Central South University | Zhang W.,Donia Resources Co. | And 3 more authors.
Chinese Journal of Geochemistry | Year: 2012

The Sipu region of North Guangxi is located in the southwest of the "Jiangnan Ancient Land", where there are developed the oldest stratum in southern China, the Proterozoic Sipu Group, and there are also largely exposed mafic intrusive rocks, mafic volcanic rocks and copper-nickel sulfide deposits. Both mafic intrusive rocks and volcanic rocks are rich in MgO (6. 52%-26. 39%), but poor in K 2O (0. 05%-1. 00%) and TiO 2 (0. 33%-0. 89%). They are also rich in trace elements such as Rb and Ba while poor in Ta, Nb and the like. Both of them have medium contents of rare-earth elements, 30. 26×10 -6-126. 71×10 -6, in which LREEs are slightly rich with Σ LREE/Σ HREE of 1. 35-2. 46, δEu 0. 79-1. 33, displaying weak or no δEu anomaly, with the same geochemical features. The right-inclined distribution patterns and the features show that magma would be formed at the comagmatic undiagenetic stage. All studies show that mafic intrusive rocks and volcanic rocks are the products of the same source region evolving in different stages and times. The copper-nickel sulfide deposits are characterized by liquation, crystallization and fractionation of mafic rocks, and have some interrelations with mafic intrusive rocks and volcanic rocks with respect to magmatic genesis. © 2012 Science Press, Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg.


Zhu X.,Beijing Institute of Geology and Mineral Resources | Zhu X.,Sinotech Mineral Exploration Co. | Wang J.,Beijing Institute of Geology and Mineral Resources | Wang J.,Sinotech Mineral Exploration Co. | And 2 more authors.
Yanshi Xuebao/Acta Petrologica Sinica | Year: 2015

Shizhuyuan large-scale skarn type tungsten and tin polymetallic ore deposit is located at Chenzhou County, Hunan Province, which occurred in the southern margin of the Qianlishan alkali feldspar granite body. The stockwork in skarn includes different types of veins, mostly alkali metamorphic vein (AMV), a few granite vein and greisen veins. The early stage AMV consists of granite vein in the central part, and K-feldspar-fluorite-wolframite in the margins, with garnet-diopside skarn alteration around the vein. The late stage AMV consists of K-feldspar, fluorite, minor actinolite, epidote, magnetite, scheelite, molybdenite, and bismuthinite. The AMV occurs only in the skarn and the skarnization marble, but is lack in the granite. The contents of CaO, TiO2, W, Bi, Mo, Cu, Pb, Zn, Sr and Ba show an increase trend from the granite, granite vein, AMV, to skarn, which may indicate an enrichment of ore materials from the magma to hydrothermal fluids. Evidence from the structure of granite vein in the center and the K-feldspar-fluorite in the margins, together with occurrence of melt or melt-fluid inclusions in the AMV indicate that the veins may have formed from a unique fluid transition from magma to hydrothermal. The evolution of this fluid is continuous from magmatic to hydrothermal process, and the mineralization started before the magma fully consolidation. We suggest the following mineralization model: Firstly, the pegmatite, massive greisen and banded wollastone-garnet skarn formed in the top and outboard of the granite in the latest magmatic stage; then in the prograde stage after widespread hydrothermal-brecciation, magma or the magma-hydrothermal transition fluid flow along the fractures of the carbonate rocks, which formed the stockwork mineralization and cause alteration of K-feldspar and garnet-diopside skarn. In the retrograde stage after magma consolidation, the mineral assemblage includes actinolite, magnetite, scheelite, molybdenum, and bismuth sulfides. In the latest sulfide stage, the temperature and fluid salinity decreased further on, and the Pb-Zn sulfides precipitate in the carbonate rocks outside the skarn. © 2015, Science Press. All rights reserved.


Qi F.-Y.,China University of Geosciences | Zhang Z.,China University of Geosciences | Zhu X.-Y.,Beijing Institute of Geology and Mineral Resources | Li Y.-S.,China University of Geosciences | And 4 more authors.
Geology in China | Year: 2012

The Hangshaping large-size W-Mo polymetallic ore deposit lies in the Nanling metallogenic belt. The authros chose the skarn as well as wall rocks (limestone and marble)and ?granite porphyry related to the skarn to conduct component analysis. The result shows that the major elements (Fe, Al, Mg and Si) migrated between the granite porphyry and the skarn, and the content of SiO 2 shows linear descending relationship with the content of MgO, MnO, CaO and Fe 2O 3+FeO in the skarn. The skarn is enriched in LREE and depleted in HREE, with obvious Eu negative anomalies. The granite porphyry has the same REE distribution patterns as the skarn. The precise Re-Os dating of the molybdenite from skarn-type ore yielded an ore-forming age of 158.4±1.3 Ma. which is the same as the age of the granite porphyry, suggesting their relationship in petrogenesis. The poorlydeveloped Ce anomalies in skarn rocks imply that the fluids for the formation of skarn were mainly derived from the magma and mixed with meteoric water. Combined with the geochemical characteristics of different rocks, intense differentiation of LREE and HREE and Eu negative anomalies, the authors infer that the skarn in the Huangshaping ore deposit was formed by fluid metasomatism.


Zhu X.-Y.,Beijing Institute of Geology and Mineral Resources | Wang Y.-L.,China Nonferrous Metals Resource Geological Survey | Cheng X.-Y.,Beijing Institute of Geology and Mineral Resources | Li S.-T.,China Nonferrous Metals Resource Geological Survey
Geology in China | Year: 2015

The steeply-dipping wolframite-quartz veins occur on both sides of the top contact zone of early Yanshanian granite, extending about <1000 m in the granite and about <500 m in sediments within the Yaogangxian tungsten deposit of Hunan Province. The sedimentary rocks overlying the granite consist of Precambrian metamorphic sandstone, Devonian sandstones and Triassic carbonaceous siltstone. Arsenopyrite topaz rocks (layers)occur along the sandstone overlying the Triassic-Devonian unconformity, and the tungsten-bearing quartz vein under the rocks (layers) is about 0.3 m in width. The studies of geology and geochemistry show that arsenopyrite-topaz rock mainly originally consists of quartz sandstone, with strong silicification, accompanied by arsenopyrite, topaz, muscovite and some other minerals, suggesting an altered rock. The rocks rich in Si, F, B and ore-forming elements such as W, Bi and Mo are similar to features of quartz veins. The fluid of alteration is the same as ore-forming fluid of quartz vein. The vertical zoning of the Yaogangxian tungsten deposit is different from the "five floor model" of wolframite-quartz veins. There are not veinlet and linear vein zones at the top of the model, but the arsenopyrite-topaz rock layer directly and gently dips over the steeply dipping quartz wide vein(0.3 m). A new metallogenic model for the tungsten bearing quartz vein deposit is suggested in this paper, i.e., "layer in the upper part and vein in the lower part". This model is of significance for the exploration of vein-type tungsten deposits, i.e., under the strongly silicified bedding alteration rocks with arsenopyrite, topaz and muscovite, there might occur steeply dipping wolframite-quartz veins.


Zhang Q.,Chinese Academy of Sciences | Zhang Q.,State Key Laboratory of Lithospheric Evolution | Mei Y.,Beijing Institute of Geology and Mineral Resources | Wang J.,Lanzhou University | And 5 more authors.
Scientia Geologica Sinica | Year: 2016

Metallogenic assemblage related to magma thermal field is a new concept related to the distribution of temperature gradient of magma thermal field. In the period of magmatic activity concentration range, all of the deposits are formed and influenced by magma thermal field, regardless of the genesis and types of ore deposits, all belong to a metallogenic assemblage. It includes magmatic hydrothermal deposit, sedimentary deposits superimposed by the magma thermal field, metamorphic deposits superimposed by the magma thermal field, energy deposits superimposed by the magma thermal field and hot spring deposits. Metallogenic assemblage related to magma thermal field links metallization with nonmetallic mineralization, organic mineralization with inorganic mineralization, hydrothermal mineralization with sedimentary mineralization, hydrothermal mineralization with metamorphic mineralization, metallization with energy metallization. There are two kinds of distribution of the metallogenic assemblage trend, one is from high to low temperatures in longitudinal sections, such as W-Sn-Pb-Zn combination, Sn-Cu combination; anther one is composed of different minerals metallogenic combination in transverse sections, such as W-Sn-graphite combination, Au-Cu-coal combination, Pb-Zn-coal combination, oil-gas-coal-U combination. Metallogenic assemblage emphasizes comprehensive prospecting. In prospecting, in addition to pay attention to the main mineral prospecting, we should also pay attention to other minerals and mineral prospecting. Looking for metal deposits, we should pay attention to the nonmetallic deposits, sedimentary superimposed deposit, metamorphic deposits as well as the possibility of energy mineral deposits. Looking for high temperature metal deposits, we should pay attention to the possibility of other minerals accompanied by high temperature mineralization, the possibility of low temperature metal deposit mineralization, the possibility of other mineral accompanied by low temperature mineralization. Around the magma thermal field, looking for all possible deposits is our own duty. © 2016, Science Press. All right reserved.

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