The Wangjiazhuang Cu(-Mo)deposit,located within the Zouping volcanic basin in western Shandong Province,China,is unique in this area for having an economic value.In order to expound the metallogenetic characteristics ...The Wangjiazhuang Cu(-Mo)deposit,located within the Zouping volcanic basin in western Shandong Province,China,is unique in this area for having an economic value.In order to expound the metallogenetic characteristics of this porphyry-like hydrothermal deposit,a detailed fluid inclusion study has been conducted,employing the techniques of representative sampling,fluid inclusion petrography,microthermometry,Raman spectroscopy,LA-ICP-MS analysis of single fluid inclusions,as well as cathode fluorescence spectrometer analysis of host mineral quartz.The deposit contains mainly two types of orebodies,i.e.veinlet-dissemination-stockwork orebodies in the K-Si alteration zone and pegmatiticquartz sulfide veins above them.In addition,minor breccia ore occurs locally.Four types of fluid inclusions in the deposit and altered quartz monzonite are identified:L-type one-or two-phase aqueous inclusions,V-type vapor-rich inclusions with V/L ratios greater than 50%-90%,D-type multiphase fluid inclusions containing daughter minerals or solids and S-type silicate-bearing fluid inclusions containing mainly muscovite and biotite.Ore petrography and fluid inclusion study has revealed a three-stage mineralization process,driven by magmatic-hydrothermal fluid activity,as follows.Initially,a hydrothermal fluid,separated from the parent magma,infiltrated into the quartz monzonite,resulting in its extensive K-Si alteration,as indicated by silicate-bearing fluid inclusions trapped in altered quartz monzonite.This is followed by the early mineralization,the formation of quartz veinlets and dissemination-stockwork ores.During the main mineralization stage,due to the participation and mixing of meteoric groundwater with magmatic-sourced hydrothermal fluid,the cooling and phase separation caused deposition of metals from the hydrothermal fluids.As a result,the pegmatitic-quartz sulfide-vein ores formed.In the late mineralization stage,decreasing fluid salinity led to the formation of L-type aqueous inclusions and chalcopyrite-sulfosalt ore.Coexistence of V-type and D-type inclusions and their similar homogenization temperatures with different homogenization modes suggest that phase separation or boiling of the ore-forming fluids took place during the early and the main mineralization stages.The formation P-T conditions of S-type inclusions and the early and the main mineralization stages were estimated as ca.156-182 MPa and 450-650℃,350-450℃,18-35 MPa and 280-380℃,8-15 MPa,respectively,based on the microthermometric data of the fluid inclusions formed at the individual stages.展开更多
This paper discusses the enrichment and depletion regularities for porphyry coppermolybdenum ore deposits in different regions and varied deposit genetic types in the same area, taking three porphyry copper-molybdenum...This paper discusses the enrichment and depletion regularities for porphyry coppermolybdenum ore deposits in different regions and varied deposit genetic types in the same area, taking three porphyry copper-molybdenum ore deposits （i.e., the Chengmenshan in Jiangxi, Wunugetushan in Inner Mongolia, Baishantang in Gansu） and two copper deposits in Gansu Province （the Huitongshan skarn deposit and Gongpoquan composite deposit） as case studies. The results show that porphyry Cu-Mo deposits or skarn copper deposits include both enrichment of the ore-forming elements and associated elements, and depletion of some lithophile dispersed elements, rare earth elements （REE） and some major elements. And the depleted elements vary with deposits, having generality and their own features. On a deposit scale, the positive anomalies of enriched elements and negative anomalies of depleted elements follow in a sequence to comprise regular anomaly models of spatial structures. The exploration in the Tongchang deposit in Jiangxi and Huitongshan deposit in Gansu suggests that anomaly models play a key role in the identification of mineral occurrences and deposits compared to one single enriched element anomaly. And the anomaly models exert a critical effect on the optimization of prospecting targets and their potential evaluation.展开更多
The Qulong deposit in Tibet is one of the largest porphyry copper-molybdenum deposits in China. We used short-wave infrared(SWIR) spectroscopy to examine the spectral characteristics of the extensively developed chlor...The Qulong deposit in Tibet is one of the largest porphyry copper-molybdenum deposits in China. We used short-wave infrared(SWIR) spectroscopy to examine the spectral characteristics of the extensively developed chlorite in this deposit. X-ray diffraction and electron microprobe analyses were used for phase identification and to obtain the chemical composition, ion substitution relationships, and formation environment of the chlorite. SWIR spectral parameters were applied to detect the hydrothermal centers. The results indicate that the wavelength of the absorption feature for Qulong chlorite Fe-OH(Pos2250) range from 2240 to 2268.4 nm;the chlorite substitution relationships are dominated by Mg-Fe substitution at the octahedral sites together with Al;-Si substitution at the tetrahedral sites;the chlorite formation temperatures range within the medium-low temperature hydrothermal alteration range from 164 to 281°C, with an average value of 264℃;the wavelength of the chlorite peak position for Fe-OH(2250 nm) absorption and its chemical composition are positively correlated with Al^(Ⅵ), Fe + Al^(Ⅵ), Fe/(Fe + Mg), Fe, and Fe + Al^(Ⅳ)but negatively correlated with Mg and Mg/(Fe + Mg);and the wavelength associated with the chlorite Fe-OH(2250 nm) absorption feature is positively correlated with the temperature at which the chlorite formed. These correlations indicate that more Fe and Al^(Ⅵ) ions and fewer Mg ions at the octahedral sites of chlorite lead to a longer the wavelength of the chlorite Fe-OH(2250 nm) absorption feature and a higher chlorite formation temperature. The wavelength of the Qulong chlorite Fe-OH(2250 nm) absorption feature(>2252 nm) can thus serve as an exploration indicator to guide the detection of hydrothermal centers in porphyry copper deposits. The results of the study indicate that the mineralogical and SWIR spectral characteristics of chlorite are significant indicators for locating hydrothermal centers within porphyry deposits.展开更多
The Wangjiazhuang porphyry copper(-molybdenum)deposit is located at Zouping volcanic basin in Shandong Province,East China and hosted in the Wangjiazhuang intrusive complex emplaced along a late volcanic conduit.There...The Wangjiazhuang porphyry copper(-molybdenum)deposit is located at Zouping volcanic basin in Shandong Province,East China and hosted in the Wangjiazhuang intrusive complex emplaced along a late volcanic conduit.There are two types of ores in this deposit:early disseminated and stockwork ores in the ore-bearing intrusion,and late massive sulfide-quartz veins above brecciated quartz monzonite.The ore minerals are mainly pyrite,chalcopyrite,and subordinately magnetite,tennantite,molybdenite with minor bornite,enargite,galena and sphalerite,etc.,and gangue minerals including K-feldspar,biotite,quartz,muscovite-sericite,chlorite and calcite.Combined with fluid inclusion study,the scanning electron microscope-cathodoluminescence(SEM-CL)study of quartz in the deposit and wall rocks shows significant differences between the two types of quartz in the ores.In addition,four types of primary-pseudosecondary fluid inclusions in the quartz have been recognized.They are one-or two-phase aqueous inclusions with vapor/liquid ratios less than 30%to 40%(type Ⅰ);gas-rich inclusions with vapor/liquid ratios more than 50%(type Ⅱ),some of which contain some small opaque minerals,probably chalcopyrite;multiphase fluid inclusions with daughter minerals of halite±anhydrite±opaque(chalcopyrite)±sylvite±hematite±unknown crystal(type Ⅲ);and mica-bearing fluid inclusions(type Ⅳ).Quartz containing abundant muscovite-bearing and halite-bearing fluid inclusions in the mineralized quartz monzonite with potassic-silicic alteration,have better oscillatory growth zoning with CL-colors from bright in the core to darker in the rim,indicating variations of element concentrations in the fluid media from which quartz grew during the later period of magmatic-hydrothermal process.In contrast,the quartz in the sulfide-quartz veins contains mainly fluid inclusions of low-to-medium salinities and does not show oscillatory zoning,indicating that there was less fluctuation in composition and element concentrations of the hydrothermal fluids.However,the quartz containing halite-bearing fluid inclusions and being associated with copper-molybdenum mineralization in the sulfide-quartz veins shows zoning in its rims,indicating variations in composition and element concentrations of the hydrothermal fluids.展开更多
基金financially supported by the Natural Science Foundation of China(Grant Nos.42272104,42172094 and 41772076)。
文摘The Wangjiazhuang Cu(-Mo)deposit,located within the Zouping volcanic basin in western Shandong Province,China,is unique in this area for having an economic value.In order to expound the metallogenetic characteristics of this porphyry-like hydrothermal deposit,a detailed fluid inclusion study has been conducted,employing the techniques of representative sampling,fluid inclusion petrography,microthermometry,Raman spectroscopy,LA-ICP-MS analysis of single fluid inclusions,as well as cathode fluorescence spectrometer analysis of host mineral quartz.The deposit contains mainly two types of orebodies,i.e.veinlet-dissemination-stockwork orebodies in the K-Si alteration zone and pegmatiticquartz sulfide veins above them.In addition,minor breccia ore occurs locally.Four types of fluid inclusions in the deposit and altered quartz monzonite are identified:L-type one-or two-phase aqueous inclusions,V-type vapor-rich inclusions with V/L ratios greater than 50%-90%,D-type multiphase fluid inclusions containing daughter minerals or solids and S-type silicate-bearing fluid inclusions containing mainly muscovite and biotite.Ore petrography and fluid inclusion study has revealed a three-stage mineralization process,driven by magmatic-hydrothermal fluid activity,as follows.Initially,a hydrothermal fluid,separated from the parent magma,infiltrated into the quartz monzonite,resulting in its extensive K-Si alteration,as indicated by silicate-bearing fluid inclusions trapped in altered quartz monzonite.This is followed by the early mineralization,the formation of quartz veinlets and dissemination-stockwork ores.During the main mineralization stage,due to the participation and mixing of meteoric groundwater with magmatic-sourced hydrothermal fluid,the cooling and phase separation caused deposition of metals from the hydrothermal fluids.As a result,the pegmatitic-quartz sulfide-vein ores formed.In the late mineralization stage,decreasing fluid salinity led to the formation of L-type aqueous inclusions and chalcopyrite-sulfosalt ore.Coexistence of V-type and D-type inclusions and their similar homogenization temperatures with different homogenization modes suggest that phase separation or boiling of the ore-forming fluids took place during the early and the main mineralization stages.The formation P-T conditions of S-type inclusions and the early and the main mineralization stages were estimated as ca.156-182 MPa and 450-650℃,350-450℃,18-35 MPa and 280-380℃,8-15 MPa,respectively,based on the microthermometric data of the fluid inclusions formed at the individual stages.
基金financially supported by the research special fund of public service sector from the Ministry of Land and Resources (No. 201111008)
文摘This paper discusses the enrichment and depletion regularities for porphyry coppermolybdenum ore deposits in different regions and varied deposit genetic types in the same area, taking three porphyry copper-molybdenum ore deposits （i.e., the Chengmenshan in Jiangxi, Wunugetushan in Inner Mongolia, Baishantang in Gansu） and two copper deposits in Gansu Province （the Huitongshan skarn deposit and Gongpoquan composite deposit） as case studies. The results show that porphyry Cu-Mo deposits or skarn copper deposits include both enrichment of the ore-forming elements and associated elements, and depletion of some lithophile dispersed elements, rare earth elements （REE） and some major elements. And the depleted elements vary with deposits, having generality and their own features. On a deposit scale, the positive anomalies of enriched elements and negative anomalies of depleted elements follow in a sequence to comprise regular anomaly models of spatial structures. The exploration in the Tongchang deposit in Jiangxi and Huitongshan deposit in Gansu suggests that anomaly models play a key role in the identification of mineral occurrences and deposits compared to one single enriched element anomaly. And the anomaly models exert a critical effect on the optimization of prospecting targets and their potential evaluation.
基金funded by Science and Technology Project of Tibet Autonomous Region(Grant Nos.XZ201801-GB-01XZ202102YD0024C)+2 种基金The Second Round of Comprehensive Investigation and Research on the Qinghai-Tibet Plateau(Grant No.2019QZKK0806)National Natural Science Foundation of China(Grant No.42002097)Demonstration Research on Alteration Mapping using Short-wave Infrared and Thermal Infrared Hyperspectral Technologies(Grant No.KK2102)。
文摘The Qulong deposit in Tibet is one of the largest porphyry copper-molybdenum deposits in China. We used short-wave infrared(SWIR) spectroscopy to examine the spectral characteristics of the extensively developed chlorite in this deposit. X-ray diffraction and electron microprobe analyses were used for phase identification and to obtain the chemical composition, ion substitution relationships, and formation environment of the chlorite. SWIR spectral parameters were applied to detect the hydrothermal centers. The results indicate that the wavelength of the absorption feature for Qulong chlorite Fe-OH(Pos2250) range from 2240 to 2268.4 nm;the chlorite substitution relationships are dominated by Mg-Fe substitution at the octahedral sites together with Al;-Si substitution at the tetrahedral sites;the chlorite formation temperatures range within the medium-low temperature hydrothermal alteration range from 164 to 281°C, with an average value of 264℃;the wavelength of the chlorite peak position for Fe-OH(2250 nm) absorption and its chemical composition are positively correlated with Al^(Ⅵ), Fe + Al^(Ⅵ), Fe/(Fe + Mg), Fe, and Fe + Al^(Ⅳ)but negatively correlated with Mg and Mg/(Fe + Mg);and the wavelength associated with the chlorite Fe-OH(2250 nm) absorption feature is positively correlated with the temperature at which the chlorite formed. These correlations indicate that more Fe and Al^(Ⅵ) ions and fewer Mg ions at the octahedral sites of chlorite lead to a longer the wavelength of the chlorite Fe-OH(2250 nm) absorption feature and a higher chlorite formation temperature. The wavelength of the Qulong chlorite Fe-OH(2250 nm) absorption feature(>2252 nm) can thus serve as an exploration indicator to guide the detection of hydrothermal centers in porphyry copper deposits. The results of the study indicate that the mineralogical and SWIR spectral characteristics of chlorite are significant indicators for locating hydrothermal centers within porphyry deposits.
基金We thank Prof.Chen Li from Peking University for assistance with the scanning electron microscope analysisThis study was financially supported by the Key R&D Program of China(No.2016YFC0600606)+2 种基金the Key R&D Program of Shandong Province(Nos.2017CXGC1601,2017CXGC1602,2017CXGC1603)the National Natural Science Foundation of China(Nos.41140025,41672084,41372086,41503038)the Special Fund for"Taishan Scholars"Project in Shandong Province.
文摘The Wangjiazhuang porphyry copper(-molybdenum)deposit is located at Zouping volcanic basin in Shandong Province,East China and hosted in the Wangjiazhuang intrusive complex emplaced along a late volcanic conduit.There are two types of ores in this deposit:early disseminated and stockwork ores in the ore-bearing intrusion,and late massive sulfide-quartz veins above brecciated quartz monzonite.The ore minerals are mainly pyrite,chalcopyrite,and subordinately magnetite,tennantite,molybdenite with minor bornite,enargite,galena and sphalerite,etc.,and gangue minerals including K-feldspar,biotite,quartz,muscovite-sericite,chlorite and calcite.Combined with fluid inclusion study,the scanning electron microscope-cathodoluminescence(SEM-CL)study of quartz in the deposit and wall rocks shows significant differences between the two types of quartz in the ores.In addition,four types of primary-pseudosecondary fluid inclusions in the quartz have been recognized.They are one-or two-phase aqueous inclusions with vapor/liquid ratios less than 30%to 40%(type Ⅰ);gas-rich inclusions with vapor/liquid ratios more than 50%(type Ⅱ),some of which contain some small opaque minerals,probably chalcopyrite;multiphase fluid inclusions with daughter minerals of halite±anhydrite±opaque(chalcopyrite)±sylvite±hematite±unknown crystal(type Ⅲ);and mica-bearing fluid inclusions(type Ⅳ).Quartz containing abundant muscovite-bearing and halite-bearing fluid inclusions in the mineralized quartz monzonite with potassic-silicic alteration,have better oscillatory growth zoning with CL-colors from bright in the core to darker in the rim,indicating variations of element concentrations in the fluid media from which quartz grew during the later period of magmatic-hydrothermal process.In contrast,the quartz in the sulfide-quartz veins contains mainly fluid inclusions of low-to-medium salinities and does not show oscillatory zoning,indicating that there was less fluctuation in composition and element concentrations of the hydrothermal fluids.However,the quartz containing halite-bearing fluid inclusions and being associated with copper-molybdenum mineralization in the sulfide-quartz veins shows zoning in its rims,indicating variations in composition and element concentrations of the hydrothermal fluids.
