Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep mineralization.This approach provides key information for the quantitative prediction of deep mineral localization,three-di...Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep mineralization.This approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking markers.The Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China Block.Abundant borehole data on oreforming elements underpin deep geochemical predictions.The methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)Correlation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was constructed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,contrasted by the northeastern and southeastern areas favorable for mineral exploration.展开更多
Objective The Geza arc in Yunnan Province,located in the southern Yidun arc,is an important part of the Sanjiang tectonic-magmatic belts in southwestern China and is a newly discovered copper polymetallic ore-concentr...Objective The Geza arc in Yunnan Province,located in the southern Yidun arc,is an important part of the Sanjiang tectonic-magmatic belts in southwestern China and is a newly discovered copper polymetallic ore-concentrating district.Recent studies show that the newly discovered Yanshanian porphyry Cu-Mo polymetallic mineralization superimposed in the Indosinian porphyry copper belt in this area.展开更多
The age of mineralization in a mining area is a primary factor in various researches related to ore\|forming process. It is that the uncertainty of mineralization ages of gold ore deposits in northern zone of eastern ...The age of mineralization in a mining area is a primary factor in various researches related to ore\|forming process. It is that the uncertainty of mineralization ages of gold ore deposits in northern zone of eastern Kunlun Mountains, Qinghai Province, restrains to probe the relationship of the deposits to the regional tectonic evolution. This paper documents the fission track method used to determine the ages of gold ore deposits in eastern Kunlun Mountains and considers the implication for the origin of the deposits.Eastern Kunlun Mountains is the northern part of the Qinghai—Tibet Plateau and is of three deep\|seated fault belts in about EW extension. This work mainly includes three gold ore districts. All of them, in the north of Mid\|Kunlun fault belt, belong to northern part of eastern Kunlun Mountains. The Yanjingou district, with geographical coordinate 96°00’E and 36°10’N, is located 60 km north of Hongqigou district . Both of them are large, typical tectonoalteration gold deposits and were formed in similar geological setting. Hongshuihe ore district is located 50 km east of Yanjingou district and includes tectonoalteration and magmatic cryptoexplosive gold deposits. Outcroped strata are dominantly Jinshuikou Group metamorphic rocks of Lower Proterozoic erathem. The occurrence area of igneous rocks, especially granitoid, accounts for about 90% in first two districts and become less in Hongshuihe district. The gold deposits occur in NW\|striking fault belts. The Rb\|Sr isochron age and K\|Ar isotopic age of Moyite relevant to the gold mineralization are respectively 228 25Ma and 207 1Ma. Rb\|Sr dating of diorite porphyrite is 209 09Ma. Sericite selected from Yanjingou orebody has 252 9Ma K\|Ar age. The ore in Hongqigou district has 197Ma K\|Ar age and 210Ma model age of Pb isotope of galena.展开更多
The Xiangcheng-Luoji area is located in the conjunction of the southern part of the ＂Sanjiang＂ mineralization belt and the west margin of Yangtze craton. The geological studies were carried out to know the Indosinia...The Xiangcheng-Luoji area is located in the conjunction of the southern part of the ＂Sanjiang＂ mineralization belt and the west margin of Yangtze craton. The geological studies were carried out to know the Indosinian large porphyry Cu polymetallic deposits. Recent studies revealed that the area existed in the superposition of Late Yanshanian acidic intrusive rock belt and developed Mo-Cu polymetallic mineralization where promising exploration results have been achieved. Through the systematic study of geochronology, formation age of the Renlin Mo-minieralization monzogranite is 81.7±1.1 Ma. Re-Os dating results concentrate on 82.34±1.2–88.27±1.23 Ma for the model ages of molbdenite of Tongchanggou Mo deposits, average age is 85 ± 2 Ma where seven data points constitute a good isochron which shows that they were the same period products of mineralization. Geochemical features shown that the rocks have a high content of SiO 2（66.59–77.36wt%）, alkaline-rich（K2O=2.68–6.08wt%; Na2O=0.50–4.91wt%; K2O/Na2 O ratios are 0.71–5.56, where average ratio of 1.89） and have aluminum–rich features（Al2O3 10.38–15.15wt%） with σ values less than 3.3. Which indicate that they belong to the high-K calc-alkali to shoshonite series. Geochemistry of Yanshanian intrusions shows that rocks are enrich in LREE with obvious negative δEu anomalies, enrichment of trace elements like, LILE elements（Rb, Th, Ba） with a relative loss of Ba, and loss of high field strength elements（Nb, Ta, P, Ti） and HREE elements. The granite genetic classification diagram shows that the granites belong to A-type granite and formatted in syn-collision tectonic environment. Meanwhile, the Yanshanian granites also inherited the characteristics of island arc environment which formed in the process of crustal melting caused by upwelling of asthenospheric substances in the extensional tectonic background. The process of partial melting existed substances from the deep（lower crust or upper mantle） which have been added. In the Xiangcheng-Luoji area, monzogranite and granodiorite porphyry bodies are widely developed Mo polymetallic mineralization, the deep porphyry mineralization have great potential for geological prospecting.展开更多
Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the d...Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK.展开更多
The Jiapigou gold deposits are typical vein type deposits associated withArchaean greenstone belts in China. According to the crosscutting relationships between dykesand auriferous veins, single hydrothermal zircon U-...The Jiapigou gold deposits are typical vein type deposits associated withArchaean greenstone belts in China. According to the crosscutting relationships between dykesand auriferous veins, single hydrothermal zircon U-Pb dating and quartz K-Ar,^(40)Ar-^(39)Ar andRb-Sr datings, the main mineralization stage of the Jiapigou deposit has been determined to be2469-2475 Ma, while mineralization superimposition on the gold deposit occurred in1800-2000 Ma and 130-272 Ma. They form a mineralization framework of one oldermetallogenic epoch (Late Archaean-Early Proterozoic) and one younger metallogenic epoch(Mesozoic) of gold deposits in Archaean greenstone belts in China.展开更多
The Xiaoban gold deposit is a large-size deposit recently found in middlearea of Fujian Province. It belongs to magmatic hydrothermal type occurred in Mayuan Groupmetamorphic rocks of Middle Proterozoic and is control...The Xiaoban gold deposit is a large-size deposit recently found in middlearea of Fujian Province. It belongs to magmatic hydrothermal type occurred in Mayuan Groupmetamorphic rocks of Middle Proterozoic and is controlled by low angle fault (detachment)structures. The contents of Au in Mayuan Group metamorphic rocks, Caledonian-Indosinian deformedgranite and early Yanshanian granite are higher with Au enrichment coefficient of 2. 06-5.68, 5.11and 6.67 than those in other geological bodies. And the higher enrichment coefficients (>2) of Ag,S, Sn and Te are similar to those of gold ore. Meanwhile, the distribution of Au in Mayuan Groupmetamorphic rocks and early Yanshanian granite with a low D-value (0.58 and 0.67) is favorable togold mineralization. REE characteristics of gold ore, ratios of (LREE/HREE), (La/Sm)_n, (Yb/Lu)_n,(La/Tb)_n and (Sm/Nd)_n are similar to Mayuan Group metamorphic rocks, only non or little normal Euabnormal of ore is dissimilar to metamorphic rocks. The δ(^(34)S) of the gold ore, with a highhomogenization, is (-4.7X10^(-3) - (-2.7X 10^(-3)). The study of inclusion indicates 180-249℃ ofmineralization temperature, 3. 69 %-11. 81 % of salinities and 0. 869-0.991 g/cm^3 of densities ofmineralization fluid. Based on hydrogen and oxygen isotope (δ(^(18)O) = 11. 0 X 10^(-3) -11.7 X10^(-3), δ(D) = (-48 X 10^(-3)) - (-62 X 10^(-3))) and initial w(^(87)Sr)/w(^(86)Sr) =0. 715,combining to the analysis of geological history, regional metamorphism and magamtic activity, theauthors confirm that the source for the ore fluid was mainly from magmatic, partly from metamorphicwater, and with a little influence of meteoric water. Isotopic dating made on Rb-Sr isochron age of182 Ma, by using alteration minerals of gold-ores from the deposit, indicates that themineralization occurs in early Yanshanian epoch. This is close to the age of 187 Ma of the Anchunmagmatite with a similar alteration and gold mineralization to the Xiaoban gold deposit. The age ofearly Yanshanian epoch of the Xiaoban gold is indentical with the characteristics of southern Chinagold metal-logenic belt and the geotectonic evolution of the transition from paleo-Asian system andpaleo-Tethyan system to paleo-Pacific active continental margin in eastern Asia.展开更多
Based on palaeomagnetic studies of the Precambrian gold deposits in the Xiong'ershan area, Henan Province, the authors infer that the ore-forming processes of the Beiling alteration-type gold ore deposit and the D...Based on palaeomagnetic studies of the Precambrian gold deposits in the Xiong'ershan area, Henan Province, the authors infer that the ore-forming processes of the Beiling alteration-type gold ore deposit and the Dianfang breccia-type gold ore deposit started in the Proterozoic, and was superimposed by later mineralization, whereas the mineralization age of the Jiguanshan quartz- vein type gold ore deposit is Yanshanian.展开更多
A non-contacting electrical resistivity measurement device was used to investigate the effect of different types and contents of mineral admixtures on the hydration perfrormanee of mortars during early age. The experi...A non-contacting electrical resistivity measurement device was used to investigate the effect of different types and contents of mineral admixtures on the hydration perfrormanee of mortars during early age. The experimental results show that the changes of measured resistivity with time of hydration can be used to describe the hydration characteristics of cement-based materials, as well as the physical and chemical behavior of fly ash; blast furnace slag and silica fume at the very early ages. With an increasing replacement ratio of mineral admixtures, for the specimens blended with fly ash or slag, the resistivity increases firstly, then the following flatting period extends and after setting the resistivity increasing becomes slow and consequently a lower resistivity value at 24 hours occurs. This is due to the dilution effect and lower pozzolanicl hydraulic activity of fly ash and slag. However, for the samples incorporated with silica fume, the resistivity value through 24 hours is lower with shorter flatting period and larger slope in the resistivity curves, which is because of its particle size effect and higher pozzolanic activity of silica fume. Moreover, non-contacting resistivity measurement might provide a helpful information to predict the long term performanee including the durability of cement-based materials at early ages.展开更多
The Neoproterozoic Riviera W-REE-Mo deposit is one of the largest unmined tungsten resources in the world and is associated with pervasively altered A-type granites of the Neoproterozoic Cape Granite Suite Western Cap...The Neoproterozoic Riviera W-REE-Mo deposit is one of the largest unmined tungsten resources in the world and is associated with pervasively altered A-type granites of the Neoproterozoic Cape Granite Suite Western Cape, South Africa. The present study investigated the mineral chemistry of scheelite, the principal ore mineral with the aim to record the variation of solid solution molybdenum for geometallurgical purposes and also as an indicator of changing redox conditions of the mineralizing hydrothermal fluids. Methodology included UV-fluorescence studies and micro-analyses by LA-ICP-MS. Results have shown that at least four phases of scheelite are hosted by the endoskarn zone, potassic alteration zone and various quartz-carbonate veins. This reflects hydrothermal fluid evolution from early stage reduced to late stage, vein associated and more oxidized. The molybdenum content of the dominant early phase scheelite is low and renders the deposit amenable to low penalty mineral recovery.展开更多
Objective The Youjiang basin,also named"Dian-Qian-Gui Golden Triangle",contains a cluster of Carlin-like gold deposits(Deng and Wang,2016).Due to the uncertainty of mineralization age and the absence of coet...Objective The Youjiang basin,also named"Dian-Qian-Gui Golden Triangle",contains a cluster of Carlin-like gold deposits(Deng and Wang,2016).Due to the uncertainty of mineralization age and the absence of coetaneous magmatic rocks(Chen et al.,2015),the relationship between magmatism and Au mineralization still remains controversial in recent years(Hou et al.,2016).The Late展开更多
Ag3PO4/Ag/Ag2Mo2O7 composite photocatalyst was successfully prepared via an in situ precipitation method. The as-prepared Ag3PO4/Ag/Ag2Mo2O7 nanocomposite included Ag3PO4 nanoparticles （NPs） as well as Ag NPs assemb...Ag3PO4/Ag/Ag2Mo2O7 composite photocatalyst was successfully prepared via an in situ precipitation method. The as-prepared Ag3PO4/Ag/Ag2Mo2O7 nanocomposite included Ag3PO4 nanoparticles （NPs） as well as Ag NPs assembling on the surface of Ag2Mo2O7 nanowires. Under visible light irradiation （λ〉420 nm）, the Ag3PO4/Ag/Ag2Mo2O7 com- posite degraded rhodamine B （Rh B） efficiently and showed much higher photocatalytic efficiency than pure AgaPO4, Ag2Mo2O7, or Ag3PO4/Ag2Mo2O7. It was elucidated that the excellent photocatalytic performance of Ag3PO4/Ag/Ag2Mo2O7 for the degradation of Rh B under visible light could be ascribed to the high specific surface area, the extended absorption in the visible light region resulting from the Ag3PO4/Ag loading, and the effi- cient separation of photogenerated electrons and holes through the ternary heterostrucure composed of Ag3PO4, Ag and Ag2Mo2O7.展开更多
基金supported by the Key Research Project of China Geological Survey(Grant No.DD20230564)the Research Project of Natural Resources Department of Gansu Province(Grant No.202219)。
文摘Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep mineralization.This approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking markers.The Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China Block.Abundant borehole data on oreforming elements underpin deep geochemical predictions.The methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)Correlation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was constructed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,contrasted by the northeastern and southeastern areas favorable for mineral exploration.
基金financially supported by the National Natural Science Foundation of China (grant No.41502076)the Leading Talents Plan Project of Science and Technology of Yunnan Province (grant No.2013HA001)the Science Research Fund of Yunnan Provincial Education Department (grant No.2015Y066)
文摘Objective The Geza arc in Yunnan Province,located in the southern Yidun arc,is an important part of the Sanjiang tectonic-magmatic belts in southwestern China and is a newly discovered copper polymetallic ore-concentrating district.Recent studies show that the newly discovered Yanshanian porphyry Cu-Mo polymetallic mineralization superimposed in the Indosinian porphyry copper belt in this area.
文摘The age of mineralization in a mining area is a primary factor in various researches related to ore\|forming process. It is that the uncertainty of mineralization ages of gold ore deposits in northern zone of eastern Kunlun Mountains, Qinghai Province, restrains to probe the relationship of the deposits to the regional tectonic evolution. This paper documents the fission track method used to determine the ages of gold ore deposits in eastern Kunlun Mountains and considers the implication for the origin of the deposits.Eastern Kunlun Mountains is the northern part of the Qinghai—Tibet Plateau and is of three deep\|seated fault belts in about EW extension. This work mainly includes three gold ore districts. All of them, in the north of Mid\|Kunlun fault belt, belong to northern part of eastern Kunlun Mountains. The Yanjingou district, with geographical coordinate 96°00’E and 36°10’N, is located 60 km north of Hongqigou district . Both of them are large, typical tectonoalteration gold deposits and were formed in similar geological setting. Hongshuihe ore district is located 50 km east of Yanjingou district and includes tectonoalteration and magmatic cryptoexplosive gold deposits. Outcroped strata are dominantly Jinshuikou Group metamorphic rocks of Lower Proterozoic erathem. The occurrence area of igneous rocks, especially granitoid, accounts for about 90% in first two districts and become less in Hongshuihe district. The gold deposits occur in NW\|striking fault belts. The Rb\|Sr isochron age and K\|Ar isotopic age of Moyite relevant to the gold mineralization are respectively 228 25Ma and 207 1Ma. Rb\|Sr dating of diorite porphyrite is 209 09Ma. Sericite selected from Yanjingou orebody has 252 9Ma K\|Ar age. The ore in Hongqigou district has 197Ma K\|Ar age and 210Ma model age of Pb isotope of galena.
基金supported by the National Basic Research Program of China (973 Program) (Grant No. 2009CB421007)the Science and Technology Leading Talents Training Plan Program of Yunnan Province (Grant No.2013HA001)
文摘The Xiangcheng-Luoji area is located in the conjunction of the southern part of the ＂Sanjiang＂ mineralization belt and the west margin of Yangtze craton. The geological studies were carried out to know the Indosinian large porphyry Cu polymetallic deposits. Recent studies revealed that the area existed in the superposition of Late Yanshanian acidic intrusive rock belt and developed Mo-Cu polymetallic mineralization where promising exploration results have been achieved. Through the systematic study of geochronology, formation age of the Renlin Mo-minieralization monzogranite is 81.7±1.1 Ma. Re-Os dating results concentrate on 82.34±1.2–88.27±1.23 Ma for the model ages of molbdenite of Tongchanggou Mo deposits, average age is 85 ± 2 Ma where seven data points constitute a good isochron which shows that they were the same period products of mineralization. Geochemical features shown that the rocks have a high content of SiO 2（66.59–77.36wt%）, alkaline-rich（K2O=2.68–6.08wt%; Na2O=0.50–4.91wt%; K2O/Na2 O ratios are 0.71–5.56, where average ratio of 1.89） and have aluminum–rich features（Al2O3 10.38–15.15wt%） with σ values less than 3.3. Which indicate that they belong to the high-K calc-alkali to shoshonite series. Geochemistry of Yanshanian intrusions shows that rocks are enrich in LREE with obvious negative δEu anomalies, enrichment of trace elements like, LILE elements（Rb, Th, Ba） with a relative loss of Ba, and loss of high field strength elements（Nb, Ta, P, Ti） and HREE elements. The granite genetic classification diagram shows that the granites belong to A-type granite and formatted in syn-collision tectonic environment. Meanwhile, the Yanshanian granites also inherited the characteristics of island arc environment which formed in the process of crustal melting caused by upwelling of asthenospheric substances in the extensional tectonic background. The process of partial melting existed substances from the deep（lower crust or upper mantle） which have been added. In the Xiangcheng-Luoji area, monzogranite and granodiorite porphyry bodies are widely developed Mo polymetallic mineralization, the deep porphyry mineralization have great potential for geological prospecting.
基金jointly supported by National Key R&D Program of China(Grant No.2017YFC0504002)Natural Science Foundation of China(No.31270679)
文摘Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK.
基金This study is a contribution to Project 90051-01,a state key gold scientific and technological project during the 8th Five-Year Plan period,and Project 92-94-40 carried out by the State Gold Administration.
文摘The Jiapigou gold deposits are typical vein type deposits associated withArchaean greenstone belts in China. According to the crosscutting relationships between dykesand auriferous veins, single hydrothermal zircon U-Pb dating and quartz K-Ar,^(40)Ar-^(39)Ar andRb-Sr datings, the main mineralization stage of the Jiapigou deposit has been determined to be2469-2475 Ma, while mineralization superimposition on the gold deposit occurred in1800-2000 Ma and 130-272 Ma. They form a mineralization framework of one oldermetallogenic epoch (Late Archaean-Early Proterozoic) and one younger metallogenic epoch(Mesozoic) of gold deposits in Archaean greenstone belts in China.
文摘The Xiaoban gold deposit is a large-size deposit recently found in middlearea of Fujian Province. It belongs to magmatic hydrothermal type occurred in Mayuan Groupmetamorphic rocks of Middle Proterozoic and is controlled by low angle fault (detachment)structures. The contents of Au in Mayuan Group metamorphic rocks, Caledonian-Indosinian deformedgranite and early Yanshanian granite are higher with Au enrichment coefficient of 2. 06-5.68, 5.11and 6.67 than those in other geological bodies. And the higher enrichment coefficients (>2) of Ag,S, Sn and Te are similar to those of gold ore. Meanwhile, the distribution of Au in Mayuan Groupmetamorphic rocks and early Yanshanian granite with a low D-value (0.58 and 0.67) is favorable togold mineralization. REE characteristics of gold ore, ratios of (LREE/HREE), (La/Sm)_n, (Yb/Lu)_n,(La/Tb)_n and (Sm/Nd)_n are similar to Mayuan Group metamorphic rocks, only non or little normal Euabnormal of ore is dissimilar to metamorphic rocks. The δ(^(34)S) of the gold ore, with a highhomogenization, is (-4.7X10^(-3) - (-2.7X 10^(-3)). The study of inclusion indicates 180-249℃ ofmineralization temperature, 3. 69 %-11. 81 % of salinities and 0. 869-0.991 g/cm^3 of densities ofmineralization fluid. Based on hydrogen and oxygen isotope (δ(^(18)O) = 11. 0 X 10^(-3) -11.7 X10^(-3), δ(D) = (-48 X 10^(-3)) - (-62 X 10^(-3))) and initial w(^(87)Sr)/w(^(86)Sr) =0. 715,combining to the analysis of geological history, regional metamorphism and magamtic activity, theauthors confirm that the source for the ore fluid was mainly from magmatic, partly from metamorphicwater, and with a little influence of meteoric water. Isotopic dating made on Rb-Sr isochron age of182 Ma, by using alteration minerals of gold-ores from the deposit, indicates that themineralization occurs in early Yanshanian epoch. This is close to the age of 187 Ma of the Anchunmagmatite with a similar alteration and gold mineralization to the Xiaoban gold deposit. The age ofearly Yanshanian epoch of the Xiaoban gold is indentical with the characteristics of southern Chinagold metal-logenic belt and the geotectonic evolution of the transition from paleo-Asian system andpaleo-Tethyan system to paleo-Pacific active continental margin in eastern Asia.
基金the Youth Fund of the Chinese Academy of Geological Science (No.9011)
文摘Based on palaeomagnetic studies of the Precambrian gold deposits in the Xiong'ershan area, Henan Province, the authors infer that the ore-forming processes of the Beiling alteration-type gold ore deposit and the Dianfang breccia-type gold ore deposit started in the Proterozoic, and was superimposed by later mineralization, whereas the mineralization age of the Jiguanshan quartz- vein type gold ore deposit is Yanshanian.
基金Funded by the National Natural Science Foundation of China(No.50539010)
文摘A non-contacting electrical resistivity measurement device was used to investigate the effect of different types and contents of mineral admixtures on the hydration perfrormanee of mortars during early age. The experimental results show that the changes of measured resistivity with time of hydration can be used to describe the hydration characteristics of cement-based materials, as well as the physical and chemical behavior of fly ash; blast furnace slag and silica fume at the very early ages. With an increasing replacement ratio of mineral admixtures, for the specimens blended with fly ash or slag, the resistivity increases firstly, then the following flatting period extends and after setting the resistivity increasing becomes slow and consequently a lower resistivity value at 24 hours occurs. This is due to the dilution effect and lower pozzolanicl hydraulic activity of fly ash and slag. However, for the samples incorporated with silica fume, the resistivity value through 24 hours is lower with shorter flatting period and larger slope in the resistivity curves, which is because of its particle size effect and higher pozzolanic activity of silica fume. Moreover, non-contacting resistivity measurement might provide a helpful information to predict the long term performanee including the durability of cement-based materials at early ages.
文摘The Neoproterozoic Riviera W-REE-Mo deposit is one of the largest unmined tungsten resources in the world and is associated with pervasively altered A-type granites of the Neoproterozoic Cape Granite Suite Western Cape, South Africa. The present study investigated the mineral chemistry of scheelite, the principal ore mineral with the aim to record the variation of solid solution molybdenum for geometallurgical purposes and also as an indicator of changing redox conditions of the mineralizing hydrothermal fluids. Methodology included UV-fluorescence studies and micro-analyses by LA-ICP-MS. Results have shown that at least four phases of scheelite are hosted by the endoskarn zone, potassic alteration zone and various quartz-carbonate veins. This reflects hydrothermal fluid evolution from early stage reduced to late stage, vein associated and more oxidized. The molybdenum content of the dominant early phase scheelite is low and renders the deposit amenable to low penalty mineral recovery.
文摘Objective The Youjiang basin,also named"Dian-Qian-Gui Golden Triangle",contains a cluster of Carlin-like gold deposits(Deng and Wang,2016).Due to the uncertainty of mineralization age and the absence of coetaneous magmatic rocks(Chen et al.,2015),the relationship between magmatism and Au mineralization still remains controversial in recent years(Hou et al.,2016).The Late
基金supported by the National Natural Science Foundation of China(No.21407059,No.21576112,No.21407064,and No.21607051)the Science Development Project of Jiangsu Province(BK20140527)+1 种基金the Science and Technology Research Project of the Department of Education of Jilin Province(No.2015220)the Open Subject of the State Key Laboratory of Rare Earth Resource Utilization(RERU2017011)
文摘Ag3PO4/Ag/Ag2Mo2O7 composite photocatalyst was successfully prepared via an in situ precipitation method. The as-prepared Ag3PO4/Ag/Ag2Mo2O7 nanocomposite included Ag3PO4 nanoparticles （NPs） as well as Ag NPs assembling on the surface of Ag2Mo2O7 nanowires. Under visible light irradiation （λ〉420 nm）, the Ag3PO4/Ag/Ag2Mo2O7 com- posite degraded rhodamine B （Rh B） efficiently and showed much higher photocatalytic efficiency than pure AgaPO4, Ag2Mo2O7, or Ag3PO4/Ag2Mo2O7. It was elucidated that the excellent photocatalytic performance of Ag3PO4/Ag/Ag2Mo2O7 for the degradation of Rh B under visible light could be ascribed to the high specific surface area, the extended absorption in the visible light region resulting from the Ag3PO4/Ag loading, and the effi- cient separation of photogenerated electrons and holes through the ternary heterostrucure composed of Ag3PO4, Ag and Ag2Mo2O7.
