The Nage Cu-Pb polymetallic deposit is located in the transitional zone of the Yangtze craton and cathaysia,that is the southwest of Jiangnan orogenic belt. The mainly strata are Wentong formation of Mesoproterozoic S...The Nage Cu-Pb polymetallic deposit is located in the transitional zone of the Yangtze craton and cathaysia,that is the southwest of Jiangnan orogenic belt. The mainly strata are Wentong formation of Mesoproterozoic Sibo group and the Jialu formation(Qbj) ,Wuye formation(Qbw) ,Fanzhao formation(Qbf) and Gongdong formation(Qbg) of the Neoproterozoic Qingbaikou System Xiajiang group.展开更多
The Baoshan Cu-Pb-Zn polymetallic deposit is lied in the central Nanling mineralization zone,and belongs to the junction area of the Chenzhou-Linwu fault zone and the Leiyang-Linwu fault zone.It is a significant part ...The Baoshan Cu-Pb-Zn polymetallic deposit is lied in the central Nanling mineralization zone,and belongs to the junction area of the Chenzhou-Linwu fault zone and the Leiyang-Linwu fault zone.It is a significant part of Nanling polymetallic deposit belt.The outcropping stratas consist of upper Devonian Shetianqiao,Xikuangshan Formation,Lower Carboniferous Menggong’ao,Shidengzi,Ceshui,and Zimenqiao Formation.Igneous rocks in the Baoshan ore area mainly comprise granodiorite porphyry.Furthermore,the radio isotopic age ranges from 123 Ma to 183 Ma,belonging to the early to middle Yanshanian.展开更多
1 Introduction Southeast Yunnan is the convergent place of the Yangtze,Indochina blocks(Xu Wei,et al.2008).The Hongshiyan Pb-Zn-Cu polymetallic deposit is located in Wenshan Prefecture,Yunnan Province.It is a typical ...1 Introduction Southeast Yunnan is the convergent place of the Yangtze,Indochina blocks(Xu Wei,et al.2008).The Hongshiyan Pb-Zn-Cu polymetallic deposit is located in Wenshan Prefecture,Yunnan Province.It is a typical large sized VMS-type deposit discovered in recent years.The major ore minerals are sphalerite,galena,chalcopyrite ect.展开更多
An isochron age of 282±20 (95% conf. limit) Ma of the sulfide ores in the Huangshandong Cu-Ni sulfide deposit, the East Tianshan Mountains has been obtained through Re-Os isotopic measurement. The age implies tha...An isochron age of 282±20 (95% conf. limit) Ma of the sulfide ores in the Huangshandong Cu-Ni sulfide deposit, the East Tianshan Mountains has been obtained through Re-Os isotopic measurement. The age implies that the Cu-Ni sulfide deposit and other related deposits in the same area occurred in a Permian extensional environment of post-collision instead of Devonian-Early Carboniferous ophiolite-related oceanic or island arc environments inferred before. It shares the same ages with the orogenic and epithermal gold deposit systems in the same area. An initial 187Os/188Os ratio of 0.25±0.04 (1σ) and a γos value of 99 on average display the participation of large quantities of crustal components into the rock-forming and ore-forming system during mineralization and magmatic emplacement.展开更多
The Zhou＇an PGE-Cu-Ni deposit was recently discovered in the Qinling orogenic belt bound by the Yangtze and the North China Cratons. It is a blind deposit thoroughly covered by the Cenozoic alluvial sediments in the ...The Zhou＇an PGE-Cu-Ni deposit was recently discovered in the Qinling orogenic belt bound by the Yangtze and the North China Cratons. It is a blind deposit thoroughly covered by the Cenozoic alluvial sediments in the Nanyang Basin. As the first large PGE-Cu-Ni deposit discovered in the Qinling-Dabie-Sulu orogenic belt, its geological and geochemical characteristic, isotope age, genesis and tectonic setting are of wide concern in both scientific studies and ore exploration. In this contribution, we report the results obtained from a pioneering study. The Zhou＇an ultramafic complex is ferruginous, with m/f = 4.79-5.08, and shows the nature of tholeiite series. It is rich in light rare earth elements, Rb, Th, U, La, Sm, Zr and Hf, and poor in heavy rare earth elements, Nd and Ta, suggesting an intraplate setting. It has high S7Sr/S6Sr and low 143Nd/144Nd ratios. The ratios of Zr/Nb, La/Nb, Ba/ Nb, Rb/Nb, Th/Nb, Th/La and Ba/La, suggest the magma originated from lithosphere mantle. The Fo values of olivine and Pd/Ir-Ni/Cu diagram suggest primary magma was High Mg basalt. The laser ablation inductively coupled plasma atomic emission spectroscopy zircon U-Pb age is 641.5 ± 3.7 Ma.展开更多
The Kukaazi Pb-Zn-Cu-W polymetallic deposit, located in the Western Kunlun orogenic belt, is a newly discovered skarn-type deposit. Ore bodies mainly occur in the forms of lenses and veins along beddings of the Mesopr...The Kukaazi Pb-Zn-Cu-W polymetallic deposit, located in the Western Kunlun orogenic belt, is a newly discovered skarn-type deposit. Ore bodies mainly occur in the forms of lenses and veins along beddings of the Mesoproterozoic metamorphic rocks. Three ore blocks, KⅠ,KⅡ, and KⅢ, have been outlined in different parts of the Kukaazi deposit in terms of mineral assemblages. The KⅠ ore block is mainly composed of chalcopyrite, scheelite,pyrrhotite, sphalerite, galena and minor pyrite, arsenopyrite,and molybdenite, whereas the other two ore blocks are made up of galena, sphalerite, magnetite and minor arsenopyrite and pyrite. In this study, we obtained a molybdenite isochron Re–Os age of 450.5 ± 6.4 Ma(2σ,MSWD = 0.057) and a scheelite Sm–Nd isochron age of 426 ± 59 Ma(2σ, MSWD = 0.49) for the KⅠ ore block.They are broadly comparable to the ages of granitoid in the region. Scheelite grains from the KⅠ ore block contain high abundances of rare earth elements(REE, 42.0–95.7 ppm)and are enriched in light REE compared to heavy REE, with negative Eu anomalies(δEu = 0.13–0.55). They display similar REE patterns and Sm/Nd ratios to those of the coeval granitoids in the region. Moreover, they also have similar Sr and Nd isotopes [ ^(87)Sr/ ^(86)Sr = 0.7107–0.7118;ε_(Nd)(t) =-4.1 to-4.0] to those of such granitoids, implying that the tungsten-bearing fluids in the Kukaazi deposit probably originate from the granitic magmas. Our results first defined that the Early Paleozoic granitoids could lead to economic Mo–W–(Cu) mineralization at some favorable districts in the Western Kunlun orogenic belt and could be prospecting exploration targets.展开更多
Kupferschiefer type Cu-Ag deposits occur in the Upper Permian Xuanwei Formation in the Leshan-Muchuan region at the southwestern edge of the Sichuan Basin. Evidences from geology, major element, REE and thermolurnines...Kupferschiefer type Cu-Ag deposits occur in the Upper Permian Xuanwei Formation in the Leshan-Muchuan region at the southwestern edge of the Sichuan Basin. Evidences from geology, major element, REE and thermolurninescence analyses suggest that these Kupferschiefer type CuAg deposits were formed during diagenesis and the ore-forming fluids were derived frorn the underlying basalt. Fluid dynamic analyses show that the ore-forming fluids migrated in a unicellular convection, fluids migrated through the basalt, leaching Cu and Ag frorn basalt and forming orebearing solutions, up the western basement highs, moved laterally along the Xuanwei Formation toward the basin centers, presumably to sink back down into the basalt, completing a convection cycle which was about 15 km long, 300 m high and subhorizontal. Further analysis and calculation suggest that there are good geological, tectonic and fluid-dynamic conditions to form middle-scale Cu and giant Ag Kupferschiefer type deposits, but superlarge deposits are unlikely to be formed in this region.展开更多
The Bainiuchang deposit in Yunnan Province, China, is located geographically between the Gejiu ore field and the Dulong ore field. In addition to >7000 t Ag reserves, the deposit possesses large-scale Pb, Zn, Sn re...The Bainiuchang deposit in Yunnan Province, China, is located geographically between the Gejiu ore field and the Dulong ore field. In addition to >7000 t Ag reserves, the deposit possesses large-scale Pb, Zn, Sn reserves and a mass of dispersed elements (i.e., In, Cd, Ge, Ga, etc.). Based on systematic studies of sulfur isotopic composition, the authors conclude: The Bainiuchang deposit experienced two epochs of metallogenesis, i.e., the Middle-Cambrian sea-floor exhalative sedimentary metallogenic epoch and the Yanshanian magmatic hydrothermal superimposition metallogenic epoch. In the two metallogenic epochs, the δ34S values of sulfides were all near 0, showing a tendency of being enriched slightly in heavy sulfur. The δ34S values of sulfides in the early metallogenic epoch are within the range of 2‰–5‰ with a peak value range of 2‰–3‰ and an average of 3.0‰, and those of sulfides in the late metallogenic epoch are within the range of 2‰–6‰ with a peak value of 3‰–4‰ and an average of 3.9‰. For the single metallogenic epoch, sulfur in the ore-forming fluids in the early epoch already reached isotopic equilibrium and was derived mainly from underneath the magma chamber or basement metamorphic igneous rocks. Sulfur in the sulfides in the late epoch was derived mainly from magmatic hydrothermal fluids formed in the process of remelting of the basement metamorphic igneous rocks.展开更多
In terms of major element, trace element and REE geochemical characteristics of volcanic rocks in the area studied and by making use of the TiO\-2\|K\-2O\|P\-2O\-5, Th\|Hf\|Ta and Zr\|Nb\|Y trianglar diagrams and the ...In terms of major element, trace element and REE geochemical characteristics of volcanic rocks in the area studied and by making use of the TiO\-2\|K\-2O\|P\-2O\-5, Th\|Hf\|Ta and Zr\|Nb\|Y trianglar diagrams and the environmental discrimination diagrams of incompatible element distribution patterns, the authors have drawn some conclusions that are different from those by previous workers. It is concluded that volcanic rocks in the Laochang Ag polymetallic deposit at Lancang, Yunnan belong to continental within\|plate alkali basalts, and that their geotectonic setting seems to be at the northeastern margin of East Gondwana Land.展开更多
基金National Basic Research Program of China(No.2007CB411402)Cooperation Program of Institute of Geochemistry and Guizhou Geology and Minerals Bureau 102 Geology Group
文摘The Nage Cu-Pb polymetallic deposit is located in the transitional zone of the Yangtze craton and cathaysia,that is the southwest of Jiangnan orogenic belt. The mainly strata are Wentong formation of Mesoproterozoic Sibo group and the Jialu formation(Qbj) ,Wuye formation(Qbw) ,Fanzhao formation(Qbf) and Gongdong formation(Qbg) of the Neoproterozoic Qingbaikou System Xiajiang group.
基金Supported by the Program of Superseding Resources Prospecting in Crisis Mines in China(20089927)
文摘The Baoshan Cu-Pb-Zn polymetallic deposit is lied in the central Nanling mineralization zone,and belongs to the junction area of the Chenzhou-Linwu fault zone and the Leiyang-Linwu fault zone.It is a significant part of Nanling polymetallic deposit belt.The outcropping stratas consist of upper Devonian Shetianqiao,Xikuangshan Formation,Lower Carboniferous Menggong’ao,Shidengzi,Ceshui,and Zimenqiao Formation.Igneous rocks in the Baoshan ore area mainly comprise granodiorite porphyry.Furthermore,the radio isotopic age ranges from 123 Ma to 183 Ma,belonging to the early to middle Yanshanian.
基金supported by National Science Foundation of China (NSFC) project (40372049)innovation team of KMUST ore-forming dynamics and prediction of concealed deposits (2008)
文摘1 Introduction Southeast Yunnan is the convergent place of the Yangtze,Indochina blocks(Xu Wei,et al.2008).The Hongshiyan Pb-Zn-Cu polymetallic deposit is located in Wenshan Prefecture,Yunnan Province.It is a typical large sized VMS-type deposit discovered in recent years.The major ore minerals are sphalerite,galena,chalcopyrite ect.
基金the National Natural Science Foundation of China(No.40172021)the Major State Basic Research Program of the People’s Republic of China(No.G1999043211)the New Round Geological Survey Project (DKD9902001,2001BA609A-07-04).
文摘An isochron age of 282±20 (95% conf. limit) Ma of the sulfide ores in the Huangshandong Cu-Ni sulfide deposit, the East Tianshan Mountains has been obtained through Re-Os isotopic measurement. The age implies that the Cu-Ni sulfide deposit and other related deposits in the same area occurred in a Permian extensional environment of post-collision instead of Devonian-Early Carboniferous ophiolite-related oceanic or island arc environments inferred before. It shares the same ages with the orogenic and epithermal gold deposit systems in the same area. An initial 187Os/188Os ratio of 0.25±0.04 (1σ) and a γos value of 99 on average display the participation of large quantities of crustal components into the rock-forming and ore-forming system during mineralization and magmatic emplacement.
基金granted by the National Natural Science Fund of China (No. 41072058)the Scientific Research Special Subject for Public Welfare Profession (200911007 and201011058)China central college fund(CHD2011TD007)
文摘The Zhou＇an PGE-Cu-Ni deposit was recently discovered in the Qinling orogenic belt bound by the Yangtze and the North China Cratons. It is a blind deposit thoroughly covered by the Cenozoic alluvial sediments in the Nanyang Basin. As the first large PGE-Cu-Ni deposit discovered in the Qinling-Dabie-Sulu orogenic belt, its geological and geochemical characteristic, isotope age, genesis and tectonic setting are of wide concern in both scientific studies and ore exploration. In this contribution, we report the results obtained from a pioneering study. The Zhou＇an ultramafic complex is ferruginous, with m/f = 4.79-5.08, and shows the nature of tholeiite series. It is rich in light rare earth elements, Rb, Th, U, La, Sm, Zr and Hf, and poor in heavy rare earth elements, Nd and Ta, suggesting an intraplate setting. It has high S7Sr/S6Sr and low 143Nd/144Nd ratios. The ratios of Zr/Nb, La/Nb, Ba/ Nb, Rb/Nb, Th/Nb, Th/La and Ba/La, suggest the magma originated from lithosphere mantle. The Fo values of olivine and Pd/Ir-Ni/Cu diagram suggest primary magma was High Mg basalt. The laser ablation inductively coupled plasma atomic emission spectroscopy zircon U-Pb age is 641.5 ± 3.7 Ma.
基金funded by a "Chinese NSF" Project (41272114) to Xingchun Zhanga "CAS Western Light Talent Culture" Project to Chengbiao Lenga "CAS Hundred Talents" Project to Jianfeng Gao
文摘The Kukaazi Pb-Zn-Cu-W polymetallic deposit, located in the Western Kunlun orogenic belt, is a newly discovered skarn-type deposit. Ore bodies mainly occur in the forms of lenses and veins along beddings of the Mesoproterozoic metamorphic rocks. Three ore blocks, KⅠ,KⅡ, and KⅢ, have been outlined in different parts of the Kukaazi deposit in terms of mineral assemblages. The KⅠ ore block is mainly composed of chalcopyrite, scheelite,pyrrhotite, sphalerite, galena and minor pyrite, arsenopyrite,and molybdenite, whereas the other two ore blocks are made up of galena, sphalerite, magnetite and minor arsenopyrite and pyrite. In this study, we obtained a molybdenite isochron Re–Os age of 450.5 ± 6.4 Ma(2σ,MSWD = 0.057) and a scheelite Sm–Nd isochron age of 426 ± 59 Ma(2σ, MSWD = 0.49) for the KⅠ ore block.They are broadly comparable to the ages of granitoid in the region. Scheelite grains from the KⅠ ore block contain high abundances of rare earth elements(REE, 42.0–95.7 ppm)and are enriched in light REE compared to heavy REE, with negative Eu anomalies(δEu = 0.13–0.55). They display similar REE patterns and Sm/Nd ratios to those of the coeval granitoids in the region. Moreover, they also have similar Sr and Nd isotopes [ ^(87)Sr/ ^(86)Sr = 0.7107–0.7118;ε_(Nd)(t) =-4.1 to-4.0] to those of such granitoids, implying that the tungsten-bearing fluids in the Kukaazi deposit probably originate from the granitic magmas. Our results first defined that the Early Paleozoic granitoids could lead to economic Mo–W–(Cu) mineralization at some favorable districts in the Western Kunlun orogenic belt and could be prospecting exploration targets.
文摘Kupferschiefer type Cu-Ag deposits occur in the Upper Permian Xuanwei Formation in the Leshan-Muchuan region at the southwestern edge of the Sichuan Basin. Evidences from geology, major element, REE and thermolurninescence analyses suggest that these Kupferschiefer type CuAg deposits were formed during diagenesis and the ore-forming fluids were derived frorn the underlying basalt. Fluid dynamic analyses show that the ore-forming fluids migrated in a unicellular convection, fluids migrated through the basalt, leaching Cu and Ag frorn basalt and forming orebearing solutions, up the western basement highs, moved laterally along the Xuanwei Formation toward the basin centers, presumably to sink back down into the basalt, completing a convection cycle which was about 15 km long, 300 m high and subhorizontal. Further analysis and calculation suggest that there are good geological, tectonic and fluid-dynamic conditions to form middle-scale Cu and giant Ag Kupferschiefer type deposits, but superlarge deposits are unlikely to be formed in this region.
基金supported jointly by the Major Orientation Research Project (No. KZCX2-YW-111) of CASNational Basic Research Program of China (No. 2007CB411408)the National Natural Science Foundation of China (No. 40872074)
文摘The Bainiuchang deposit in Yunnan Province, China, is located geographically between the Gejiu ore field and the Dulong ore field. In addition to >7000 t Ag reserves, the deposit possesses large-scale Pb, Zn, Sn reserves and a mass of dispersed elements (i.e., In, Cd, Ge, Ga, etc.). Based on systematic studies of sulfur isotopic composition, the authors conclude: The Bainiuchang deposit experienced two epochs of metallogenesis, i.e., the Middle-Cambrian sea-floor exhalative sedimentary metallogenic epoch and the Yanshanian magmatic hydrothermal superimposition metallogenic epoch. In the two metallogenic epochs, the δ34S values of sulfides were all near 0, showing a tendency of being enriched slightly in heavy sulfur. The δ34S values of sulfides in the early metallogenic epoch are within the range of 2‰–5‰ with a peak value range of 2‰–3‰ and an average of 3.0‰, and those of sulfides in the late metallogenic epoch are within the range of 2‰–6‰ with a peak value of 3‰–4‰ and an average of 3.9‰. For the single metallogenic epoch, sulfur in the ore-forming fluids in the early epoch already reached isotopic equilibrium and was derived mainly from underneath the magma chamber or basement metamorphic igneous rocks. Sulfur in the sulfides in the late epoch was derived mainly from magmatic hydrothermal fluids formed in the process of remelting of the basement metamorphic igneous rocks.
基金ThisresearchprojectwasfinanciallysupportedjointlybytheNationalNaturalScienceFoundationofChina (No .96 914 0 3)andtheImportantProjectsundertheKnowledge InnovationProgramsponsoredbytheChineseAcademyofSciences (No.KZCX2 SW 117)
文摘In terms of major element, trace element and REE geochemical characteristics of volcanic rocks in the area studied and by making use of the TiO\-2\|K\-2O\|P\-2O\-5, Th\|Hf\|Ta and Zr\|Nb\|Y trianglar diagrams and the environmental discrimination diagrams of incompatible element distribution patterns, the authors have drawn some conclusions that are different from those by previous workers. It is concluded that volcanic rocks in the Laochang Ag polymetallic deposit at Lancang, Yunnan belong to continental within\|plate alkali basalts, and that their geotectonic setting seems to be at the northeastern margin of East Gondwana Land.
