The Pulang (普朗) porphyry copper deposit, located in the southern segment of the Yidun-Zhongdian (义敦-中甸) island arc ore-forming belt of the Tethys-Himalaya ore-forming domain, is a recently discovered large c...The Pulang (普朗) porphyry copper deposit, located in the southern segment of the Yidun-Zhongdian (义敦-中甸) island arc ore-forming belt of the Tethys-Himalaya ore-forming domain, is a recently discovered large copper deposit. Compared with the composition of granodiorite in China, the porphyry rocks in this area are enriched in W, Mo, Cu, Au, As, Sb, F, V, and Na2O (K1≥1.2). Compared with the composition of fresh porphyry rocks in this district, the mineralized rocks are enriched in Cu, Au, Ag, Mo, Pb, Zn, W, As, Sb, and K2O (K2≥1.2). Some elements show clear anomalies, such as Zn, Ag, Cu, Au, W, and Mo, and can be regarded as pathfinders for prospecting new ore bodies in depth. It has been inferred from factor analysis that the Pulang porphyry copper deposit may have undergone the multiple stages of alteration and mineralization: (a) Cu-Au mineralization; (b) W-Mo mineralization; and (c) silicification and potassic metasomatism in the whole ore-forming process. A detailed zonation sequence of indicator elements is obtained using the variability index of indicator elements as follows: Zn→Ag→Cu→Au→W→Mo. According to this zonation, an index such as (Ag*Zn)D/(Mo×W)D can be constructed and regarded as a significant criterion for predicting the Cu potential at a particular depth.展开更多
The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also refe...The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also referred to as the Pulang deposit)in this area has proven copper reserves of 5.11×106 t.This deposit has been exploited on a large scale using advanced mining methods,exhibiting substantial economic benefit.Based on many research results of previous researchers and the authors’team,this study proposed the following key insights.(1)The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring.This understanding was overturned in this study.Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc,and the mineralization is mainly related to the magmatism of quartz monzonite porphyries.(2)Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit.Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone.Most of them have developed in the potassium silicate alteration zone.The main orebody occurs as large lenses at the top of the hanging wall of rock bodies,with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m(average:187.07 m).It has a copper grade of 0.21%-1.56%(average:0.42%)and proven copper resources of 5.11×10^(6) t,which are associated with 113 t of gold,1459 t of silver,and 170×10^(3) t of molybdenum.(3)Many studies on diagenetic and metallogenic chronology,isotopes,and fluid inclusions have been carried out for the Pulang deposit,including K-Ar/Ar-Ar dating of monominerals(e.g.,potassium feldspars,biotites,and amphiboles),zircon U-Pb dating,and molybdenite Re-Os dating.The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites,quartz monzonite porphyries formed during the mineralization,and post-mineralization granite porphyries,which were formed at 223±3.7 Ma,218±4 Ma,and 207±3.9 Ma,respectively.The metallogenic age of the Pulang deposit is 213‒216 Ma.(4)The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites.The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity.The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust-and mantle-derived magmas.展开更多
1 Introduction The eastern Tianshan region covers around 60000 km2in area and is located in the eastern part of Xinjiang.The district contains various types mineral commodities including Cu,Ni,Au,Fe,Pb and Zn(Wang et ...1 Introduction The eastern Tianshan region covers around 60000 km2in area and is located in the eastern part of Xinjiang.The district contains various types mineral commodities including Cu,Ni,Au,Fe,Pb and Zn(Wang et al.,2006).The Dannanhu belt in eastern part of the area is interpreted as a volcanic arc and forms an important mineralized zone bordered by the Turpan-Hami Basin to the north and Kanggur back-arc basin to the south.展开更多
In accordance with the terms global minerogenic series, regional metallogenic series and ore depositsystem which are put forward here, metallogenic environments at different levels are discussed for theporphyry copper...In accordance with the terms global minerogenic series, regional metallogenic series and ore depositsystem which are put forward here, metallogenic environments at different levels are discussed for theporphyry copper deposit series in China. It is considered that the porphyry copper deposits in China arecontrolled not only by the boundaries of convergent plates but, more importantly, by the boundaries ofintraplate divergent mobile belts and those between continental blocks. Besides, the emplacement ofhypabyssal and supper-hypabyssal calc-alkaline magmas and the temporal-spatial distribution of China'sporphyry copper deposits are governed by the superimposition of fracture systems of the pre-Alpine base-ments. Meso-Cenozoic cover and continental-margin new-born crust. Such a superimposition has also re-sulted in the polycyclicity of the mineralization.展开更多
Objective The post-ore modification and preservation of porphyry copper deposits is controlled and influenced by various geological processes, and the regional uplift and denudation is the most important factors. Thi...Objective The post-ore modification and preservation of porphyry copper deposits is controlled and influenced by various geological processes, and the regional uplift and denudation is the most important factors. This study used biotite mineral geobarometer and Apatite Fission Track (AFT) to restore the uplift evolution of the granitic porphyries in the Geza arc and to obtain quantitative data of rock erosion degree and denudation rate.展开更多
1 Introduction 1The Sanjiang region in SE Tibet Plateau and NW Yunnan is known to have formed by amalgamation of Gongwanaderived continental blocks and arc terranes as a result of oceanic subduction followed by contin...1 Introduction 1The Sanjiang region in SE Tibet Plateau and NW Yunnan is known to have formed by amalgamation of Gongwanaderived continental blocks and arc terranes as a result of oceanic subduction followed by continental展开更多
Extending in a NNW-SSE direction. the Yulong porphyry copper belt is the largest and richest porphyry copper belt in China, originating in the Paleogene. Tectonically located on the eastern margin of the northern Tibe...Extending in a NNW-SSE direction. the Yulong porphyry copper belt is the largest and richest porphyry copper belt in China, originating in the Paleogene. Tectonically located on the eastern margin of the northern Tibet geodepression. and nearly 500 km of the Himalayan Yarlung Zangbo plate subduction zone of nearly E-W trend. it is a relatively typical intracontinental rejuvenated platform-type porphyry copper belt. Ore-bearing porphyry masses in the belt mainly represented by monzogranite-porphyry occurring as stocks in variegated sandshale of the lower Upper Triassic Jiapila Fromation and its overlying and underlying copper-bearing strata. They are characterized by enrichment in K. CI and LREE. abundant fluid inclusions and a distinct porphyroblastic texture. The oxygen. hydrogen. strotium. lead and sulfur isotopic values of the rock show the feature of crust-mantle mixing.The Orebodies are plpe-shaped stratoid; the mineralization is dominated by Cu and Mo, accompanied by Fe. Co. Au. Ag. Bi. W. Pb. Zn. and Pt-group elements. Alteration is strong. marked mainly by potassic alteration, silicification. skarnization and propylitization. The formation of this type of deposit largely progressed through two stages. The first stage was the stage of formation of Cu-bearing source beds. It occurred in the Triassic. when a transgressive copper-bearing formation was deposited on the western margin of the Qamdo Bay. which was represented by intermediate-acid volcanic rocks and variegated sandshale in the lower part. dolomitic carbonate rocks in the middle and black carbonaceous sandshale in the upper part. In the second stage. composite porphyry copper deposits were formed. This stage took place in the Paleogene. when this district was in a stage of platform rejuvenation. forming a series of NNW-trending deep faults. so that Na, K. Cl. H2O and CO2-rich hydrothermal fluids from the depths were injected into the upper crust and replaced and melted copper-bearing sialic rocks of the upper crust. e. g. the Triassic copper-bearing rock series in the Yulong area. to form porphyroblastic cooper-bearing intermediate-acid porphyry.展开更多
The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± ...The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± 1.6 Ma. Geochemically, the rock is rich in alkalis (especially sodium), light rare earth elements (LREE) and large-ion lithophile elements (LILE), and has a relatively low initial strontium isotopic ratio (Isr=0.7058); thus it is the product of differentiation of crust-mantle mixing source magma. The model of alteration and mineralization zoning is similar to the Hollister (1974) diorite model. The ore fluids have a relatively high salinity and contain significant amounts of CO2, Ca2+, Na+ and ***CI?. The homogenization temperatures of fluid inclusions for the main mineralization stage range from 280 to 420°C, the δ18O values of the ore fluids vary from 3.51 to 5.52 %, the δD values are in the range between ?82.4 and ?59.8 %, the δ34S values of sulphides vary from ?0.3 to 2.49 %, and the δ13C values of CO2 in inclusions range between ?2.66 and ?6.53 %. Isotope data indicate that the hydrothermal ore fluids and ore substances of the Shaxi porphyry copper (gold) deposits were mainly derived from magmatic systems.展开更多
The Yulong supper\|large copper deposit is situated within the well\|known S\|N striking Yulong copper\|molybdenum ore belt. The ore\|bearing biotite\|monogranitic porphyry was emplaced within clastic rocks (mainly sh...The Yulong supper\|large copper deposit is situated within the well\|known S\|N striking Yulong copper\|molybdenum ore belt. The ore\|bearing biotite\|monogranitic porphyry was emplaced within clastic rocks (mainly shales and siltstones) of the Jiapila Formation (T 3 j ) and carbonate rocks of the Bolila Formation (T 3 b ) of the Upper Triassic. Five mineralization patterns have been recognized in the deposit, i.e., ①veinlet\|disseminated Cu\|Mo ore in the porphyry; ②skarn\|type Cu ore at the contact zone with carbonates (T 3 b ); ③stratiform\|like oxidized Cu ore between T 3 b carbonate rocks and T 3 j hornstones; ④brecciated Cu ore at the local periphery of porphyry; and ⑤vein Pb\|Zn\|Ag ore in the outer contact zone. They constitute a unique integrated polymetal mineralization series of epigenetic intermediate\|acid magmatic hydrothermal system.Studies have shown that the Yulong deposit was the coupling product of sedimentation, magmatism, and tectonism. The Cu\|bearing sandstones in the Japila Formation have provided partial ore\|bearing materials for the porphyry mineralization during the Himalayan period. The mineralized porphyry mass was passively emplaced and controlled by a nose\|like anticlinal trap opening to the north. The interlayered fractured zone formed during folding between the Jiapila and Bolila Formations acted as favorable host space for stratiform\|like skarn and oxidized ores. A large number of cleavages and fissures developed during folding provided both conduits for the circulation of ore\|forming fluids and host spaces for Pb\|Zn\|Ag ore veins. The veinlet\|disseminated Cu\|Mo ore in the porphyry mass owns the characteristics of typical porphyry copper deposits in the world. The veinlet\|disseminated ore body and the stratiform\|like skarn\|type and/or oxidized ore body, the two main ore bodies in Yulong, are connected with each other and shown as “mushroom\|like" shape, in which the former occurs as “mushroom stem" and the latter as “mushroom cover".展开更多
基金supported by the National High Technology Research and Development Program of China (No 2006AA06Z113)the National Natural Science Foundation of China (No. 40772197)
文摘The Pulang (普朗) porphyry copper deposit, located in the southern segment of the Yidun-Zhongdian (义敦-中甸) island arc ore-forming belt of the Tethys-Himalaya ore-forming domain, is a recently discovered large copper deposit. Compared with the composition of granodiorite in China, the porphyry rocks in this area are enriched in W, Mo, Cu, Au, As, Sb, F, V, and Na2O (K1≥1.2). Compared with the composition of fresh porphyry rocks in this district, the mineralized rocks are enriched in Cu, Au, Ag, Mo, Pb, Zn, W, As, Sb, and K2O (K2≥1.2). Some elements show clear anomalies, such as Zn, Ag, Cu, Au, W, and Mo, and can be regarded as pathfinders for prospecting new ore bodies in depth. It has been inferred from factor analysis that the Pulang porphyry copper deposit may have undergone the multiple stages of alteration and mineralization: (a) Cu-Au mineralization; (b) W-Mo mineralization; and (c) silicification and potassic metasomatism in the whole ore-forming process. A detailed zonation sequence of indicator elements is obtained using the variability index of indicator elements as follows: Zn→Ag→Cu→Au→W→Mo. According to this zonation, an index such as (Ag*Zn)D/(Mo×W)D can be constructed and regarded as a significant criterion for predicting the Cu potential at a particular depth.
基金jointly funded by the national key research and development program project“Strategic Mineral Information and Metallogenic Regularity of the Tethyan Metallogenic Domain”(2021YFC2901803)a project of the National Natural Science Foundation of China entitled“Geological Structure Mapping and Regional Comparative Study of the Tethyan Tectonic Domain”(92055314),International Geoscience Programme(IGCP-741)a project initiated by the China Geological Survey(DD20221910).
文摘The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also referred to as the Pulang deposit)in this area has proven copper reserves of 5.11×106 t.This deposit has been exploited on a large scale using advanced mining methods,exhibiting substantial economic benefit.Based on many research results of previous researchers and the authors’team,this study proposed the following key insights.(1)The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring.This understanding was overturned in this study.Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc,and the mineralization is mainly related to the magmatism of quartz monzonite porphyries.(2)Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit.Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone.Most of them have developed in the potassium silicate alteration zone.The main orebody occurs as large lenses at the top of the hanging wall of rock bodies,with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m(average:187.07 m).It has a copper grade of 0.21%-1.56%(average:0.42%)and proven copper resources of 5.11×10^(6) t,which are associated with 113 t of gold,1459 t of silver,and 170×10^(3) t of molybdenum.(3)Many studies on diagenetic and metallogenic chronology,isotopes,and fluid inclusions have been carried out for the Pulang deposit,including K-Ar/Ar-Ar dating of monominerals(e.g.,potassium feldspars,biotites,and amphiboles),zircon U-Pb dating,and molybdenite Re-Os dating.The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites,quartz monzonite porphyries formed during the mineralization,and post-mineralization granite porphyries,which were formed at 223±3.7 Ma,218±4 Ma,and 207±3.9 Ma,respectively.The metallogenic age of the Pulang deposit is 213‒216 Ma.(4)The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites.The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity.The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust-and mantle-derived magmas.
基金financially supported by Chinese National Basic Research 973 Program(2014CB440803)the National Natural Science Foundation of China(41572077)China Geological Survey Bureau(12120114065801,121201001000150010 and 121201004000150017-43)
文摘1 Introduction The eastern Tianshan region covers around 60000 km2in area and is located in the eastern part of Xinjiang.The district contains various types mineral commodities including Cu,Ni,Au,Fe,Pb and Zn(Wang et al.,2006).The Dannanhu belt in eastern part of the area is interpreted as a volcanic arc and forms an important mineralized zone bordered by the Turpan-Hami Basin to the north and Kanggur back-arc basin to the south.
文摘In accordance with the terms global minerogenic series, regional metallogenic series and ore depositsystem which are put forward here, metallogenic environments at different levels are discussed for theporphyry copper deposit series in China. It is considered that the porphyry copper deposits in China arecontrolled not only by the boundaries of convergent plates but, more importantly, by the boundaries ofintraplate divergent mobile belts and those between continental blocks. Besides, the emplacement ofhypabyssal and supper-hypabyssal calc-alkaline magmas and the temporal-spatial distribution of China'sporphyry copper deposits are governed by the superimposition of fracture systems of the pre-Alpine base-ments. Meso-Cenozoic cover and continental-margin new-born crust. Such a superimposition has also re-sulted in the polycyclicity of the mineralization.
基金financially supported by the National Natural Science Foundation of China(Grant No.41502076)the National Basic Research Program of China(973 Program)(Grant No.2015CB4526056)
文摘Objective The post-ore modification and preservation of porphyry copper deposits is controlled and influenced by various geological processes, and the regional uplift and denudation is the most important factors. This study used biotite mineral geobarometer and Apatite Fission Track (AFT) to restore the uplift evolution of the granitic porphyries in the Geza arc and to obtain quantitative data of rock erosion degree and denudation rate.
基金financially supported by the Open Funds of Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry (Grant No. GLMPM-009)the Open Funds of State Key Laboratory of Ore Deposit Geochemistry (Grant No. 201505)
文摘1 Introduction 1The Sanjiang region in SE Tibet Plateau and NW Yunnan is known to have formed by amalgamation of Gongwanaderived continental blocks and arc terranes as a result of oceanic subduction followed by continental
文摘Extending in a NNW-SSE direction. the Yulong porphyry copper belt is the largest and richest porphyry copper belt in China, originating in the Paleogene. Tectonically located on the eastern margin of the northern Tibet geodepression. and nearly 500 km of the Himalayan Yarlung Zangbo plate subduction zone of nearly E-W trend. it is a relatively typical intracontinental rejuvenated platform-type porphyry copper belt. Ore-bearing porphyry masses in the belt mainly represented by monzogranite-porphyry occurring as stocks in variegated sandshale of the lower Upper Triassic Jiapila Fromation and its overlying and underlying copper-bearing strata. They are characterized by enrichment in K. CI and LREE. abundant fluid inclusions and a distinct porphyroblastic texture. The oxygen. hydrogen. strotium. lead and sulfur isotopic values of the rock show the feature of crust-mantle mixing.The Orebodies are plpe-shaped stratoid; the mineralization is dominated by Cu and Mo, accompanied by Fe. Co. Au. Ag. Bi. W. Pb. Zn. and Pt-group elements. Alteration is strong. marked mainly by potassic alteration, silicification. skarnization and propylitization. The formation of this type of deposit largely progressed through two stages. The first stage was the stage of formation of Cu-bearing source beds. It occurred in the Triassic. when a transgressive copper-bearing formation was deposited on the western margin of the Qamdo Bay. which was represented by intermediate-acid volcanic rocks and variegated sandshale in the lower part. dolomitic carbonate rocks in the middle and black carbonaceous sandshale in the upper part. In the second stage. composite porphyry copper deposits were formed. This stage took place in the Paleogene. when this district was in a stage of platform rejuvenation. forming a series of NNW-trending deep faults. so that Na, K. Cl. H2O and CO2-rich hydrothermal fluids from the depths were injected into the upper crust and replaced and melted copper-bearing sialic rocks of the upper crust. e. g. the Triassic copper-bearing rock series in the Yulong area. to form porphyroblastic cooper-bearing intermediate-acid porphyry.
文摘The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± 1.6 Ma. Geochemically, the rock is rich in alkalis (especially sodium), light rare earth elements (LREE) and large-ion lithophile elements (LILE), and has a relatively low initial strontium isotopic ratio (Isr=0.7058); thus it is the product of differentiation of crust-mantle mixing source magma. The model of alteration and mineralization zoning is similar to the Hollister (1974) diorite model. The ore fluids have a relatively high salinity and contain significant amounts of CO2, Ca2+, Na+ and ***CI?. The homogenization temperatures of fluid inclusions for the main mineralization stage range from 280 to 420°C, the δ18O values of the ore fluids vary from 3.51 to 5.52 %, the δD values are in the range between ?82.4 and ?59.8 %, the δ34S values of sulphides vary from ?0.3 to 2.49 %, and the δ13C values of CO2 in inclusions range between ?2.66 and ?6.53 %. Isotope data indicate that the hydrothermal ore fluids and ore substances of the Shaxi porphyry copper (gold) deposits were mainly derived from magmatic systems.
文摘The Yulong supper\|large copper deposit is situated within the well\|known S\|N striking Yulong copper\|molybdenum ore belt. The ore\|bearing biotite\|monogranitic porphyry was emplaced within clastic rocks (mainly shales and siltstones) of the Jiapila Formation (T 3 j ) and carbonate rocks of the Bolila Formation (T 3 b ) of the Upper Triassic. Five mineralization patterns have been recognized in the deposit, i.e., ①veinlet\|disseminated Cu\|Mo ore in the porphyry; ②skarn\|type Cu ore at the contact zone with carbonates (T 3 b ); ③stratiform\|like oxidized Cu ore between T 3 b carbonate rocks and T 3 j hornstones; ④brecciated Cu ore at the local periphery of porphyry; and ⑤vein Pb\|Zn\|Ag ore in the outer contact zone. They constitute a unique integrated polymetal mineralization series of epigenetic intermediate\|acid magmatic hydrothermal system.Studies have shown that the Yulong deposit was the coupling product of sedimentation, magmatism, and tectonism. The Cu\|bearing sandstones in the Japila Formation have provided partial ore\|bearing materials for the porphyry mineralization during the Himalayan period. The mineralized porphyry mass was passively emplaced and controlled by a nose\|like anticlinal trap opening to the north. The interlayered fractured zone formed during folding between the Jiapila and Bolila Formations acted as favorable host space for stratiform\|like skarn and oxidized ores. A large number of cleavages and fissures developed during folding provided both conduits for the circulation of ore\|forming fluids and host spaces for Pb\|Zn\|Ag ore veins. The veinlet\|disseminated Cu\|Mo ore in the porphyry mass owns the characteristics of typical porphyry copper deposits in the world. The veinlet\|disseminated ore body and the stratiform\|like skarn\|type and/or oxidized ore body, the two main ore bodies in Yulong, are connected with each other and shown as “mushroom\|like" shape, in which the former occurs as “mushroom stem" and the latter as “mushroom cover".