The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristi...The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.展开更多
Based upon a comprehensive study of 123 copper deposits in China. this paper reaches the following conclusions: 1. The crust in China was solidified pretty late; with the accretion of the plate, the copper mineralizat...Based upon a comprehensive study of 123 copper deposits in China. this paper reaches the following conclusions: 1. The crust in China was solidified pretty late; with the accretion of the plate, the copper mineralization moved towards its margin in space and became successively younger in age. 2. The major copper ore types ever found in the world have mostly been discovered in China, in which the porphyry type seems to be the most important and the massive sulfide type in the transitional bed between marine clastic and carbonate rocks is clearly defined. 3. Carbonate strata are widespread in China and their deposition lasted for a long geological period, so the proportion of copper deposits occurring in them is large as compared with other parts of the world. 4. Seven metallogenic epochs can be recognized, in which the Mesozoic one plays the leading role and the middle(late) Palaeozoic and Cenozoic ones are next in importance. Mineralization was comparatively simple in the early geological period. and became diversified later on. In the early epochs copper deposits related to basaltic magmatism and metamorphosed marine sediments predominated, whereas in the later epochs those related to granitic magmatism and continental sedimentation were dominant. 5. There exist in China thirteen metallogenic provinces, of which the Lower Yangtze downwarping belt, Sanjiang fold system, Jiangnan axis and Xikang-Yunnan axis are of greater significance. 6. The crustal mobility in China was rather pronounced, the polycyclic evolution of the crust has resulted in such obvious phenomena as the inheritance of mineralization, the coexistence of various types and the superposition of different genetic types.展开更多
1 Introduction Sareke glutenite-type copper deposit is the large size copper deposit discovered in recent years,and it is located Sarekebayi intracontinental pull-apart basin in the western margin of the Tarim basin.C...1 Introduction Sareke glutenite-type copper deposit is the large size copper deposit discovered in recent years,and it is located Sarekebayi intracontinental pull-apart basin in the western margin of the Tarim basin.Conglomerate of展开更多
Studies on organic geochemistry indicate that the origin, type and maturity of organic matter are different among coal-bearing, copper-bearing and evaporite formations in the Mesozoic continental Chuxiong Basin, Yunna...Studies on organic geochemistry indicate that the origin, type and maturity of organic matter are different among coal-bearing, copper-bearing and evaporite formations in the Mesozoic continental Chuxiong Basin, Yunnan, China. A mechanism has been proposed that (1) during the diagenetic mineralization stage the short-chain organic acids dervied from kerogen played an important role in remobilizing copper from source beds, while oils acted as important carrier of copper, and that (2) during the transformation or remolding mineralization stage, meteoric water leached the evaporite layers and formed downward-percolating oxidizing SO42-rich fluids; meanwhile, the copper-bearing fluids migrating upwards along growth faults from the basement was contaminated by the coal-bearing series on the way and formed reducing organic-rich fluids; oxidation-reduction occurred and sulfides formed when the two kinds of fluids met within sandstones.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 metallogenesis of subvolcanic deposits is controlled by subvolcanic activities. The copper polymetallic deposits are genetically related to intermediate-acid rocks, and the silver polymetallic deposits are more cl...The metallogenesis of subvolcanic deposits is controlled by subvolcanic activities. The copper polymetallic deposits are genetically related to intermediate-acid rocks, and the silver polymetallic deposits are more closely related to acid rocks. The abundance of Cu is relatively high in the intermediate-acid rocks and subvolcanic rocks, whereas the abundances of Pb, An and Ag are high in acid rocks, indicating rich ore-forming elements in original magmas. The study of REEs shows that the magmatic type related to copper deposits is the syntectic type, and that related to silver polymetallic deposits is mainly the re-melting type. The deposits were formed under medium-low temperatures and low salinity. The metallogenic times were the late stage of the early Yanshanian or the late Yanshanian, dating 78–147 Ma.展开更多
Platinum-group elements (PGE) in PGE-rich porphyry copper (gold) deposits are mainly Pt and Pd, whereas the concentrations of other PGE (Ru, Rh, Os, Ir) are significantly low. Moreover, Pt and Pd mainly exist in...Platinum-group elements (PGE) in PGE-rich porphyry copper (gold) deposits are mainly Pt and Pd, whereas the concentrations of other PGE (Ru, Rh, Os, Ir) are significantly low. Moreover, Pt and Pd mainly exist in sulfides in the forms of crystal lattice or tiny platinum-group mineral (PGM) inclusions. The present data show that there is a positive relationship between Pt and Pd concentrations and Cu (Au) in porphyry copper (gold) deposits. The comparison of chondrite-normalized PGE distribution patterns between the ore-bearing porphyry intrusions and ore-barren porphyry intrusions in arc setting, 187^Os/188^Os, 87^Sr/86^Sr and S isotopes for porphyry copper (gold) deposits shows that PGEs were mainly derived from the mantle, and fluids from subduction zones devoted trivial PGE to the magma. The porphyry copper (gold) deposits associated with subducted events are most probably enriched in PGE, whereas those related to crustal thickening, lithospheric delamination or underplating rarely concentrate PGE. The osmium isotopic compositions in porphyry copper (gold) deposits reveal that (187^Os/188^Os)i values are highly variable and not lower than those of primitive upper mantle (PUM) and mantle peridotite, however, osmium concentrations are commonly lower than mantle peridotite, suggesting that parental magmas of some porphyry intrusions had experienced crustal contamination during magma evolution. Experimental investigations have proved that PGE exist in the forms of Cl^- and HS^- complexes during transportation and migration of the oreforming fluids. This paper summarizes previous studies including crucial controlling factors and mechanisms for PGE enrichment, and points out that the mantle-derived magmas parental to porphyry intrusions are the prerequisite for PGE enrichment in porphyry copper (gold) deposits. Favorable physical and chemical conditions (including salinity, temperature, pressure, pH, and oxygen fugacity) in hydrothermal fluids crucially control the PGE enrichment, and sulfur concentrations of melts play important roles in this process as well.展开更多
The middle south parts of Tancheng Lujiang deep fault zone and its vicinity are an important locality of Cu Au deposits related to Mesozoic volcanic subvolcanic magmatism in eastern China. According to their metal...The middle south parts of Tancheng Lujiang deep fault zone and its vicinity are an important locality of Cu Au deposits related to Mesozoic volcanic subvolcanic magmatism in eastern China. According to their metallogenic features and ore forming conditions, copper gold deposits in this district are ascribed to two groups: the epithermal group which can be further divided into tellurium gold type, quartz adularia type and quartz manganoansiderite type; the magmatic hydrothermal group which includes porphyry Cu Au deposit, breccia pipe porphyry type Au Cu deposit and skarn type Au Cu deposit. In this paper, characteristics of six typical shoshonite hosted Cu Au deposits are outlined. Additionally, the factors that control the metallogenesis and distribution of these Cu Au deposits are discussed preliminarily.展开更多
The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural...The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural trap. The mechanism has three major features: (1) timing of mineralization; (2) positioning of hostformation; and (3) dependence of ore-controlling structure on properties of rocks. The 'optimum surface' is adivisional structural plane which marks obvious difference in physical, chemical and mechanical properties andis favorable for mineralization. It is also a unity of structures. lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the ma-jor characteristic clements in the ore-controlling fault belt: elements with a small radius (Si, Fe, Mg and Al)moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remotefrom the center.展开更多
Jiama,with more than 11 Mt of copper metal,is the largest porphyry-skarn copper system in the Gangdese metallogenic belt,Tibet,China,creating ideal conditions for deciphering the origin of porphyry ores in a collision...Jiama,with more than 11 Mt of copper metal,is the largest porphyry-skarn copper system in the Gangdese metallogenic belt,Tibet,China,creating ideal conditions for deciphering the origin of porphyry ores in a collision setting.Despite massive studies of the geology,chronology,petrogenesis,and ore-related fluids and their sources in Jiama,there is a lack of systematic summaries and reviews of this system.In contrast to traditional porphyry copper systems in a subduction setting,recent studies and exploration suggest that the Jiama deposit includes porphyry-type Mo-Cu,skarn-type Cu polymetallic,vein-type Au and manto orebodies.This paper reviews the latest studies on the geology,chronology,petrogenesis,fluid inclusions,and isotopic geochemistry(hydrogen,oxygen,sulfur,and lead)of the Jiama deposit.Accordingly,a multi-center complex mineralization model was constructed,indicating that multi-phase intrusions from the same magma reservoir can form multiple hydrothermal centers.These centers are mutually independent and form various orebodies or are superimposed on each other and form thick,high-grade orebodies.Finally,a new comprehensive exploration model was established for the Jiama porphyry copper system.Both models established in this study help to refine the theories on continental-collision metallogeny and porphyry copper systems.展开更多
The Jiama porphyry copper deposit in Tibet is one of the proven supergiant copper deposits in the Qinghai-Tibet Plateau at present,with the reserves of geological resources equivalent to nearly 20×10^(6) t.Howeve...The Jiama porphyry copper deposit in Tibet is one of the proven supergiant copper deposits in the Qinghai-Tibet Plateau at present,with the reserves of geological resources equivalent to nearly 20×10^(6) t.However,it features wavy and steep terrain,leading to extremely difficult field operation and heavy interference.This study attempts to determine the effects of the tensor controlled-source audiomagnetotellurics(CSAMT)with high-power orthogonal signal sources(also referred to as the high-power tensor CSAMT)when it is applied to the deep geophysical exploration in plateaus with complex terrain and mining areas with strong interference.The test results show that the high current provided by the highpower tensor CSAMT not only greatly improved the signal-to-noise ratio but also guaranteed that effective signals were received in the case of a long transmitter-receiver distance.Meanwhile,the tensor data better described the anisotropy of deep geologic bodies.In addition,the tests also show that when the transmitting current reaches 60 A,it is still guaranteed that strong enough signals can be received in the case of the transmitter-receiver distance of about 25 km,sounding curves show no near field effect,and effective exploration depth can reach 3 km.The 2D inversion results are roughly consistent with drilling results,indicating that the high-power tensor CSAMT can be used to achieve nearly actual characteristics of underground electrical structures.Therefore,this method has great potential for application in deep geophysical exploration in plateaus and mining areas with complex terrain and strong interference,respectively.This study not only serves as important guidance on the prospecting in the Qinghai-Tibet Plateau but also can be used as positive references for deep mineral exploration in other areas.展开更多
The Lut block, eastern Iran, is one of the most extensive Cenozoic magmatic rocks, that show suitable targets for porphyry Cu-Au and high-sulfidation epithermal Au related to porphyry Cu-Au mineralization. In this stu...The Lut block, eastern Iran, is one of the most extensive Cenozoic magmatic rocks, that show suitable targets for porphyry Cu-Au and high-sulfidation epithermal Au related to porphyry Cu-Au mineralization. In this study, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was used to identify different erosion levels of three porphyry Cu deposits, including Maherabad, Shadan, and Chah Shaljami, located in the Lut block volcanic-plutonic belt. Alteration minerals, including kaolinite, dickite, alunite, jarosite, epidote, chlorite, montmorillonite, muscovite, biotite, orthoclase, gypsum, and quartz, are selected to map different alteration zones and erosion levels. Distributions of end-members are mapped by using the SAM and MTMF in VNIR and SWIR of ASTER bands and the results are evaluated against the field studies. For some end-members, the results of SAM processing are more reliable compared to the MTMF because the latter looses field spectra. The use of angle threshold in the SAM, and MF-score and infeasibility value in the MTMF or low abundance of some end-members, and finally comparison of output images of spectral processing show good correlation with alteration maps. Differentiation and explanation of various erosion levels of porphyry Cu deposits are done successfully by using the ASTER sensor data.展开更多
Tongguanshan copper deposit of Tongling large ore belt is one of the typicalskarn copper deposits. Based on careful observation under microscope many daughter mineralsincluding transparent ones and opaque ones have be...Tongguanshan copper deposit of Tongling large ore belt is one of the typicalskarn copper deposits. Based on careful observation under microscope many daughter mineralsincluding transparent ones and opaque ones have been distinguished in the fluid inclusions of garnetand diopside. The results of SEM/EDS (scanning electron microscope/energy dispersive spectrometer)and LRM (laser Raman microprobe) analysis show that these daughter minerals in garnet are sylvite,halite, sphalerite, chalcopyrite and carbonate. Sylvite daughter mineral is very popular in garnetand diopside. The existence of so much sylvite daughter mineral and other daughter minerals in thefluid inclusions indicates that the ore--forming fluid is of supper-high salinity and high potassiumconcentration. High potassium concentration in the fluid inclusions agrees with K-richmesotype--acid rock and K-silicate alteration that occurred widely in this area. The daughtermineral assemblage in garnet and diopside is similar to the mineral assemblage of ore-forming stagethat followed skarn stage.展开更多
This paper describes three main parts of GIS technique used in prospecting of copper deposits. Firstly, this paper briefly introduces GIS technique for data preparation. Then it discusses the geo anomaly (GA) analys...This paper describes three main parts of GIS technique used in prospecting of copper deposits. Firstly, this paper briefly introduces GIS technique for data preparation. Then it discusses the geo anomaly (GA) analysis and targets delineation methods, where the unit ore equivalent calculation of planar GA and the transformation and evaluation of linear GA are dominant. In addition, the method for copper prospecting is demonstrated. Finally a case study of copper deposit prospecting in Yuanjiang, Yunnan Province is presented by the use of MAPGIS.展开更多
The Naruo porphyry copper-gold deposit (hereinafter referred to as the Naruo deposit) in Tibet is a potentially ultra-large, typical gold-rich porphyry copper deposit, which was recently discovered in the Bangongco-...The Naruo porphyry copper-gold deposit (hereinafter referred to as the Naruo deposit) in Tibet is a potentially ultra-large, typical gold-rich porphyry copper deposit, which was recently discovered in the Bangongco-Nujiang metallogenic belt. This study analyzed U-Ph chronology and Hf isotopes of the ore-bearing granodiorite porphyry in the Naruo deposit using the LA-ICPMS dating technique. The results show that the weighted average age is 124.03±0.94Ma (MSWD=1.7, n=20), and 2±6pb/23SU isocbron age is 126.2±2.7 Ma (MSWD=1.02, n=20), both of which are within the error. The weighted average age represents the crystallization age of the granodiorite porphyry, which indicates that the ore-bearing porphyry in the Naruo deposit area was formed in the Early Cretaceous and further implies that the Neo-tethys Ocean had not been closed before 124 Ma under a typical island-arc subduction environment. The εGr(t) of zircons from the granodiorite porphyry varies from 2.14 to 9.07, with an average of 5.18, and all zircons have εRf(t) values greater than 0; 176Hf/177Hf ratio is relatively high (0.282725-0.282986). Combined with the zircon age--Hf isotope correlation diagram, the aforementioned data indicate that the source reservoir might be a region that is mixed with depleted mantle and ancient crust, which possibly contains more materials sourced from depleted mantle. Rock-forming ages and ore-forming ages of the Duolong ore concentrate area are 120-124 Ma and 118-119 Ma, respectively, which indicate 124-118 Ma represents the main rockforming and ore-forming stage within the area. The Naruo deposit is located in the north of the Bangongco-Nujiang suture, and it yielded a zircon LA-ICPMS age of 124.03 Ma. This indicates the Bangongco-Nujiang oceanic basin subducted towards the north at about 124 Ma, and the Neo-tethys Ocean had not been closed before the middle Early Cretaceous. It is possible that the crust-mantle mixing formed the series of large and giant porphyry copper-gold deposits in the Bangongco.展开更多
The Dexing porphyry copper ore mine is located in the Qin-Hang metallogenic belt between the Yangtze block and the Cathaysia block. It is a giant porphyry copper mine in China, including 3 ore districts: Tongchang, F...The Dexing porphyry copper ore mine is located in the Qin-Hang metallogenic belt between the Yangtze block and the Cathaysia block. It is a giant porphyry copper mine in China, including 3 ore districts: Tongchang, Fujiawu and Zhushahong. Our analyses of Re in molybdenite indicate that the ore-forming material of the copper ore deposits in Dexing should be mainly mantle-derived. Our study fills in a gap in the study of formation time of the Dexing copper mine, and further proves that the copper ore deposits in the three ore districts should be formed simultaneously, about 170 Ma, belonging to the early Yanshan period, and that the formation time of the copper ore deposits should be consistent with the formation time of granodiorite porphyry in which the copper ore deposits are hosted. Promising areas for seeking porphyry copper ore deposits is predicated to be the west or southwest of Dexing.展开更多
The Hongshan porphyry-cryptoexplosive breccia type copper deposit occurs in a metamorphic rock series of the Mesoproterozoic Zhongcun Group. Orebodies are distributed inside and outside porphyry-cryptoexplosive brecci...The Hongshan porphyry-cryptoexplosive breccia type copper deposit occurs in a metamorphic rock series of the Mesoproterozoic Zhongcun Group. Orebodies are distributed inside and outside porphyry-cryptoexplosive breccia pipes. The deposit involves five ore-forming types, i.e the porphyry type, cryptoexplosive breccia type, contact-zone veinlet-disseminated type, in-pipe fracture-zone filling-replacement type and out-of-pipe fracture-zone filling-replacement type, forming an ore-forming system of “five ore-forming types within a single rock body”. Fluid inclusion and isotope geochemical studies indicate the following: S, Pb, O and Sr were derived from the lower crust, Nd was derived from the continental crust or depleted mantle and rare earth elements (REE) and trace elements have the crustal source characters; fluids consist dominantly of formation water, metamorphic water and ***meteoric water with a part of magmatic mater, heat came from porphyry while the latter originated from partial melting caused by shear heating in the lower crust and upper mantle. According to its origin the deposit is classified as the hypabyssal and near-surface, meso- and hypothermal copper deposit associated with the late Yanshanian porphyry-cryptoexplosive breccia.展开更多
The geochemical features of REE were studied by comparing the copper ore with the skarn, the diorite and the stratum, to trace the source of metallogenic materials in Anqing copper deposit, Anhui. The origin of metall...The geochemical features of REE were studied by comparing the copper ore with the skarn, the diorite and the stratum, to trace the source of metallogenic materials in Anqing copper deposit, Anhui. The origin of metallogenic hydrothermal fluids was studied through simulating REE pattern of the balanceable hydrothermal fluids. The results indicate that the metallogenic materials come from the diorite and the metallogenic hydrothermal fluids come from the dioritic magma. The results also show that the rare earth elements are relatively mobile during metallization.展开更多
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
基金financially supported by National Natural Science Foundation of China(42272106,41202067)Open Fund of State Key Laboratory for Mineral Deposits Research,Nanjing University(2019-LAMD-K12)China Geological Survey(DD20211386,DD20211392,DD20179603).
文摘The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.
文摘Based upon a comprehensive study of 123 copper deposits in China. this paper reaches the following conclusions: 1. The crust in China was solidified pretty late; with the accretion of the plate, the copper mineralization moved towards its margin in space and became successively younger in age. 2. The major copper ore types ever found in the world have mostly been discovered in China, in which the porphyry type seems to be the most important and the massive sulfide type in the transitional bed between marine clastic and carbonate rocks is clearly defined. 3. Carbonate strata are widespread in China and their deposition lasted for a long geological period, so the proportion of copper deposits occurring in them is large as compared with other parts of the world. 4. Seven metallogenic epochs can be recognized, in which the Mesozoic one plays the leading role and the middle(late) Palaeozoic and Cenozoic ones are next in importance. Mineralization was comparatively simple in the early geological period. and became diversified later on. In the early epochs copper deposits related to basaltic magmatism and metamorphosed marine sediments predominated, whereas in the later epochs those related to granitic magmatism and continental sedimentation were dominant. 5. There exist in China thirteen metallogenic provinces, of which the Lower Yangtze downwarping belt, Sanjiang fold system, Jiangnan axis and Xikang-Yunnan axis are of greater significance. 6. The crustal mobility in China was rather pronounced, the polycyclic evolution of the crust has resulted in such obvious phenomena as the inheritance of mineralization, the coexistence of various types and the superposition of different genetic types.
基金supported by the metallogenic regularities and prediction of glutenite type Cu-Pb-Zn deposit in Tarim west margin(201511016-1)the special mapping techniques and its application demonstration in Sareke overall-exploration area in Xinjiang(12120114081501)
文摘1 Introduction Sareke glutenite-type copper deposit is the large size copper deposit discovered in recent years,and it is located Sarekebayi intracontinental pull-apart basin in the western margin of the Tarim basin.Conglomerate of
基金This study represents the research result of he project supported jointly by the National Natural Science Foundation of China (No. 49173168)the State Key Laboratory of Organic Geochemistry, Chinese Academy of Sciences (OGL-9213)
文摘Studies on organic geochemistry indicate that the origin, type and maturity of organic matter are different among coal-bearing, copper-bearing and evaporite formations in the Mesozoic continental Chuxiong Basin, Yunnan, China. A mechanism has been proposed that (1) during the diagenetic mineralization stage the short-chain organic acids dervied from kerogen played an important role in remobilizing copper from source beds, while oils acted as important carrier of copper, and that (2) during the transformation or remolding mineralization stage, meteoric water leached the evaporite layers and formed downward-percolating oxidizing SO42-rich fluids; meanwhile, the copper-bearing fluids migrating upwards along growth faults from the basement was contaminated by the coal-bearing series on the way and formed reducing organic-rich fluids; oxidation-reduction occurred and sulfides formed when the two kinds of fluids met within sandstones.
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 metallogenesis of subvolcanic deposits is controlled by subvolcanic activities. The copper polymetallic deposits are genetically related to intermediate-acid rocks, and the silver polymetallic deposits are more closely related to acid rocks. The abundance of Cu is relatively high in the intermediate-acid rocks and subvolcanic rocks, whereas the abundances of Pb, An and Ag are high in acid rocks, indicating rich ore-forming elements in original magmas. The study of REEs shows that the magmatic type related to copper deposits is the syntectic type, and that related to silver polymetallic deposits is mainly the re-melting type. The deposits were formed under medium-low temperatures and low salinity. The metallogenic times were the late stage of the early Yanshanian or the late Yanshanian, dating 78–147 Ma.
基金supported by the 12th Five-Year Plan project of State Key Laboratory of Ore Deposit Geochemistry,Chinese Academy of Sciences(SKLOG-ZY125-06)the Knowledge Innovation Project,Chinese Academic Sciences(KZCX2-YW-136-1)
文摘Platinum-group elements (PGE) in PGE-rich porphyry copper (gold) deposits are mainly Pt and Pd, whereas the concentrations of other PGE (Ru, Rh, Os, Ir) are significantly low. Moreover, Pt and Pd mainly exist in sulfides in the forms of crystal lattice or tiny platinum-group mineral (PGM) inclusions. The present data show that there is a positive relationship between Pt and Pd concentrations and Cu (Au) in porphyry copper (gold) deposits. The comparison of chondrite-normalized PGE distribution patterns between the ore-bearing porphyry intrusions and ore-barren porphyry intrusions in arc setting, 187^Os/188^Os, 87^Sr/86^Sr and S isotopes for porphyry copper (gold) deposits shows that PGEs were mainly derived from the mantle, and fluids from subduction zones devoted trivial PGE to the magma. The porphyry copper (gold) deposits associated with subducted events are most probably enriched in PGE, whereas those related to crustal thickening, lithospheric delamination or underplating rarely concentrate PGE. The osmium isotopic compositions in porphyry copper (gold) deposits reveal that (187^Os/188^Os)i values are highly variable and not lower than those of primitive upper mantle (PUM) and mantle peridotite, however, osmium concentrations are commonly lower than mantle peridotite, suggesting that parental magmas of some porphyry intrusions had experienced crustal contamination during magma evolution. Experimental investigations have proved that PGE exist in the forms of Cl^- and HS^- complexes during transportation and migration of the oreforming fluids. This paper summarizes previous studies including crucial controlling factors and mechanisms for PGE enrichment, and points out that the mantle-derived magmas parental to porphyry intrusions are the prerequisite for PGE enrichment in porphyry copper (gold) deposits. Favorable physical and chemical conditions (including salinity, temperature, pressure, pH, and oxygen fugacity) in hydrothermal fluids crucially control the PGE enrichment, and sulfur concentrations of melts play important roles in this process as well.
文摘The middle south parts of Tancheng Lujiang deep fault zone and its vicinity are an important locality of Cu Au deposits related to Mesozoic volcanic subvolcanic magmatism in eastern China. According to their metallogenic features and ore forming conditions, copper gold deposits in this district are ascribed to two groups: the epithermal group which can be further divided into tellurium gold type, quartz adularia type and quartz manganoansiderite type; the magmatic hydrothermal group which includes porphyry Cu Au deposit, breccia pipe porphyry type Au Cu deposit and skarn type Au Cu deposit. In this paper, characteristics of six typical shoshonite hosted Cu Au deposits are outlined. Additionally, the factors that control the metallogenesis and distribution of these Cu Au deposits are discussed preliminarily.
文摘The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural trap. The mechanism has three major features: (1) timing of mineralization; (2) positioning of hostformation; and (3) dependence of ore-controlling structure on properties of rocks. The 'optimum surface' is adivisional structural plane which marks obvious difference in physical, chemical and mechanical properties andis favorable for mineralization. It is also a unity of structures. lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the ma-jor characteristic clements in the ore-controlling fault belt: elements with a small radius (Si, Fe, Mg and Al)moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remotefrom the center.
基金supported by the National Key Research and Development Program of China (2022YFC2905001)the National Natural Science Foundation of China (42272093,42230813)+1 种基金China Scholarship Council projectthe Geological Survey project (DD20230054)
文摘Jiama,with more than 11 Mt of copper metal,is the largest porphyry-skarn copper system in the Gangdese metallogenic belt,Tibet,China,creating ideal conditions for deciphering the origin of porphyry ores in a collision setting.Despite massive studies of the geology,chronology,petrogenesis,and ore-related fluids and their sources in Jiama,there is a lack of systematic summaries and reviews of this system.In contrast to traditional porphyry copper systems in a subduction setting,recent studies and exploration suggest that the Jiama deposit includes porphyry-type Mo-Cu,skarn-type Cu polymetallic,vein-type Au and manto orebodies.This paper reviews the latest studies on the geology,chronology,petrogenesis,fluid inclusions,and isotopic geochemistry(hydrogen,oxygen,sulfur,and lead)of the Jiama deposit.Accordingly,a multi-center complex mineralization model was constructed,indicating that multi-phase intrusions from the same magma reservoir can form multiple hydrothermal centers.These centers are mutually independent and form various orebodies or are superimposed on each other and form thick,high-grade orebodies.Finally,a new comprehensive exploration model was established for the Jiama porphyry copper system.Both models established in this study help to refine the theories on continental-collision metallogeny and porphyry copper systems.
基金supported by the National Key Research and Development Program of China(2018YFC0604102)the project of China Geological Survey(DD20190015)。
文摘The Jiama porphyry copper deposit in Tibet is one of the proven supergiant copper deposits in the Qinghai-Tibet Plateau at present,with the reserves of geological resources equivalent to nearly 20×10^(6) t.However,it features wavy and steep terrain,leading to extremely difficult field operation and heavy interference.This study attempts to determine the effects of the tensor controlled-source audiomagnetotellurics(CSAMT)with high-power orthogonal signal sources(also referred to as the high-power tensor CSAMT)when it is applied to the deep geophysical exploration in plateaus with complex terrain and mining areas with strong interference.The test results show that the high current provided by the highpower tensor CSAMT not only greatly improved the signal-to-noise ratio but also guaranteed that effective signals were received in the case of a long transmitter-receiver distance.Meanwhile,the tensor data better described the anisotropy of deep geologic bodies.In addition,the tests also show that when the transmitting current reaches 60 A,it is still guaranteed that strong enough signals can be received in the case of the transmitter-receiver distance of about 25 km,sounding curves show no near field effect,and effective exploration depth can reach 3 km.The 2D inversion results are roughly consistent with drilling results,indicating that the high-power tensor CSAMT can be used to achieve nearly actual characteristics of underground electrical structures.Therefore,this method has great potential for application in deep geophysical exploration in plateaus and mining areas with complex terrain and strong interference,respectively.This study not only serves as important guidance on the prospecting in the Qinghai-Tibet Plateau but also can be used as positive references for deep mineral exploration in other areas.
文摘The Lut block, eastern Iran, is one of the most extensive Cenozoic magmatic rocks, that show suitable targets for porphyry Cu-Au and high-sulfidation epithermal Au related to porphyry Cu-Au mineralization. In this study, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was used to identify different erosion levels of three porphyry Cu deposits, including Maherabad, Shadan, and Chah Shaljami, located in the Lut block volcanic-plutonic belt. Alteration minerals, including kaolinite, dickite, alunite, jarosite, epidote, chlorite, montmorillonite, muscovite, biotite, orthoclase, gypsum, and quartz, are selected to map different alteration zones and erosion levels. Distributions of end-members are mapped by using the SAM and MTMF in VNIR and SWIR of ASTER bands and the results are evaluated against the field studies. For some end-members, the results of SAM processing are more reliable compared to the MTMF because the latter looses field spectra. The use of angle threshold in the SAM, and MF-score and infeasibility value in the MTMF or low abundance of some end-members, and finally comparison of output images of spectral processing show good correlation with alteration maps. Differentiation and explanation of various erosion levels of porphyry Cu deposits are done successfully by using the ASTER sensor data.
文摘Tongguanshan copper deposit of Tongling large ore belt is one of the typicalskarn copper deposits. Based on careful observation under microscope many daughter mineralsincluding transparent ones and opaque ones have been distinguished in the fluid inclusions of garnetand diopside. The results of SEM/EDS (scanning electron microscope/energy dispersive spectrometer)and LRM (laser Raman microprobe) analysis show that these daughter minerals in garnet are sylvite,halite, sphalerite, chalcopyrite and carbonate. Sylvite daughter mineral is very popular in garnetand diopside. The existence of so much sylvite daughter mineral and other daughter minerals in thefluid inclusions indicates that the ore--forming fluid is of supper-high salinity and high potassiumconcentration. High potassium concentration in the fluid inclusions agrees with K-richmesotype--acid rock and K-silicate alteration that occurred widely in this area. The daughtermineral assemblage in garnet and diopside is similar to the mineral assemblage of ore-forming stagethat followed skarn stage.
文摘This paper describes three main parts of GIS technique used in prospecting of copper deposits. Firstly, this paper briefly introduces GIS technique for data preparation. Then it discusses the geo anomaly (GA) analysis and targets delineation methods, where the unit ore equivalent calculation of planar GA and the transformation and evaluation of linear GA are dominant. In addition, the method for copper prospecting is demonstrated. Finally a case study of copper deposit prospecting in Yuanjiang, Yunnan Province is presented by the use of MAPGIS.
基金financially supported by the Study on mineralization background and conditions of copper-gold in the western part of Bangongco-Nujiang metallogenic belt of Ministry of land and resources of Public industry research and special projects(201011013)Opening Foundation of Key Laboratory of Tectonic Controls on Mineralization and Hydrocarbon Accumulation,Ministry of Land and Resources(gzck2013006)Tectonic metallogeny theory development and practice team fund of Sichuan Province(13TD0008)
文摘The Naruo porphyry copper-gold deposit (hereinafter referred to as the Naruo deposit) in Tibet is a potentially ultra-large, typical gold-rich porphyry copper deposit, which was recently discovered in the Bangongco-Nujiang metallogenic belt. This study analyzed U-Ph chronology and Hf isotopes of the ore-bearing granodiorite porphyry in the Naruo deposit using the LA-ICPMS dating technique. The results show that the weighted average age is 124.03±0.94Ma (MSWD=1.7, n=20), and 2±6pb/23SU isocbron age is 126.2±2.7 Ma (MSWD=1.02, n=20), both of which are within the error. The weighted average age represents the crystallization age of the granodiorite porphyry, which indicates that the ore-bearing porphyry in the Naruo deposit area was formed in the Early Cretaceous and further implies that the Neo-tethys Ocean had not been closed before 124 Ma under a typical island-arc subduction environment. The εGr(t) of zircons from the granodiorite porphyry varies from 2.14 to 9.07, with an average of 5.18, and all zircons have εRf(t) values greater than 0; 176Hf/177Hf ratio is relatively high (0.282725-0.282986). Combined with the zircon age--Hf isotope correlation diagram, the aforementioned data indicate that the source reservoir might be a region that is mixed with depleted mantle and ancient crust, which possibly contains more materials sourced from depleted mantle. Rock-forming ages and ore-forming ages of the Duolong ore concentrate area are 120-124 Ma and 118-119 Ma, respectively, which indicate 124-118 Ma represents the main rockforming and ore-forming stage within the area. The Naruo deposit is located in the north of the Bangongco-Nujiang suture, and it yielded a zircon LA-ICPMS age of 124.03 Ma. This indicates the Bangongco-Nujiang oceanic basin subducted towards the north at about 124 Ma, and the Neo-tethys Ocean had not been closed before the middle Early Cretaceous. It is possible that the crust-mantle mixing formed the series of large and giant porphyry copper-gold deposits in the Bangongco.
基金financially supported by the Ministry of Land and Resources’ projects (No. 200911007-01 and No.201111020-05)China Geological Survey’s geology and mineral resources survey projects (No.1212011085408)
文摘The Dexing porphyry copper ore mine is located in the Qin-Hang metallogenic belt between the Yangtze block and the Cathaysia block. It is a giant porphyry copper mine in China, including 3 ore districts: Tongchang, Fujiawu and Zhushahong. Our analyses of Re in molybdenite indicate that the ore-forming material of the copper ore deposits in Dexing should be mainly mantle-derived. Our study fills in a gap in the study of formation time of the Dexing copper mine, and further proves that the copper ore deposits in the three ore districts should be formed simultaneously, about 170 Ma, belonging to the early Yanshan period, and that the formation time of the copper ore deposits should be consistent with the formation time of granodiorite porphyry in which the copper ore deposits are hosted. Promising areas for seeking porphyry copper ore deposits is predicated to be the west or southwest of Dexing.
文摘The Hongshan porphyry-cryptoexplosive breccia type copper deposit occurs in a metamorphic rock series of the Mesoproterozoic Zhongcun Group. Orebodies are distributed inside and outside porphyry-cryptoexplosive breccia pipes. The deposit involves five ore-forming types, i.e the porphyry type, cryptoexplosive breccia type, contact-zone veinlet-disseminated type, in-pipe fracture-zone filling-replacement type and out-of-pipe fracture-zone filling-replacement type, forming an ore-forming system of “five ore-forming types within a single rock body”. Fluid inclusion and isotope geochemical studies indicate the following: S, Pb, O and Sr were derived from the lower crust, Nd was derived from the continental crust or depleted mantle and rare earth elements (REE) and trace elements have the crustal source characters; fluids consist dominantly of formation water, metamorphic water and ***meteoric water with a part of magmatic mater, heat came from porphyry while the latter originated from partial melting caused by shear heating in the lower crust and upper mantle. According to its origin the deposit is classified as the hypabyssal and near-surface, meso- and hypothermal copper deposit associated with the late Yanshanian porphyry-cryptoexplosive breccia.
文摘The geochemical features of REE were studied by comparing the copper ore with the skarn, the diorite and the stratum, to trace the source of metallogenic materials in Anqing copper deposit, Anhui. The origin of metallogenic hydrothermal fluids was studied through simulating REE pattern of the balanceable hydrothermal fluids. The results indicate that the metallogenic materials come from the diorite and the metallogenic hydrothermal fluids come from the dioritic magma. The results also show that the rare earth elements are relatively mobile during metallization.
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.