Rubidium(Rb)deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated granites.This study investigates a newly-discovered giant Rb deposit at ...Rubidium(Rb)deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated granites.This study investigates a newly-discovered giant Rb deposit at Gariatong in the Central Lhasa terrane in Tibet.Detailed field studies and logging data revealed that the Rb mineralization mainly occurs in monzogranite and is related to greisenization.LA-ICP-MS U-Pb dating of zircon yielded ages of 19.1±0.2 Ma and 19.0±0.2 Ma for greisenized monzogranite and fresh monzogranite,respectively.The monzogranites are characterized as strongly peraluminous,with high contents of SiO2,Al2O3,K2O and Na2O as well as a high differentiation index.They are enriched in light rare earth and large ion lithophile elements with significant negative Eu anomalies and depleted high fieldstrength elements.Petrological and geochemical features of these ore-related monzogranites suggest that they are highly fractionated S-type granites,derived from remelting of crustal materials in a post-collisional setting.The geochemistry of zircon and apatite points to a low oxygen fugacity of the ore-related monzogranite during the magma’s evolution.The discovery of the Gariatong Rb deposit suggests that the Central Lhasa terrane may be an important region for rare metal mineralization.展开更多
The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for stu...The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for studies using petrographic, geochemical and metallogenic methods. The study of macroscopic and microscopic petrography made it possible to highlight two major lithological units: 1) a volcano-plutonic unit, formed of gabbros, basalt, volcaniclastics and rhyodacite;2) a sedimentary unit (microconglomerate). From a geochemical point of view, the results obtained indicate that the plutonites are gabbro and gabbro diorite while the volcanics have compositions of basaltic andesites, rhyolite and dacites. The sediments have a litharenitic to sublitharenitic character. The metallogenic study made it possible to highlight hydrothermal alterations and metalliferous paragenesis on the formations studied. Hydrothermal alteration is characterized by the presence of carbonation, silicification, sericitization, sulfidation and to a lesser degree chloritization. Metalliferous paragenesis consists of pyrite, chalcopyrite, hematite and magnetite.展开更多
Tectonic processes involving amalgamations of microblocks along zones of ocean closure represented by granite-greenstone belts(GGB) were fundamental in building the Earth's early continents. The crustal growth and...Tectonic processes involving amalgamations of microblocks along zones of ocean closure represented by granite-greenstone belts(GGB) were fundamental in building the Earth's early continents. The crustal growth and cratonization of the North China Craton(NCC) are correlated to the amalgamation of microblocks welded by 2.75-2.6 Ga and ~2.5 Ga GGBs. The lithological assemblages in the GGBs are broadly represented by volcano-sedimentary sequences, subduction-collision related granitoids and bimodal volcanic rocks(basalt and dacite) interlayered with minor komatiites and calc-alkalic volcanic rocks(basalt, andesite and felsic rock). The geochemical features of meta-basalts in the major GGBs of the NCC display affinity with N-MORB, E-MORB, OIB and calc-alkaline basalt, suggesting that the microblocks were separated by oceanic realm. The granitoid rocks display arc signature with enrichment of LILE(K,Rb, Sr, Ba) and LREE, and depletion of HFSE(Nb, Ta, Th, U, Ti) and HREE, and fall in the VAG field. The major mineralization includes Neoarchean BIF-type iron and VMS-type Cu-Zb deposits and these,together with the associated supracrustal rocks possibly formed in back-arc basins or arc-related oceanic slab subduction setting with or without input from mantle plumes. The 2.75-2.60 Ga TTG rocks,komatiites, meta-basalts and metasedimentary rocks in the Yanlingguan GGB are correlated to the upwelling mantle plume with eruption close to the continental margin within an ocean basin. The volcanosedimentary rocks and granitoid rocks in the late Neoarchean GGBs display formation ages of 2.60-2.48 Ga, followed by metamorphism at 2.52-2.47 Ga, corresponding to a typical modern-style subduction-collision system operating at the dawn of Proterozoic. The late Neoarchean komatiite(Dongwufenzi GGB), sanukitoid(Dongwufenzi GGB and Western Shandong GGB), BIF(Zunhua GGB) and VMS deposit(Hongtoushan-Qingyuan-Helong GGB) have closer connection to a combined process of oceanic slab subduction and mantle plume. The Neoarchean cratonization of the NCC appears to have involved two stages of tectonic process along the 2.75-2.6 Ga GGB and ~2.5 Ga GGBs, the former involve plume-arc interaction process, and the latter involving oceanic lithospheric subduction, with or without arcplume interaction.展开更多
The North China Craton(NCC)hosts some of the world-class gold deposits that formed more than 2 billion years after the major orogenic cycles and cratonization.The diverse models for the genesis of these deposits remai...The North China Craton(NCC)hosts some of the world-class gold deposits that formed more than 2 billion years after the major orogenic cycles and cratonization.The diverse models for the genesis of these deposits remain equivocal,and mostly focused on the craton margin examples,although synchronous deposits formed in the interior domains.Here we adopt an integrated geological and geophysical perspective to evaluate the possible factors that contributed to the formation of the major gold deposits in the NCC.In the Archean tectonic framework of the NCC,the locations of the major gold deposits fall within or adjacent to greenstone belts or the margins of micro-continents.In the Paleoproterozoic framework,they are markedly aligned along two major collisional sutures-the Trans North China Orogen and the Jiao-Liao-Ji Belt.Since the Mesozoic intrusions hosting these deposits do not carry adequate signals for the source of gold,we explore the deep roots based on available geophysical data.We show that the gold deposits are preferentially distributed above zones of uplifted MOHO and shallow LAB corresponding to thinned crust and eroded sub-lithospheric mantle,and that the mineralization is located above regions of high heat flow representing mantle upwelling.The NCC was at the center of a multi-convergent regime during the Mesozoic which intensely churned the mantle and significantly en riched it.The geophysical data on Moho and LAB upwarp from the centre towards east of the craton is more consistent with paleo-Pacific slab subduction from the east exerting the dominant control on lithospheric thinning.Based on these results,and together with an evaluation of the geochemical and isotopic features of the Mesozoic magmatic intrusions hosting the gold mineralization,we propose a genetic model that invokes reworking of ancient Au archives preserved in the lower crust and metasomatised upper mantle and which were generated through multiple subduction,underplating and cumulation events associated with cratonization of the NCC as well as the subduction-collision of Yangtze Craton with the NCC.The heat and material input along zones of heterogeneously thinned lithosphere from a rising turbulent mantle triggered by Mesozoic convergent margins surrounding the craton aided in reworking the deep roots of the ancient Au reservoirs,leading to the major gold metallogeny along craton margins as well as in the interior of the NCC.展开更多
South China is endowed with copious wolframite-quartz vein-type W deposits that provide a significant contribution to the world‘s tungsten production.Mineralization is spatially associated with highly evolved granite...South China is endowed with copious wolframite-quartz vein-type W deposits that provide a significant contribution to the world‘s tungsten production.Mineralization is spatially associated with highly evolved granites,which have been interpreted as products of ancient crustal anatexis.Ore veins are mainly hosted in low-grade metamorphosed quartz sandstone,slate and granitic rocks.The ore minerals mainly comprise wolframite,cassiterite,scheelite and pyrite,with minor molybdenite,arsenopyrite and chalcopyrite.Typical steeply dipping veins can be divided into five zones from top to the bottom,namely:(Ⅰ)thread,(Ⅱ)veinlet,(Ⅲ)moderate vein,(Ⅳ)thick vein,and(Ⅴ)thin out zones.In general,three types of fluid inclusions at room temperature are commonly recognized in wolframite and/or quartz from these veins:two-phase liquid-rich(type L),two-phase CO2-bearing(type CB),and CO2-rich(type C).Comparative microthermometry performed on fluid inclusions hosted in wolframite and associated quartz indicates that most wolframite was not coprecipitated with the coexisting quartz.Detailed petrographic observation and cathodoluminescence(CL)imaging on coexisting wolframite and quartz of the Yaogangxian deposit,show repeated precipitation of quartz,wolframite,and muscovite,suggesting a more complex fluid process forming these veins.Previous studies of H-O isotopes and fluid inclusions suggested that the main ore-forming fluids forming the wolframite-quartz vein-type deposits had a magmatic source,whereas an unresolved debate is centered on whether mantle material supplemented the ore-forming fluids.The variable CO2 contents in the ore-forming fluids also implies that CO2 might have had a positive effect on ore formation.Fluid inclusion studies indicate that wolframite was most likely deposited during cooling from an initial H2 O+Na Cl±CO2 magmatic fluid.In addition,fluid-phase separation and/or mixing with sedimentary fluid might also have played an important role in promoting wolframite deposition.We speculate that these processes determine the precipitation of W to varying degrees whereas the leading mechanistic cause remains an open question.Comprehensive studies on spatial variation of fluid inclusions show that both the steeply and gently dipping veins are consistent with the"five floors"model that may have broader applications to exploration of wolframite-quartz vein-type deposits.Recent quantitative analysis of wolframite-and quartz-hosted fluid inclusions by laser ablation inductively-coupled plasma mass spectrometry shows enhanced advantages in revealing fluid evolution,tracing the fluid source and dissecting the ore precipitation process.Further studies on wolframite-quartz vein-type W deposits to bring a deeper understanding on ore-forming fluids and the metallogenic mechanism involved.展开更多
The research on Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region of Central Asia is an important and significant project. The Altay region, as a collision zone of the Early Paleozoic (500-39...The research on Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region of Central Asia is an important and significant project. The Altay region, as a collision zone of the Early Paleozoic (500-397 Ma), and the Tianshan region, as a collision zone of the early period in the Late Paleozoic (Late Devonian-Early Carboniferous, 385-323 Ma), are all the result of nearly N-S trending shortening and collision (according to recent magnetic orientation). In the Late Devonian-Early Carboniferous period (385-323 Ma), regional NW trending faults displayed features of dextral strike-slip motion in the Altay and Junggar regions. In the Tianshan region, nearly EW-trending regional faults are motions of the thrusts. However, in the Late Carboniferous-Early Permian period (323-260 Ma), influenced by the long-distance effect induced from the Ural collision zone, those areas suffered weaker eastward compression, the existing NW trending faults converted into sinistral strike-slip in the Altay and Junggar regions, and the existing nearly E-W trending faults transferred into dextral strike-slip faults in the Tianshan region. The Rocks of those regions in the Late Carboniferous-Early Permian period (323-260 Ma) were moderately ruptured to a certain tension-shear, and thus formed a number of world famous giant endogenic metal ore deposits in the Tianshan-Altay region. As to the Central Asian continent, the most powerful collision period may not coincide with the most favorable endogenic metallogenic period. It should be treated to "the orogenic metallogeny hypothesis" with caution in that region.展开更多
This paper is briefly involved in distributions of China's uranium metallogenic types, provinces, regions and belts. Eight target regions have been pointed out to be worthy of prospecting for uranium resources. The r...This paper is briefly involved in distributions of China's uranium metallogenic types, provinces, regions and belts. Eight target regions have been pointed out to be worthy of prospecting for uranium resources. The regional uranium metallogeny is discussed and great uranium potential pointed out from many aspects. Generally speaking, there are favorable conditions for uranium mineralization and good perspective to explore for uranium resources.展开更多
The west sector of the northern Qilian Mountains is well-known for the Jingtieshan-type iron deposits. A new breakthrough has been made in prospecting for gold and copper in recent years. In this paper, the distributi...The west sector of the northern Qilian Mountains is well-known for the Jingtieshan-type iron deposits. A new breakthrough has been made in prospecting for gold and copper in recent years. In this paper, the distribution characteristics of ore deposits in the study area are discussed from the viewpoint of tectonic evolution. It is suggested that there are 9 stages of mineralization from the Palaeoproterozoic to Indosinian. Four minerogenetic series and two minerogenetic subseries of ore deposits are recognized. Iron mineralization occurred in several stages, while most of the metals were accumulated in large amounts in the Caledonian. The enrichment and mineralization of gold is related to large-scale shear-strike-slip faults and the ascent and unloading of deep-seated fluids.展开更多
Continental reconstructions in Central Asia are represented by orogenesis along some large orogenic belts in the Altaid collage (Fig. 1 ) or Central Asian Orogenic Belt (CAOB), which separate the East European and...Continental reconstructions in Central Asia are represented by orogenesis along some large orogenic belts in the Altaid collage (Fig. 1 ) or Central Asian Orogenic Belt (CAOB), which separate the East European and Siberian cratons to the north from the Tarim and North China cratons to the south ($eng0r et al,, 1993; Jahn et al., 2004; Windley et al., 2007; Qu et al., 2008; Xiao et al., 2010; Xiao and Santosh, 2014). The Altaid Collage was characterized by complex long tectonic and structural evolution from at least ca. 1.0 Ga to late Paleozoic-early Mesozoic with considerable continental growth (Khain et al., 2002; Jahn et al., 2004; Xiao et al., 2009, 2014; KrOner et al., 2014), followed by Cenozoic intracontinental evolution related to far-field effect of the collision of the In- dian Plate to the Eurasian Accompanying with these complex world-class ore deposits developed 2001; Goldfarb et al., 2003, 2014). Plate (Cunningham, 2005). geodynamic evolutions, many (Qin, 2000; Yakubchuk et al,2001; Goldfarb et al., 2003, 2014).展开更多
The Lannigou deposit is a large-sized sedimentary rock-hosted disseminated gold (SRHDG) deposit located in the Youjiang Basin. It is hosted by the Middle Triassic turbidite. Wall rock alterations, including silicifi...The Lannigou deposit is a large-sized sedimentary rock-hosted disseminated gold (SRHDG) deposit located in the Youjiang Basin. It is hosted by the Middle Triassic turbidite. Wall rock alterations, including silicification, pyritization, arsenopyritization, carbonatization and argillization, commonly occur along fractures. PGE study demonstrates that either Permian basalts or Triassic ultrabasic intrnsives are unlikely to be the main source of gold mineralization. Coupled with the lack of other nmgmatic activity in the vicinity of the mining area, an amagmatic origin is proposed. Organic matter compositions and GC-MS analysis of the ores and host rocks show that the organics in the ores and the host rocks have a common source; the organic matter in the ores was mainly indigenous. The positive correlation between S2 and Au contents, along with the common occurrence of organic inclusions, suggest involvement of organic matter in the ore-forming process in terms of promoting Au leaching from the source rocks, making colloidal Au migration possible, as well as hydrocarbon reduction of sulphate. Geological and geochemical characteristics of the Lannigou deposit suggest that it was formed through circulation of meteoric water and probably less importantly organic bearing formation water driven by high geothermal gradient caused by late Yanshanian extension, which leached Au from the source bed, and then migrated as Au-bisnlfides and colloidal Au, culminating in deposition by reduction-adsorption and surface complexation of gold onto the growth surface of arsenlan pyrite.展开更多
A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongli...A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongling, Anhui Province. The major reasons for the formation of the stratabound skarn Au-S ore deposit in Tianmashan and the stratabound skarn Cu ore deposit in Datuanshan are analyzed in accordance with this contrast. The magmatic pluton in Tianmashan is rich in Au and poor in Cu, but that in Datuanshan is rich in Cu and Au. The wallrock strata in Tianmashan contain Au-bearing pyrite layers with some organic substance but those in Datuanshan contain no such layers. Moreover, the ore-forming fluids in Tianmashan are dominantly magmatic ones at the oxide and sulfide stages, but those with high content of Cu in Datuanshan are mainly groundwater fluids. In addition, differences in compositional evolution and physicochemical condition variation of the ore-forming fluids result in gradual dispersion展开更多
The Berezitovoe deposit in the Sergachi volcano-plutonic and metallogenic belt preserves evidence for polymetallic mineralization of multiple stages.The steeply dipping gamet-tourmaline-muscovite-quartz metasomatites...The Berezitovoe deposit in the Sergachi volcano-plutonic and metallogenic belt preserves evidence for polymetallic mineralization of multiple stages.The steeply dipping gamet-tourmaline-muscovite-quartz metasomatites(with K-Ar ages of 132 ± 2.9 and 127 ± 4.4 Ma) carry two distinct stages of mineralization developed at different times:(1) polymetallic mineralization and(2) gold-quartz.The deposit is located within Paleozoic gneissose granitoids of the Pikansky complex(dated as 379 ± 1.1 Ma by zircon U-Pb method) intruded by early Cretaceous porphyry-like granites of the Haikta pluton(dated as137 ± 0.67 Ma by zircon U-Pb method) and late Cretaceous dikes of porphyrites,porphyries,and lamprophyres.Evidence suggests the action of late gold-bearing hydrothermal fluids on the early polymetallic ores and the selective mobilization of some elements from these lead to redeposition together with complex sulphosalts.展开更多
The Taishanmiao Au deposit is in the western part of the Ningshan-Zhenan ore field,in the South Qinling orogen.Based on geological and geochemical features,we propose that the Taishanmiao Au deposit is a magmatichydro...The Taishanmiao Au deposit is in the western part of the Ningshan-Zhenan ore field,in the South Qinling orogen.Based on geological and geochemical features,we propose that the Taishanmiao Au deposit is a magmatichydrothermal type of deposit.All samples have high SiO_(2),K_(2)O+Na_(2)O contents and differentiation index values,low CaO,MgO,P_(2)O_(5),and TiO_(2)contents,are enriched in high field-strength elements,and depleted in large ion lithophile element.The stable isotopeδ^(34)S values of pyrite vary from 6.8%-7.8%,and the H-O isotopic compositions of quartz from quartzpyrite veins indicate the ore-forming fluid is a mixture of a small amount of magmatic-hydrothermal solution and groundwater.Lead isotope ratios of pyrite and silicalite can show that the ore-forming materials were derived from a mixed source containing mantle and crustal materials.At the same time,the LA-ICP-MS U-Pb dating of monzogranite is 198.4±4.2 Ma.Combined with the regional geological background,the intracontinental extension in the late collisional orogeny and large-scale lithospheric thinning associated with mantle uplift may lead to large-scale mineralisation in the region.展开更多
This paper proposes a new tectonic pattern of the deep-seated structures in China and its adjacent areas (including the T - A - B system of the Ryukyu Islands). This is based on studies of the gravity field and gravit...This paper proposes a new tectonic pattern of the deep-seated structures in China and its adjacent areas (including the T - A - B system of the Ryukyu Islands). This is based on studies of the gravity field and gravity inversion coupled with the summation of the most recent achievements in geophysical studies. From a plate-tectonic point of view, the metallogenic characteristics and their indications at depth, as well as relevant geophysical-geological characteristics of four tectonic environments of the Chinese continent are analysed, and a classification of composite metallogenic provinces and belts and prediction of metallogenic prospects are made. The author extends the Kunlun-Qilian-Qinling tectonic belt to the T-A-B system of the Ryukyu Islands through the NW deep boundary of the Hangzhou Bay, and also proposes the following basic views' the migration and superposition of tectonic environments led to the formation of a composite metallogenic system; the change in the tectonic environment resulted in the superposition of various types of mineral deposits; seismic activities and metallogeny are mutually inducing factors. These views will be helpful to a discussion on the tectonic environments and metallogenic regularities.展开更多
The Hongdonggou Pb-Zn polymetallic ore deposit, located in the southwestern part of the Luanchuan Mo-W-Pb-Zn-Ag polymetallic ore mineralization in Henan Province, China, is an important part of the East Qinling metall...The Hongdonggou Pb-Zn polymetallic ore deposit, located in the southwestern part of the Luanchuan Mo-W-Pb-Zn-Ag polymetallic ore mineralization in Henan Province, China, is an important part of the East Qinling metallogenic belt. The orebodies in the deposit, which are vein, bedded and lenticular, are mainly hosted in the syenite porphyry, and formed within the carbonate and clastic rocks of the Yuku and Qiumugou formations partially. The genesis of the deposit has previously been argued to be of hydrothermal-vein type or of skarn-hydrothermal type. In this study, we report the results of Rb-Sr isotopic dating based on sphalerites from the main orebody of the Hongdonggou Pb-Zn polymetallic ore deposit, which yield an isochron age of 135.7 ± 3.2 Ma, constraining the timing of mineralization as early Cretaceous. The age is close to those reported for the Pb-Zn deposits in the Luanchuan ore belt. The (87Sr/86Sr)i values of the sphalerites (0.71127± 0.00010) are lower than that of terrigenous silicates (0.720) and higher than the mantle (0.707), suggesting that the metallogenic components were mainly derived through crust-mantle mixing. Combining the results from this study with those from previous work, we propose that the Hongdonggou Pb-Zn polymetallic ore deposit is a hydrothermal-vein deposit associated with the early Cretaceous tectonothermal event, and the mineralization is controlled by NW- and near EW-trending faults in the Luanchuan Mo-W-Pb-Zn-Ag polymetallic ore concentration belt.展开更多
The geodynamic development of Eurasian active margin is related to subduction,collision and closure of Tethys Ocean.It is divided on pre-collision and post-collision stages.The pre-collision development controlled by ...The geodynamic development of Eurasian active margin is related to subduction,collision and closure of Tethys Ocean.It is divided on pre-collision and post-collision stages.The pre-collision development controlled by subduction,whereas post-collision related by orogenesis,granodiorite magmatism gold base and trace metals(Sb,W,Mo and Hg)metallogeny.The mentioned trace metals association is the geochemical indicator of first stage of post-collision development.The second stage revealed in andesite basalt,shoshonite,olivine basalt and tholeiite volcanic activity.Pre-collision stage is controlled by steady state subduction related with metamorphism and calc-alkaline volcanic activity in subaqual and island conditions of island arc setting.It is lately with steepening of subducting slab and incursion of mantle diapir transferred in interarc-backarc and minor ocean setting with shoshonite-trachyandesite and alkali olivine basalt and tholeiite volcanism and later with ophiolite volcanism,dunite-peridotite magmatism and Cu-pyrite mineralization of minor ocean setting.The pre-collision stage is developed temporally and spacially along dipping of subducted slab in the island arc setting transferring in the backarc-interarc and minor ocean settings.The similar transferring occurs laterally to dipping of slab and ascending succession.The alternation of settings shown the cycling along dipping spatial and temporal alternation of island arc,backarc and minor ocean settings.Laterally to dipping alternation is only spatial,whereas in ascending succession cycling is only temporal,localized spacially.The pre-collision development occurs in subaqual condition,whereas related to orogenesis post-collision development is mainly subaerial.展开更多
The correlation between the North China Craton(NCC) and the Indian Shield(IND) has been a hot topic in recent years,On the basis of ore deposit databases,the NCC and IND have shown broad similarity in metallogenes...The correlation between the North China Craton(NCC) and the Indian Shield(IND) has been a hot topic in recent years,On the basis of ore deposit databases,the NCC and IND have shown broad similarity in metallogenesis from the middle Archaean to the Mesoproterozoic,The two blocks both have three major metallogenic systems:(1) the Archaean BIF metallogenic system;(2) the Paleoproterozoic Cu-Pb-Zn metallogenic system;and(3) the Mesoproterozoic Fe-Pb-Zn system,In the north margin of the NCC and the west margin of the IND,the Archaean BIF-Au-Cu-Pb-Zn deposits had the same petrogenesis and host rocks,the Paleoproterozoic Cu-Pb-Zn deposits were controlled by active belts,and the Mesoproterozoic Fe-Pb-Zn deposits were mainly related to multi-stage rifting,Matching regional mineralization patterns and geological features has established the continental assembly referred to as "NCWI",an acronym for the north margin of the NCC(NC) and the west margin of the IND(WI) during the middle Archaean to the Mesoproterozoic,In this assembly,the available geological and metallogenic data from the Eastern Block and active belts of NC fit those from the Dharwar craton and the Aravalli-DelhiVindhyan belt of WI,respectively,Moreover,the depositional model and environment of Paleoproterozoic metasedimentary manganese deposits in NCWI implied that the assembly may be located at low latitudes,where the conditions were favorable for dissolving ice and precipitating manganese deposits,展开更多
The Gangdise plutonic\|volcanic arc is situated in the eastern section of the Tethys\|Himalaya metallogenic province. It is acknowledged as a “tectonic\|magmatic complex" because of its well\|developed fault and...The Gangdise plutonic\|volcanic arc is situated in the eastern section of the Tethys\|Himalaya metallogenic province. It is acknowledged as a “tectonic\|magmatic complex" because of its well\|developed fault and igneous activities. Intermediate to acid plutons and dikes were mainly emplaced in the Upper Cretaceous to Lower Eocene volcanic rocks. The unique tectonic position and extremely complicated evolution history of the Gangdise arc have given rise to favorable conditions for polymetal mineralization. From Xietongmen in the west to Mozhugongka in the east of the arc, Au, Cu, Pb, Zn, and Ag show large ore\|forming potentials with well overlapped and highly intensified polymetal anomalies. In the arc region, many localities, like Jiama (Cu, Pb, Zn, Au, Ag) and Qulong (Cu, Pb, Zn) in Mozhugongka county, Lakang’e (Cu, Pb, Zn, Mo) in Lazi county, Tinggong (Cu, Mo) and Chongjiang (Cu, Mo) in Nimu county, Dabu (Cu, Au) in Qushui county, and Dongga (Au, Cu) in Xietongmen county, have sound prospective for polymetals.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC2905001)the National Natural Science Foundation of China(Grant Nos.42272093,42230813)+1 种基金the Basic Research Fund of the Chinese Academy of Geological Sciences(Grant Nos.JKYZD202316,KK2116)the China Scholarship Council project and the Geological Survey project(Grant No.DD20230054).
文摘Rubidium(Rb)deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated granites.This study investigates a newly-discovered giant Rb deposit at Gariatong in the Central Lhasa terrane in Tibet.Detailed field studies and logging data revealed that the Rb mineralization mainly occurs in monzogranite and is related to greisenization.LA-ICP-MS U-Pb dating of zircon yielded ages of 19.1±0.2 Ma and 19.0±0.2 Ma for greisenized monzogranite and fresh monzogranite,respectively.The monzogranites are characterized as strongly peraluminous,with high contents of SiO2,Al2O3,K2O and Na2O as well as a high differentiation index.They are enriched in light rare earth and large ion lithophile elements with significant negative Eu anomalies and depleted high fieldstrength elements.Petrological and geochemical features of these ore-related monzogranites suggest that they are highly fractionated S-type granites,derived from remelting of crustal materials in a post-collisional setting.The geochemistry of zircon and apatite points to a low oxygen fugacity of the ore-related monzogranite during the magma’s evolution.The discovery of the Gariatong Rb deposit suggests that the Central Lhasa terrane may be an important region for rare metal mineralization.
文摘The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for studies using petrographic, geochemical and metallogenic methods. The study of macroscopic and microscopic petrography made it possible to highlight two major lithological units: 1) a volcano-plutonic unit, formed of gabbros, basalt, volcaniclastics and rhyodacite;2) a sedimentary unit (microconglomerate). From a geochemical point of view, the results obtained indicate that the plutonites are gabbro and gabbro diorite while the volcanics have compositions of basaltic andesites, rhyolite and dacites. The sediments have a litharenitic to sublitharenitic character. The metallogenic study made it possible to highlight hydrothermal alterations and metalliferous paragenesis on the formations studied. Hydrothermal alteration is characterized by the presence of carbonation, silicification, sericitization, sulfidation and to a lesser degree chloritization. Metalliferous paragenesis consists of pyrite, chalcopyrite, hematite and magnetite.
基金jointly supported through the Foreign Expert grant from China University of Geosciences(Beijing)the Professorial position at the University of Adelaide, Australia to M.Santosh
文摘Tectonic processes involving amalgamations of microblocks along zones of ocean closure represented by granite-greenstone belts(GGB) were fundamental in building the Earth's early continents. The crustal growth and cratonization of the North China Craton(NCC) are correlated to the amalgamation of microblocks welded by 2.75-2.6 Ga and ~2.5 Ga GGBs. The lithological assemblages in the GGBs are broadly represented by volcano-sedimentary sequences, subduction-collision related granitoids and bimodal volcanic rocks(basalt and dacite) interlayered with minor komatiites and calc-alkalic volcanic rocks(basalt, andesite and felsic rock). The geochemical features of meta-basalts in the major GGBs of the NCC display affinity with N-MORB, E-MORB, OIB and calc-alkaline basalt, suggesting that the microblocks were separated by oceanic realm. The granitoid rocks display arc signature with enrichment of LILE(K,Rb, Sr, Ba) and LREE, and depletion of HFSE(Nb, Ta, Th, U, Ti) and HREE, and fall in the VAG field. The major mineralization includes Neoarchean BIF-type iron and VMS-type Cu-Zb deposits and these,together with the associated supracrustal rocks possibly formed in back-arc basins or arc-related oceanic slab subduction setting with or without input from mantle plumes. The 2.75-2.60 Ga TTG rocks,komatiites, meta-basalts and metasedimentary rocks in the Yanlingguan GGB are correlated to the upwelling mantle plume with eruption close to the continental margin within an ocean basin. The volcanosedimentary rocks and granitoid rocks in the late Neoarchean GGBs display formation ages of 2.60-2.48 Ga, followed by metamorphism at 2.52-2.47 Ga, corresponding to a typical modern-style subduction-collision system operating at the dawn of Proterozoic. The late Neoarchean komatiite(Dongwufenzi GGB), sanukitoid(Dongwufenzi GGB and Western Shandong GGB), BIF(Zunhua GGB) and VMS deposit(Hongtoushan-Qingyuan-Helong GGB) have closer connection to a combined process of oceanic slab subduction and mantle plume. The Neoarchean cratonization of the NCC appears to have involved two stages of tectonic process along the 2.75-2.6 Ga GGB and ~2.5 Ga GGBs, the former involve plume-arc interaction process, and the latter involving oceanic lithospheric subduction, with or without arcplume interaction.
基金funded by Fundamental Research Funds for the Central Universities (Grant No.2652018048)
文摘The North China Craton(NCC)hosts some of the world-class gold deposits that formed more than 2 billion years after the major orogenic cycles and cratonization.The diverse models for the genesis of these deposits remain equivocal,and mostly focused on the craton margin examples,although synchronous deposits formed in the interior domains.Here we adopt an integrated geological and geophysical perspective to evaluate the possible factors that contributed to the formation of the major gold deposits in the NCC.In the Archean tectonic framework of the NCC,the locations of the major gold deposits fall within or adjacent to greenstone belts or the margins of micro-continents.In the Paleoproterozoic framework,they are markedly aligned along two major collisional sutures-the Trans North China Orogen and the Jiao-Liao-Ji Belt.Since the Mesozoic intrusions hosting these deposits do not carry adequate signals for the source of gold,we explore the deep roots based on available geophysical data.We show that the gold deposits are preferentially distributed above zones of uplifted MOHO and shallow LAB corresponding to thinned crust and eroded sub-lithospheric mantle,and that the mineralization is located above regions of high heat flow representing mantle upwelling.The NCC was at the center of a multi-convergent regime during the Mesozoic which intensely churned the mantle and significantly en riched it.The geophysical data on Moho and LAB upwarp from the centre towards east of the craton is more consistent with paleo-Pacific slab subduction from the east exerting the dominant control on lithospheric thinning.Based on these results,and together with an evaluation of the geochemical and isotopic features of the Mesozoic magmatic intrusions hosting the gold mineralization,we propose a genetic model that invokes reworking of ancient Au archives preserved in the lower crust and metasomatised upper mantle and which were generated through multiple subduction,underplating and cumulation events associated with cratonization of the NCC as well as the subduction-collision of Yangtze Craton with the NCC.The heat and material input along zones of heterogeneously thinned lithosphere from a rising turbulent mantle triggered by Mesozoic convergent margins surrounding the craton aided in reworking the deep roots of the ancient Au reservoirs,leading to the major gold metallogeny along craton margins as well as in the interior of the NCC.
基金financially supported by a Key Project of the National Nature Science Foundation of China(Grant No.41830426)a National Key R&D Program of China Grant(No.2016YFC0600205)。
文摘South China is endowed with copious wolframite-quartz vein-type W deposits that provide a significant contribution to the world‘s tungsten production.Mineralization is spatially associated with highly evolved granites,which have been interpreted as products of ancient crustal anatexis.Ore veins are mainly hosted in low-grade metamorphosed quartz sandstone,slate and granitic rocks.The ore minerals mainly comprise wolframite,cassiterite,scheelite and pyrite,with minor molybdenite,arsenopyrite and chalcopyrite.Typical steeply dipping veins can be divided into five zones from top to the bottom,namely:(Ⅰ)thread,(Ⅱ)veinlet,(Ⅲ)moderate vein,(Ⅳ)thick vein,and(Ⅴ)thin out zones.In general,three types of fluid inclusions at room temperature are commonly recognized in wolframite and/or quartz from these veins:two-phase liquid-rich(type L),two-phase CO2-bearing(type CB),and CO2-rich(type C).Comparative microthermometry performed on fluid inclusions hosted in wolframite and associated quartz indicates that most wolframite was not coprecipitated with the coexisting quartz.Detailed petrographic observation and cathodoluminescence(CL)imaging on coexisting wolframite and quartz of the Yaogangxian deposit,show repeated precipitation of quartz,wolframite,and muscovite,suggesting a more complex fluid process forming these veins.Previous studies of H-O isotopes and fluid inclusions suggested that the main ore-forming fluids forming the wolframite-quartz vein-type deposits had a magmatic source,whereas an unresolved debate is centered on whether mantle material supplemented the ore-forming fluids.The variable CO2 contents in the ore-forming fluids also implies that CO2 might have had a positive effect on ore formation.Fluid inclusion studies indicate that wolframite was most likely deposited during cooling from an initial H2 O+Na Cl±CO2 magmatic fluid.In addition,fluid-phase separation and/or mixing with sedimentary fluid might also have played an important role in promoting wolframite deposition.We speculate that these processes determine the precipitation of W to varying degrees whereas the leading mechanistic cause remains an open question.Comprehensive studies on spatial variation of fluid inclusions show that both the steeply and gently dipping veins are consistent with the"five floors"model that may have broader applications to exploration of wolframite-quartz vein-type deposits.Recent quantitative analysis of wolframite-and quartz-hosted fluid inclusions by laser ablation inductively-coupled plasma mass spectrometry shows enhanced advantages in revealing fluid evolution,tracing the fluid source and dissecting the ore precipitation process.Further studies on wolframite-quartz vein-type W deposits to bring a deeper understanding on ore-forming fluids and the metallogenic mechanism involved.
文摘The research on Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region of Central Asia is an important and significant project. The Altay region, as a collision zone of the Early Paleozoic (500-397 Ma), and the Tianshan region, as a collision zone of the early period in the Late Paleozoic (Late Devonian-Early Carboniferous, 385-323 Ma), are all the result of nearly N-S trending shortening and collision (according to recent magnetic orientation). In the Late Devonian-Early Carboniferous period (385-323 Ma), regional NW trending faults displayed features of dextral strike-slip motion in the Altay and Junggar regions. In the Tianshan region, nearly EW-trending regional faults are motions of the thrusts. However, in the Late Carboniferous-Early Permian period (323-260 Ma), influenced by the long-distance effect induced from the Ural collision zone, those areas suffered weaker eastward compression, the existing NW trending faults converted into sinistral strike-slip in the Altay and Junggar regions, and the existing nearly E-W trending faults transferred into dextral strike-slip faults in the Tianshan region. The Rocks of those regions in the Late Carboniferous-Early Permian period (323-260 Ma) were moderately ruptured to a certain tension-shear, and thus formed a number of world famous giant endogenic metal ore deposits in the Tianshan-Altay region. As to the Central Asian continent, the most powerful collision period may not coincide with the most favorable endogenic metallogenic period. It should be treated to "the orogenic metallogeny hypothesis" with caution in that region.
文摘This paper is briefly involved in distributions of China's uranium metallogenic types, provinces, regions and belts. Eight target regions have been pointed out to be worthy of prospecting for uranium resources. The regional uranium metallogeny is discussed and great uranium potential pointed out from many aspects. Generally speaking, there are favorable conditions for uranium mineralization and good perspective to explore for uranium resources.
文摘The west sector of the northern Qilian Mountains is well-known for the Jingtieshan-type iron deposits. A new breakthrough has been made in prospecting for gold and copper in recent years. In this paper, the distribution characteristics of ore deposits in the study area are discussed from the viewpoint of tectonic evolution. It is suggested that there are 9 stages of mineralization from the Palaeoproterozoic to Indosinian. Four minerogenetic series and two minerogenetic subseries of ore deposits are recognized. Iron mineralization occurred in several stages, while most of the metals were accumulated in large amounts in the Caledonian. The enrichment and mineralization of gold is related to large-scale shear-strike-slip faults and the ascent and unloading of deep-seated fluids.
基金financially supported by the Natural National Science Foundation of China(Grant Nos.41230207,41202150, 41472192,41390441 and 41190075)
文摘Continental reconstructions in Central Asia are represented by orogenesis along some large orogenic belts in the Altaid collage (Fig. 1 ) or Central Asian Orogenic Belt (CAOB), which separate the East European and Siberian cratons to the north from the Tarim and North China cratons to the south ($eng0r et al,, 1993; Jahn et al., 2004; Windley et al., 2007; Qu et al., 2008; Xiao et al., 2010; Xiao and Santosh, 2014). The Altaid Collage was characterized by complex long tectonic and structural evolution from at least ca. 1.0 Ga to late Paleozoic-early Mesozoic with considerable continental growth (Khain et al., 2002; Jahn et al., 2004; Xiao et al., 2009, 2014; KrOner et al., 2014), followed by Cenozoic intracontinental evolution related to far-field effect of the collision of the In- dian Plate to the Eurasian Accompanying with these complex world-class ore deposits developed 2001; Goldfarb et al., 2003, 2014). Plate (Cunningham, 2005). geodynamic evolutions, many (Qin, 2000; Yakubchuk et al,2001; Goldfarb et al., 2003, 2014).
文摘The Lannigou deposit is a large-sized sedimentary rock-hosted disseminated gold (SRHDG) deposit located in the Youjiang Basin. It is hosted by the Middle Triassic turbidite. Wall rock alterations, including silicification, pyritization, arsenopyritization, carbonatization and argillization, commonly occur along fractures. PGE study demonstrates that either Permian basalts or Triassic ultrabasic intrnsives are unlikely to be the main source of gold mineralization. Coupled with the lack of other nmgmatic activity in the vicinity of the mining area, an amagmatic origin is proposed. Organic matter compositions and GC-MS analysis of the ores and host rocks show that the organics in the ores and the host rocks have a common source; the organic matter in the ores was mainly indigenous. The positive correlation between S2 and Au contents, along with the common occurrence of organic inclusions, suggest involvement of organic matter in the ore-forming process in terms of promoting Au leaching from the source rocks, making colloidal Au migration possible, as well as hydrocarbon reduction of sulphate. Geological and geochemical characteristics of the Lannigou deposit suggest that it was formed through circulation of meteoric water and probably less importantly organic bearing formation water driven by high geothermal gradient caused by late Yanshanian extension, which leached Au from the source bed, and then migrated as Au-bisnlfides and colloidal Au, culminating in deposition by reduction-adsorption and surface complexation of gold onto the growth surface of arsenlan pyrite.
基金financially supported by the Ministry of Science and Technology of China(Grant No.1999043206)the National Natural Science Foundation of China(Grant Nos.40272034 and 40133020).
文摘A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongling, Anhui Province. The major reasons for the formation of the stratabound skarn Au-S ore deposit in Tianmashan and the stratabound skarn Cu ore deposit in Datuanshan are analyzed in accordance with this contrast. The magmatic pluton in Tianmashan is rich in Au and poor in Cu, but that in Datuanshan is rich in Cu and Au. The wallrock strata in Tianmashan contain Au-bearing pyrite layers with some organic substance but those in Datuanshan contain no such layers. Moreover, the ore-forming fluids in Tianmashan are dominantly magmatic ones at the oxide and sulfide stages, but those with high content of Cu in Datuanshan are mainly groundwater fluids. In addition, differences in compositional evolution and physicochemical condition variation of the ore-forming fluids result in gradual dispersion
基金the financial support of the Presidium and Far East Branch of the Russian Academy of Sciences (Grant No.15-1-2-019)the Russian Foundation for Basic Research(Grant No.15-05-00809)+1 种基金supported by the Talent Award to M.Santosh from the 1000 Plan of the Chinese Governmentthe Foreign Expert grants from China University of Geosciences(Beijing)
文摘The Berezitovoe deposit in the Sergachi volcano-plutonic and metallogenic belt preserves evidence for polymetallic mineralization of multiple stages.The steeply dipping gamet-tourmaline-muscovite-quartz metasomatites(with K-Ar ages of 132 ± 2.9 and 127 ± 4.4 Ma) carry two distinct stages of mineralization developed at different times:(1) polymetallic mineralization and(2) gold-quartz.The deposit is located within Paleozoic gneissose granitoids of the Pikansky complex(dated as 379 ± 1.1 Ma by zircon U-Pb method) intruded by early Cretaceous porphyry-like granites of the Haikta pluton(dated as137 ± 0.67 Ma by zircon U-Pb method) and late Cretaceous dikes of porphyrites,porphyries,and lamprophyres.Evidence suggests the action of late gold-bearing hydrothermal fluids on the early polymetallic ores and the selective mobilization of some elements from these lead to redeposition together with complex sulphosalts.
基金This research was funded by the National Natural Science Foundation of China(Grant No.41872219)Key Research and Development Program of Shaanxi[2019SF-245]+2 种基金Integrated Research Project of Integrated Exploration of China Geological Survey[WKZB1911BJM300369/002]China Geological Survey Program,and Ministry of Natural Resources(Grant No.DD20179607)Fundamental Research Funds for the Central Universities,CHD(Grant No.300102271722).
文摘The Taishanmiao Au deposit is in the western part of the Ningshan-Zhenan ore field,in the South Qinling orogen.Based on geological and geochemical features,we propose that the Taishanmiao Au deposit is a magmatichydrothermal type of deposit.All samples have high SiO_(2),K_(2)O+Na_(2)O contents and differentiation index values,low CaO,MgO,P_(2)O_(5),and TiO_(2)contents,are enriched in high field-strength elements,and depleted in large ion lithophile element.The stable isotopeδ^(34)S values of pyrite vary from 6.8%-7.8%,and the H-O isotopic compositions of quartz from quartzpyrite veins indicate the ore-forming fluid is a mixture of a small amount of magmatic-hydrothermal solution and groundwater.Lead isotope ratios of pyrite and silicalite can show that the ore-forming materials were derived from a mixed source containing mantle and crustal materials.At the same time,the LA-ICP-MS U-Pb dating of monzogranite is 198.4±4.2 Ma.Combined with the regional geological background,the intracontinental extension in the late collisional orogeny and large-scale lithospheric thinning associated with mantle uplift may lead to large-scale mineralisation in the region.
文摘This paper proposes a new tectonic pattern of the deep-seated structures in China and its adjacent areas (including the T - A - B system of the Ryukyu Islands). This is based on studies of the gravity field and gravity inversion coupled with the summation of the most recent achievements in geophysical studies. From a plate-tectonic point of view, the metallogenic characteristics and their indications at depth, as well as relevant geophysical-geological characteristics of four tectonic environments of the Chinese continent are analysed, and a classification of composite metallogenic provinces and belts and prediction of metallogenic prospects are made. The author extends the Kunlun-Qilian-Qinling tectonic belt to the T-A-B system of the Ryukyu Islands through the NW deep boundary of the Hangzhou Bay, and also proposes the following basic views' the migration and superposition of tectonic environments led to the formation of a composite metallogenic system; the change in the tectonic environment resulted in the superposition of various types of mineral deposits; seismic activities and metallogeny are mutually inducing factors. These views will be helpful to a discussion on the tectonic environments and metallogenic regularities.
基金supported by the National Science and Technology Support Project of the 12th"Five-Year Plan"(Grant No.2011BAB04B06)the Fundamental Research Funds for the Central Universities of China University of Geosciences,Beijing(Grant No.2-9-2012-143)the National Natural Science Foundation of China(Grant No.41572318)
文摘The Hongdonggou Pb-Zn polymetallic ore deposit, located in the southwestern part of the Luanchuan Mo-W-Pb-Zn-Ag polymetallic ore mineralization in Henan Province, China, is an important part of the East Qinling metallogenic belt. The orebodies in the deposit, which are vein, bedded and lenticular, are mainly hosted in the syenite porphyry, and formed within the carbonate and clastic rocks of the Yuku and Qiumugou formations partially. The genesis of the deposit has previously been argued to be of hydrothermal-vein type or of skarn-hydrothermal type. In this study, we report the results of Rb-Sr isotopic dating based on sphalerites from the main orebody of the Hongdonggou Pb-Zn polymetallic ore deposit, which yield an isochron age of 135.7 ± 3.2 Ma, constraining the timing of mineralization as early Cretaceous. The age is close to those reported for the Pb-Zn deposits in the Luanchuan ore belt. The (87Sr/86Sr)i values of the sphalerites (0.71127± 0.00010) are lower than that of terrigenous silicates (0.720) and higher than the mantle (0.707), suggesting that the metallogenic components were mainly derived through crust-mantle mixing. Combining the results from this study with those from previous work, we propose that the Hongdonggou Pb-Zn polymetallic ore deposit is a hydrothermal-vein deposit associated with the early Cretaceous tectonothermal event, and the mineralization is controlled by NW- and near EW-trending faults in the Luanchuan Mo-W-Pb-Zn-Ag polymetallic ore concentration belt.
文摘The geodynamic development of Eurasian active margin is related to subduction,collision and closure of Tethys Ocean.It is divided on pre-collision and post-collision stages.The pre-collision development controlled by subduction,whereas post-collision related by orogenesis,granodiorite magmatism gold base and trace metals(Sb,W,Mo and Hg)metallogeny.The mentioned trace metals association is the geochemical indicator of first stage of post-collision development.The second stage revealed in andesite basalt,shoshonite,olivine basalt and tholeiite volcanic activity.Pre-collision stage is controlled by steady state subduction related with metamorphism and calc-alkaline volcanic activity in subaqual and island conditions of island arc setting.It is lately with steepening of subducting slab and incursion of mantle diapir transferred in interarc-backarc and minor ocean setting with shoshonite-trachyandesite and alkali olivine basalt and tholeiite volcanism and later with ophiolite volcanism,dunite-peridotite magmatism and Cu-pyrite mineralization of minor ocean setting.The pre-collision stage is developed temporally and spacially along dipping of subducted slab in the island arc setting transferring in the backarc-interarc and minor ocean settings.The similar transferring occurs laterally to dipping of slab and ascending succession.The alternation of settings shown the cycling along dipping spatial and temporal alternation of island arc,backarc and minor ocean settings.Laterally to dipping alternation is only spatial,whereas in ascending succession cycling is only temporal,localized spacially.The pre-collision development occurs in subaqual condition,whereas related to orogenesis post-collision development is mainly subaerial.
基金financially supported by the National Nature Sciences Foundation of China(Grant No.2012CB416605)the Fundamental Research Funds for the Central Universities(Grant No.2652014086)
文摘The correlation between the North China Craton(NCC) and the Indian Shield(IND) has been a hot topic in recent years,On the basis of ore deposit databases,the NCC and IND have shown broad similarity in metallogenesis from the middle Archaean to the Mesoproterozoic,The two blocks both have three major metallogenic systems:(1) the Archaean BIF metallogenic system;(2) the Paleoproterozoic Cu-Pb-Zn metallogenic system;and(3) the Mesoproterozoic Fe-Pb-Zn system,In the north margin of the NCC and the west margin of the IND,the Archaean BIF-Au-Cu-Pb-Zn deposits had the same petrogenesis and host rocks,the Paleoproterozoic Cu-Pb-Zn deposits were controlled by active belts,and the Mesoproterozoic Fe-Pb-Zn deposits were mainly related to multi-stage rifting,Matching regional mineralization patterns and geological features has established the continental assembly referred to as "NCWI",an acronym for the north margin of the NCC(NC) and the west margin of the IND(WI) during the middle Archaean to the Mesoproterozoic,In this assembly,the available geological and metallogenic data from the Eastern Block and active belts of NC fit those from the Dharwar craton and the Aravalli-DelhiVindhyan belt of WI,respectively,Moreover,the depositional model and environment of Paleoproterozoic metasedimentary manganese deposits in NCWI implied that the assembly may be located at low latitudes,where the conditions were favorable for dissolving ice and precipitating manganese deposits,
文摘The Gangdise plutonic\|volcanic arc is situated in the eastern section of the Tethys\|Himalaya metallogenic province. It is acknowledged as a “tectonic\|magmatic complex" because of its well\|developed fault and igneous activities. Intermediate to acid plutons and dikes were mainly emplaced in the Upper Cretaceous to Lower Eocene volcanic rocks. The unique tectonic position and extremely complicated evolution history of the Gangdise arc have given rise to favorable conditions for polymetal mineralization. From Xietongmen in the west to Mozhugongka in the east of the arc, Au, Cu, Pb, Zn, and Ag show large ore\|forming potentials with well overlapped and highly intensified polymetal anomalies. In the arc region, many localities, like Jiama (Cu, Pb, Zn, Au, Ag) and Qulong (Cu, Pb, Zn) in Mozhugongka county, Lakang’e (Cu, Pb, Zn, Mo) in Lazi county, Tinggong (Cu, Mo) and Chongjiang (Cu, Mo) in Nimu county, Dabu (Cu, Au) in Qushui county, and Dongga (Au, Cu) in Xietongmen county, have sound prospective for polymetals.