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 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
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
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 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
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
As a typical Palaeozoic island arc system, the eastern Tianshan area, Xinjiang, is different from eastern China but similar to the Meso-Cenozoic island arc metallogenic provinces along the coast of the Pacific Ocean i...As a typical Palaeozoic island arc system, the eastern Tianshan area, Xinjiang, is different from eastern China but similar to the Meso-Cenozoic island arc metallogenic provinces along the coast of the Pacific Ocean in metallogenic environment, geology and geochemistry. Three types of gold deposits, ductile shear zone-hosted gold deposits (Kanggur'), magmatic hydrothermal gold deposits (Jinwozi) and volcanic- or subvolcanic-hosted gold deposits (Xitan and Mazhuangshan), have been identified in this area. Regionally, gold deposits are structurally controlled by the Kanggur Tag ductile shear zone, Shaquanzi fault, Hongliuhe fault and Yamansu fault. Generally, gold mineralization occurs in the transition zones from volcanic rocks to sedimentary rocks. The horizon bearing well-developed jasper is an important indicator for gold mineralization. Each of the three types of gold deposits has its distinctive metallogenic background and geological-geochemical characteristics.展开更多
Following the paper entitled A Preliminary Proposal on Crustobody Geotectonics presented by the first author to the 30th IGC in 1996, this paper further extends and elucidates the concept of crustobody in order to mak...Following the paper entitled A Preliminary Proposal on Crustobody Geotectonics presented by the first author to the 30th IGC in 1996, this paper further extends and elucidates the concept of crustobody in order to make a unifying study of the evolution and motion of crustal structures and to understand the law governing the formation and development of the earth' crust. In this paper the characteristics of crustobody evolution-motion are given. The authors lay emphasis on the relationship between crustobody evolution-motion and tectonic metallogeny. In the end, a multiple dynamic system of the crustobody evolution-motion is discussed from internal and external dynamic forces, and the mantle creep in internal dynamic factors is paid special attention to.展开更多
A series of experimental geochemical studies have been done to confirm the organic metallogenic mechanism of weathering crust RE deposits. It has been concluded that: (1) Rich REbearing weathering crusts contain abund...A series of experimental geochemical studies have been done to confirm the organic metallogenic mechanism of weathering crust RE deposits. It has been concluded that: (1) Rich REbearing weathering crusts contain abundant organisms such as monoacids, diacids and nonacid compounds. Varieties and quantities of the organisms decrease from the upper to the lower of the profile. Humic acids are mainly fulvic acids, which are characterized by containing conjugated π system, carboxylic group, hydroxyl group and only a few nitrogenous groups. No obvious benzene ring has been found. (2) The upper part of the weathering crust contains a great deal of microorganisms, of which the varieties and quantities decrease from the upper to the lower of the profile. No microorganism has been found in the deep part of the profile. The microorganisms and their metabolites such as aminoacids, shortchain acids and organic compounds with small molecular weights can form water soluble RE complexes, which accelerate the RE transportation from original rocks and precipitation states to watersoluble states and thus provide prerequisites for retransportation and reaccumulation of RE. (3) Medium and longchain acids can form REnAm(OH)x(H2O)y type mixedligand polynuclear RE complexes, which devoted to the RE accumulation, whereas shortchain acids and aminoacids can form not only mixedligand complexes with RE, but also water soluble complex ions, which also devoted to the transport and accumulation of RE. (4) The fulvic acids are very soluble in water. They are apt to be mobile in the weathering crust and are able to form soluble complex ions and insoluble mixedligand polynuclear complexes with RE at normal temperature and atmospheric pressure and pH4~6. The composition of these complexes varies with different conditions of the weathering crust. (5) All the organic acids, fulvic acids and microorgaisms have contributed to keeping constant pH condition of the weathering crust. (6) Complexes consisting of clays, RE(Al, Fe……) and fulvic acids have been found in the weathering crust and a bonding pattern has been preliminarily studied. As a conclusion, the dissolution, transport and accumulaiton of REE during weathering is a organic and inorganic interacted process.展开更多
Giant mafic dyke swarms are a key component of the feeder system of Large Igneous Provinces(LIPs),large volume(>0.1 Mkm;;frequently above>1 M km;),mainly mafic(-ultramafic)magmatic events of intraplate aff...Giant mafic dyke swarms are a key component of the feeder system of Large Igneous Provinces(LIPs),large volume(>0.1 Mkm;;frequently above>1 M km;),mainly mafic(-ultramafic)magmatic events of intraplate affinity.展开更多
Three logarithmic linear equations between D_(Me)^(V/L) and [m_(NaCl)], and the relationship of D_(Me)^(V/L) versus F/Cl or K/Na mole ratios have been established by the experiments of the partitioning of Pb and Zn be...Three logarithmic linear equations between D_(Me)^(V/L) and [m_(NaCl)], and the relationship of D_(Me)^(V/L) versus F/Cl or K/Na mole ratios have been established by the experiments of the partitioning of Pb and Zn between granitic silicate melt and aqueous fluid. These results have been used to quantitatively study some essential problems, such as the possibility and degree of Pb-Zn mineralization in the system of granitic magma and hydrothermal fluid, and the influence of the relative contents of alkali and volatiles on the Pb-Zn mineralization in the same system. Some new points have been put forward in this paper.展开更多
Based on digital elevation models SRTM03 and SRTM30_Plus (Shuttle Radar Topography Mission Survey) the technique for detecting major structural elements and elucidating details of the geologic structure including disc...Based on digital elevation models SRTM03 and SRTM30_Plus (Shuttle Radar Topography Mission Survey) the technique for detecting major structural elements and elucidating details of the geologic structure including discrimination of linear structures and texture features is elaborated. The computation of the modulus of the first derivative by the co- ordinate, i.展开更多
There are three diwa regions in South Siberia and West Mongolia. One of them is arranged in West Transbaikalia and was formed from Devonian till Carboniferous periods. Numerous deposits of tungsten , tin, molybdenum, ...There are three diwa regions in South Siberia and West Mongolia. One of them is arranged in West Transbaikalia and was formed from Devonian till Carboniferous periods. Numerous deposits of tungsten , tin, molybdenum, REE, synnyrites, urtites are genetically linked with intrusive rocks. The next diwa region is arranged in North Mongolia and South Buryatia. This diwa region was formed in the Late Paleozoic time. The deposits of molybdenum, tungsten, boron, iron, copper, beryllium are genetically linked with magmatic rocks of this region. The third region was formed in Devonian in West Mongollia. The magmatic rocks of this region are represented by alkaline granitoids. Some deposits of REE and rare metals are linked with these rocks.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 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.
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 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 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.
文摘As a typical Palaeozoic island arc system, the eastern Tianshan area, Xinjiang, is different from eastern China but similar to the Meso-Cenozoic island arc metallogenic provinces along the coast of the Pacific Ocean in metallogenic environment, geology and geochemistry. Three types of gold deposits, ductile shear zone-hosted gold deposits (Kanggur'), magmatic hydrothermal gold deposits (Jinwozi) and volcanic- or subvolcanic-hosted gold deposits (Xitan and Mazhuangshan), have been identified in this area. Regionally, gold deposits are structurally controlled by the Kanggur Tag ductile shear zone, Shaquanzi fault, Hongliuhe fault and Yamansu fault. Generally, gold mineralization occurs in the transition zones from volcanic rocks to sedimentary rocks. The horizon bearing well-developed jasper is an important indicator for gold mineralization. Each of the three types of gold deposits has its distinctive metallogenic background and geological-geochemical characteristics.
基金This paper was financially supported by the Academician Foundation of the Chinese Academy of Sciencesgrant KZ952-J1-007.
文摘Following the paper entitled A Preliminary Proposal on Crustobody Geotectonics presented by the first author to the 30th IGC in 1996, this paper further extends and elucidates the concept of crustobody in order to make a unifying study of the evolution and motion of crustal structures and to understand the law governing the formation and development of the earth' crust. In this paper the characteristics of crustobody evolution-motion are given. The authors lay emphasis on the relationship between crustobody evolution-motion and tectonic metallogeny. In the end, a multiple dynamic system of the crustobody evolution-motion is discussed from internal and external dynamic forces, and the mantle creep in internal dynamic factors is paid special attention to.
文摘A series of experimental geochemical studies have been done to confirm the organic metallogenic mechanism of weathering crust RE deposits. It has been concluded that: (1) Rich REbearing weathering crusts contain abundant organisms such as monoacids, diacids and nonacid compounds. Varieties and quantities of the organisms decrease from the upper to the lower of the profile. Humic acids are mainly fulvic acids, which are characterized by containing conjugated π system, carboxylic group, hydroxyl group and only a few nitrogenous groups. No obvious benzene ring has been found. (2) The upper part of the weathering crust contains a great deal of microorganisms, of which the varieties and quantities decrease from the upper to the lower of the profile. No microorganism has been found in the deep part of the profile. The microorganisms and their metabolites such as aminoacids, shortchain acids and organic compounds with small molecular weights can form water soluble RE complexes, which accelerate the RE transportation from original rocks and precipitation states to watersoluble states and thus provide prerequisites for retransportation and reaccumulation of RE. (3) Medium and longchain acids can form REnAm(OH)x(H2O)y type mixedligand polynuclear RE complexes, which devoted to the RE accumulation, whereas shortchain acids and aminoacids can form not only mixedligand complexes with RE, but also water soluble complex ions, which also devoted to the transport and accumulation of RE. (4) The fulvic acids are very soluble in water. They are apt to be mobile in the weathering crust and are able to form soluble complex ions and insoluble mixedligand polynuclear complexes with RE at normal temperature and atmospheric pressure and pH4~6. The composition of these complexes varies with different conditions of the weathering crust. (5) All the organic acids, fulvic acids and microorgaisms have contributed to keeping constant pH condition of the weathering crust. (6) Complexes consisting of clays, RE(Al, Fe……) and fulvic acids have been found in the weathering crust and a bonding pattern has been preliminarily studied. As a conclusion, the dissolution, transport and accumulaiton of REE during weathering is a organic and inorganic interacted process.
文摘Giant mafic dyke swarms are a key component of the feeder system of Large Igneous Provinces(LIPs),large volume(>0.1 Mkm;;frequently above>1 M km;),mainly mafic(-ultramafic)magmatic events of intraplate affinity.
文摘Three logarithmic linear equations between D_(Me)^(V/L) and [m_(NaCl)], and the relationship of D_(Me)^(V/L) versus F/Cl or K/Na mole ratios have been established by the experiments of the partitioning of Pb and Zn between granitic silicate melt and aqueous fluid. These results have been used to quantitatively study some essential problems, such as the possibility and degree of Pb-Zn mineralization in the system of granitic magma and hydrothermal fluid, and the influence of the relative contents of alkali and volatiles on the Pb-Zn mineralization in the same system. Some new points have been put forward in this paper.
文摘Based on digital elevation models SRTM03 and SRTM30_Plus (Shuttle Radar Topography Mission Survey) the technique for detecting major structural elements and elucidating details of the geologic structure including discrimination of linear structures and texture features is elaborated. The computation of the modulus of the first derivative by the co- ordinate, i.
文摘There are three diwa regions in South Siberia and West Mongolia. One of them is arranged in West Transbaikalia and was formed from Devonian till Carboniferous periods. Numerous deposits of tungsten , tin, molybdenum, REE, synnyrites, urtites are genetically linked with intrusive rocks. The next diwa region is arranged in North Mongolia and South Buryatia. This diwa region was formed in the Late Paleozoic time. The deposits of molybdenum, tungsten, boron, iron, copper, beryllium are genetically linked with magmatic rocks of this region. The third region was formed in Devonian in West Mongollia. The magmatic rocks of this region are represented by alkaline granitoids. Some deposits of REE and rare metals are linked with these rocks.