A reasonable classification of deposits holds great significance for identifying prospecting targets and deploying exploration. The world ’s keen demand for lithium resources has expedited the discovery of numerous n...A reasonable classification of deposits holds great significance for identifying prospecting targets and deploying exploration. The world ’s keen demand for lithium resources has expedited the discovery of numerous novel lithium resources. Given the presence of varied classification criteria for lithium resources presently, this study further ascertained and classified the lithium resources according to their occurrence modes, obtaining 10 types and 5 subtypes of lithium deposits(resources) based on endogenetic and exogenetic factors. As indicated by surveys of Cenozoic exogenetic lithium deposits in China and abroad,the formation and distribution of the deposits are primarily determined by plate collision zones, their primary material sources are linked to the anatectic magmas in the deep oceanic crust, and they were formed primarily during the Miocene and Late Paleogene. The researchers ascertained that these deposits,especially those of the salt lake, geothermal, and volcanic deposit types, are formed by unique slightly acidic magmas, tend to migrate and accumulate toward low-lying areas, and display supernormal enrichment. However, the material sources of lithium deposits(resources) of the Neopaleozoic clay subtype and the deep brine type are yet to be further identified. Given the various types and complex origins of lithium deposits(resources), which were formed due to the interactions of multiple spheres, it is recommended that the mineralization of exogenetic lithium deposits(resources) be investigated by integrating tectono-geochemistry, paleoatmospheric circulation, and salinology. So far, industrialized lithium extraction is primarily achieved in lithium deposits of the salt lake, clay, and hard rock types. The lithium extraction employs different processes, with lithium extraction from salt lake-type lithium deposits proving the most energy-saving and cost-effective.展开更多
Long-standing controversy persists over the presence and role of iron-rich melts in the formation of volcanic rock-hosted iron deposits. Conjugate iron-rich and silica-rich melt inclusions observed in thin-sections ar...Long-standing controversy persists over the presence and role of iron-rich melts in the formation of volcanic rock-hosted iron deposits. Conjugate iron-rich and silica-rich melt inclusions observed in thin-sections are considered as direct evidence for the presence of iron-rich melt, yet unequivocal outcrop-scale evidence of iron-rich melts are still lacking in volcanic rock-hosted iron deposits. Submarine volcanic rock-hosted iron deposits, which are mainly distributed in the western and eastern Tianshan Mountains in Xinjiang, are important resources of iron ores in China, but it remains unclear whether iron-rich melts have played a role in the mineralization of such iron ores. In this study, we observed abundant iron-rich agglomerates in the brecciated andesite lava of the Heijianshan submarine volcanic rock-hosted iron deposit, Eastern Tianshan, China. The iron-rich agglomerates occur as irregular and angular masses filling fractures of the host brecciated andesite lava. They show concentric potassic alteration with silicification or epidotization rims, indicative of their formation after the wall rocks. The iron-rich agglomerates have porphyritic and hyalopilitic textures, and locally display chilled margins in the contact zone with the host rocks. These features cannot be explained by hydrothermal replacement of wall rocks (brecciated andesite lava) which is free of vesicle and amygdale, rather they indicate direct crystallization of the iron-rich agglomerates from iron-rich melts. We propose that the iron-rich agglomerates were formed by open-space filling of volatile-rich iron-rich melt in fractures of the brecciated andesite lava. The iron-rich agglomerates are compositionally similar to the wall-rock brecciated andesite lava, but have much larger variation. Based on mineral assemblages, the iron-rich agglomerates are subdivided into five types, i.e., albite-magnetite type, albite-K-feldspar- magnetite type, K-feldspar-magnetite type, epidote-magnetite type and quartz-magnetite type, representing that products formed at different stages during the evolution of a magmatic-hydrothermal system. The albite-magnetite type represents the earliest crystallization product from a residual iron- rich melt; the albite-K-feldspar-magnetite and K-feldspar-magnetite types show features of magmatic- hydrothermal transition, whereas the epidote-magnetite and quartz-magnetite types represent products of hydrothermal alteration. The occurrence of iron-rich agglomerates provides macroscopic evidence for the presence of iron-rich melts in the mineralization of the Heijianshan iron deposit. It also indicates that iron mineralization of submarine volcanic rock-hosted iron deposits is genetically related to hydrothermal fluids derived from iron-rich melts.展开更多
Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain ...Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain temporal-spatial distribution characteristics. Volcanic fragments were probably derived from two different volcanic sources north and south of the North China Platform, while the magma of the two volcanic sources was probably derived from the lower crust. A new stratigraphic correlation scheme is put forward for the Benxi and Taiyuan Formations in this region on the basis of previous biostratigraphic work with the regionally widespread volcanic event layers as the marker bed for the isochronous stratigraphic correlation on a super-regional scale and in conjunction with the maximum transgressive event layers.展开更多
Large amounts of volcanic debris-avalanche deposits, which take the shape of hummocks, are distributed around the peripheries of the Laoheishan volcano and Huoshaoshan volcano in Wudalianchi World Geopark. In earlier ...Large amounts of volcanic debris-avalanche deposits, which take the shape of hummocks, are distributed around the peripheries of the Laoheishan volcano and Huoshaoshan volcano in Wudalianchi World Geopark. In earlier times, they were called "satellite volcanoes", namely, freestanding volcanoes. This paper points out that these deposits actually came from the collapse of the cones of these two volcanoes. When the lava flow spilled out at the base of the slope of the cones, the slope broke up and collapsed under the action of gravity. Later, ravines were formed on the slope. Caved slope clastics, accompanying lava flow, accumulated at the rims of the volcano cones. Although some accumulations may form very large cones, they are not volcanoes, but deposits of volcanic debris avalanches.展开更多
Upper Carboniferous-Lower Permian volcanic event deposits from two cross sections in Nanpiao, Liaoning Province, and the Daqing Mountains, Inner Mongolia, were examined by systematic rock and mineral identification, d...Upper Carboniferous-Lower Permian volcanic event deposits from two cross sections in Nanpiao, Liaoning Province, and the Daqing Mountains, Inner Mongolia, were examined by systematic rock and mineral identification, differential thermal analysis, X-ray diffraction, scanning electron microscopy and trace element and rare earth element quantitative analysis. According to the results, twelve sequences of volcanic event deposits have been distinguished from bottom to top, including 34–39 volcanic event layers. As these layers each have their own distinctive petrological, mineralogical and geochemical characteristics and were derived from the same source, they provide new evidence for further ascertaining the distribution characteristics of volcanic event deposits on the northern margin of the North China plate and carrying out the stratigraphic correlation using volcanic event layers as marker beds.展开更多
The Aqishan-Yamansu metallogenic belt(AYMB)in East Tianshan hosts abundant sub-marine volcanic-hosted iron deposits.Although there is agreement with the magmatic source of the ore-forming materials and the role of hyd...The Aqishan-Yamansu metallogenic belt(AYMB)in East Tianshan hosts abundant sub-marine volcanic-hosted iron deposits.Although there is agreement with the magmatic source of the ore-forming materials and the role of hydrothermal replacement in iron ore formation,the mineraliza-tion processes of these iron deposits remain uncertain.Three ore types are identified on the basis of the geological occurrences of minerals and the sequence of mineral in ores.The typeⅠores are characte-rized by magnetite,diopside,amphibole with a few pyrite,and chalcopyrite.The type II ores are mainly composed of magnetite,garnet,chlorite with a few pyrite,while the type III ores are mainly composed of magnetite,quartz,calcite with a few pyrite.In order to constrain the mineralization processes of these ore types,we performed iron isotopes and trace element compositions of magnetite from three typical iron deposits(Yamansu,Duotoushan and Luotuofeng).Trace element and Fe isotope investiga-tions of the three ore types reveal two major groups.The groupⅠconsists of analyses of the typeⅠandⅡores,with both showing a narrow range of positiveδ56Fe values(+0.08‰to+0.22‰for typeⅠores and+0.15‰ to+0.22‰ for typeⅡores)and plotting in the range of the ortho-magmatic field.In contrast,the group 2 is composed merely of the typeⅢores,showing a wider range of negativeδ56Fe values(-0.49‰ to-0.01‰),which is similar to the features of Fe-skarn magnetite.As shown in the binary dia-grams of magnetite trace elements and a fractionation of the Fe isotopes,different ore types were likely produced during gradually changing ore-forming stages from magmatic to hydrothermal.Collectively,the submarine volcanic-hosted iron deposits in the East Tianshan are likely the results of a continuous magmatic-hydrothermal mineralization process.展开更多
The Chagangnuoer deposit is a typical submarine volcanic rock-hosted skarn iron deposit, where orebodies mainly occur in andesitic rocks of the Dahalajunshan Formation (DF) with skams well developed around orebodies...The Chagangnuoer deposit is a typical submarine volcanic rock-hosted skarn iron deposit, where orebodies mainly occur in andesitic rocks of the Dahalajunshan Formation (DF) with skams well developed around orebodies. The volcanic rocks of the DF in the Chagangnuoer deposit display calc-alkaline characteristics. The ore-bearing andesitic rocks have high ^87Sr/^86Sr(i) (0.7058-0.7117) and low εNd(t) (-3.51 to 1.67). They probably formed through mixing of basaltic melts and the induced crustal melts. LA-ICP-MS U-Pb zircon ages of 250 and 305 Ma are obtained for the granite and granodiorite in the Chagangnuoer deposit, respectively, which are signifi- cantly younger than the timing of the skarn formation (316 Ma). These age data indicate that the granitoids have no contribution to the skarn and associated iron mineralization. This paper proposes a new genetic model for submarine volcanic rock-hosted skam iron deposits, in which the iron mineralization, skarn formation and volcanic magmatism are necessary aspects of the same system; the iron separates and concentrates from the silicate magma in the form of Fe(II) carbonate complex. While this conceptual model is largely based on observations on the Chagangnuoer deposit, it may have general significance for skam-type iron deposits associated with submarine volcanic rock sequences and warrants further testing and improvement.展开更多
基金funded by the major research program of the of National Natural Science Foundation of China entitled Metallogenic Mechanisms and Regularity of the Lithium Ore Concentration Area in the Zabuye Salt Lake, Tibet (91962219)Science and Technology Major Project of the Tibet Autonomous Region ’s Science and Techonlogy Plan (XZ202201ZD0004G01)a geological survey project of China Geological Survey (DD20230037)。
文摘A reasonable classification of deposits holds great significance for identifying prospecting targets and deploying exploration. The world ’s keen demand for lithium resources has expedited the discovery of numerous novel lithium resources. Given the presence of varied classification criteria for lithium resources presently, this study further ascertained and classified the lithium resources according to their occurrence modes, obtaining 10 types and 5 subtypes of lithium deposits(resources) based on endogenetic and exogenetic factors. As indicated by surveys of Cenozoic exogenetic lithium deposits in China and abroad,the formation and distribution of the deposits are primarily determined by plate collision zones, their primary material sources are linked to the anatectic magmas in the deep oceanic crust, and they were formed primarily during the Miocene and Late Paleogene. The researchers ascertained that these deposits,especially those of the salt lake, geothermal, and volcanic deposit types, are formed by unique slightly acidic magmas, tend to migrate and accumulate toward low-lying areas, and display supernormal enrichment. However, the material sources of lithium deposits(resources) of the Neopaleozoic clay subtype and the deep brine type are yet to be further identified. Given the various types and complex origins of lithium deposits(resources), which were formed due to the interactions of multiple spheres, it is recommended that the mineralization of exogenetic lithium deposits(resources) be investigated by integrating tectono-geochemistry, paleoatmospheric circulation, and salinology. So far, industrialized lithium extraction is primarily achieved in lithium deposits of the salt lake, clay, and hard rock types. The lithium extraction employs different processes, with lithium extraction from salt lake-type lithium deposits proving the most energy-saving and cost-effective.
基金financially supported by the Geological Survey Program of China(grants No.K1410 and DD20160346)the National Natural Foundation of China(grants No.41672078 and 41402067)
文摘Long-standing controversy persists over the presence and role of iron-rich melts in the formation of volcanic rock-hosted iron deposits. Conjugate iron-rich and silica-rich melt inclusions observed in thin-sections are considered as direct evidence for the presence of iron-rich melt, yet unequivocal outcrop-scale evidence of iron-rich melts are still lacking in volcanic rock-hosted iron deposits. Submarine volcanic rock-hosted iron deposits, which are mainly distributed in the western and eastern Tianshan Mountains in Xinjiang, are important resources of iron ores in China, but it remains unclear whether iron-rich melts have played a role in the mineralization of such iron ores. In this study, we observed abundant iron-rich agglomerates in the brecciated andesite lava of the Heijianshan submarine volcanic rock-hosted iron deposit, Eastern Tianshan, China. The iron-rich agglomerates occur as irregular and angular masses filling fractures of the host brecciated andesite lava. They show concentric potassic alteration with silicification or epidotization rims, indicative of their formation after the wall rocks. The iron-rich agglomerates have porphyritic and hyalopilitic textures, and locally display chilled margins in the contact zone with the host rocks. These features cannot be explained by hydrothermal replacement of wall rocks (brecciated andesite lava) which is free of vesicle and amygdale, rather they indicate direct crystallization of the iron-rich agglomerates from iron-rich melts. We propose that the iron-rich agglomerates were formed by open-space filling of volatile-rich iron-rich melt in fractures of the brecciated andesite lava. The iron-rich agglomerates are compositionally similar to the wall-rock brecciated andesite lava, but have much larger variation. Based on mineral assemblages, the iron-rich agglomerates are subdivided into five types, i.e., albite-magnetite type, albite-K-feldspar- magnetite type, K-feldspar-magnetite type, epidote-magnetite type and quartz-magnetite type, representing that products formed at different stages during the evolution of a magmatic-hydrothermal system. The albite-magnetite type represents the earliest crystallization product from a residual iron- rich melt; the albite-K-feldspar-magnetite and K-feldspar-magnetite types show features of magmatic- hydrothermal transition, whereas the epidote-magnetite and quartz-magnetite types represent products of hydrothermal alteration. The occurrence of iron-rich agglomerates provides macroscopic evidence for the presence of iron-rich melts in the mineralization of the Heijianshan iron deposit. It also indicates that iron mineralization of submarine volcanic rock-hosted iron deposits is genetically related to hydrothermal fluids derived from iron-rich melts.
基金This study was supported by the National Natural Science Foundation of China Grant No. 4880102
文摘Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain temporal-spatial distribution characteristics. Volcanic fragments were probably derived from two different volcanic sources north and south of the North China Platform, while the magma of the two volcanic sources was probably derived from the lower crust. A new stratigraphic correlation scheme is put forward for the Benxi and Taiyuan Formations in this region on the basis of previous biostratigraphic work with the regionally widespread volcanic event layers as the marker bed for the isochronous stratigraphic correlation on a super-regional scale and in conjunction with the maximum transgressive event layers.
文摘Large amounts of volcanic debris-avalanche deposits, which take the shape of hummocks, are distributed around the peripheries of the Laoheishan volcano and Huoshaoshan volcano in Wudalianchi World Geopark. In earlier times, they were called "satellite volcanoes", namely, freestanding volcanoes. This paper points out that these deposits actually came from the collapse of the cones of these two volcanoes. When the lava flow spilled out at the base of the slope of the cones, the slope broke up and collapsed under the action of gravity. Later, ravines were formed on the slope. Caved slope clastics, accompanying lava flow, accumulated at the rims of the volcano cones. Although some accumulations may form very large cones, they are not volcanoes, but deposits of volcanic debris avalanches.
基金This research was supported by National Natural Science Foundation of China grant 49762094.
文摘Upper Carboniferous-Lower Permian volcanic event deposits from two cross sections in Nanpiao, Liaoning Province, and the Daqing Mountains, Inner Mongolia, were examined by systematic rock and mineral identification, differential thermal analysis, X-ray diffraction, scanning electron microscopy and trace element and rare earth element quantitative analysis. According to the results, twelve sequences of volcanic event deposits have been distinguished from bottom to top, including 34–39 volcanic event layers. As these layers each have their own distinctive petrological, mineralogical and geochemical characteristics and were derived from the same source, they provide new evidence for further ascertaining the distribution characteristics of volcanic event deposits on the northern margin of the North China plate and carrying out the stratigraphic correlation using volcanic event layers as marker beds.
基金This study was financially supported by National Natural Science Foundation of China(No.41672078)the China Geological Survey(No.DD20190606).
文摘The Aqishan-Yamansu metallogenic belt(AYMB)in East Tianshan hosts abundant sub-marine volcanic-hosted iron deposits.Although there is agreement with the magmatic source of the ore-forming materials and the role of hydrothermal replacement in iron ore formation,the mineraliza-tion processes of these iron deposits remain uncertain.Three ore types are identified on the basis of the geological occurrences of minerals and the sequence of mineral in ores.The typeⅠores are characte-rized by magnetite,diopside,amphibole with a few pyrite,and chalcopyrite.The type II ores are mainly composed of magnetite,garnet,chlorite with a few pyrite,while the type III ores are mainly composed of magnetite,quartz,calcite with a few pyrite.In order to constrain the mineralization processes of these ore types,we performed iron isotopes and trace element compositions of magnetite from three typical iron deposits(Yamansu,Duotoushan and Luotuofeng).Trace element and Fe isotope investiga-tions of the three ore types reveal two major groups.The groupⅠconsists of analyses of the typeⅠandⅡores,with both showing a narrow range of positiveδ56Fe values(+0.08‰to+0.22‰for typeⅠores and+0.15‰ to+0.22‰ for typeⅡores)and plotting in the range of the ortho-magmatic field.In contrast,the group 2 is composed merely of the typeⅢores,showing a wider range of negativeδ56Fe values(-0.49‰ to-0.01‰),which is similar to the features of Fe-skarn magnetite.As shown in the binary dia-grams of magnetite trace elements and a fractionation of the Fe isotopes,different ore types were likely produced during gradually changing ore-forming stages from magmatic to hydrothermal.Collectively,the submarine volcanic-hosted iron deposits in the East Tianshan are likely the results of a continuous magmatic-hydrothermal mineralization process.
基金supported by two geological survey projects of China Geological Survey Departments and Offices (1212011121092, 1212011220928)
文摘The Chagangnuoer deposit is a typical submarine volcanic rock-hosted skarn iron deposit, where orebodies mainly occur in andesitic rocks of the Dahalajunshan Formation (DF) with skams well developed around orebodies. The volcanic rocks of the DF in the Chagangnuoer deposit display calc-alkaline characteristics. The ore-bearing andesitic rocks have high ^87Sr/^86Sr(i) (0.7058-0.7117) and low εNd(t) (-3.51 to 1.67). They probably formed through mixing of basaltic melts and the induced crustal melts. LA-ICP-MS U-Pb zircon ages of 250 and 305 Ma are obtained for the granite and granodiorite in the Chagangnuoer deposit, respectively, which are signifi- cantly younger than the timing of the skarn formation (316 Ma). These age data indicate that the granitoids have no contribution to the skarn and associated iron mineralization. This paper proposes a new genetic model for submarine volcanic rock-hosted skam iron deposits, in which the iron mineralization, skarn formation and volcanic magmatism are necessary aspects of the same system; the iron separates and concentrates from the silicate magma in the form of Fe(II) carbonate complex. While this conceptual model is largely based on observations on the Chagangnuoer deposit, it may have general significance for skam-type iron deposits associated with submarine volcanic rock sequences and warrants further testing and improvement.