Hydrothermal activity from a hydrothermal circulatory system is a special geological event, it is of importance to the formation of some massive sulfide deposits (hydrothermal deposits). The Authors think that Jiama p...Hydrothermal activity from a hydrothermal circulatory system is a special geological event, it is of importance to the formation of some massive sulfide deposits (hydrothermal deposits). The Authors think that Jiama polymetallic ore deposit in Gangdise tectonic zone, Tibet is a special skarn deposit i.e. a “hydrothermal\|metasomatic skarn deposit" bound up with benthonic hydrothermal circulatory system. Its important characteristics are as follows: 1 Evolution of the Gangdise island arc in studied area may be divided into three stages Middle Jurassic volcanic arc stage; Middle—Late Jurassic and Early Cretaceous inter arc sedimentary basin stage; and Eogene magmatic arc stage. The deposit is confined to the inter arc sedimentary basin. Existing data indicate that the volcanic arc provided Jiama deposit with abundant ore\|forming material; the inter arc sedimentary basin provided Jiama deposit with absolutely necessary space; the magmatic arc created reconcentration condition for the Jiama deposit.展开更多
Hydrothermal cobalt deposits provide a valuable example in understanding the relationship between mafic magmatism and mineralization.Three main types of hydrothermal cobalt ore deposits have been recognized in the Alt...Hydrothermal cobalt deposits provide a valuable example in understanding the relationship between mafic magmatism and mineralization.Three main types of hydrothermal cobalt ore deposits have been recognized in the Altay-Sayan fold belt(Russia), which are Ni-Co-arsenic(Ni-Co-As),Co-sulfoarsenic (Co-As),and Cu-Co-sulfoarsenic-sulfosaltic(Cu-Co -As).Cobalt mineralization in this district is characterized by well zonation,commonly with the following sequence:Co-sulfoarsenic ores in metasomatic rocks→Ni-Co-As mineralization in carbonate展开更多
The Jinchuan magmatic Ni-Cu deposit,located in the Longshou Mountain region,is the largest producer of Ni and Cu in China,with mineralization being related to mafic and ultramafic magmatism.Previous studies have shown...The Jinchuan magmatic Ni-Cu deposit,located in the Longshou Mountain region,is the largest producer of Ni and Cu in China,with mineralization being related to mafic and ultramafic magmatism.Previous studies have shown that the Longshou Mountain was combined with the Qilian Mountains before Neoproterozoic,and was separated from each other due to the opening of late Qilian oceanic basin in the Paleozoic.The relict Precambrian microcontinents of the Longshou Mountain and Qilian Mountain展开更多
Longtoushan Sn-polymetal deposit is a large-scale deposit of high-tenor. The ore-bodies occur in reef limestone of middle Devonian. There is much anthraxolite in reef limestone and ore-bodies. The anthraxolite is the ...Longtoushan Sn-polymetal deposit is a large-scale deposit of high-tenor. The ore-bodies occur in reef limestone of middle Devonian. There is much anthraxolite in reef limestone and ore-bodies. The anthraxolite is the postmature result of oil-gas' thermal metamorphism. The close relationship of anthraxolite and Sn-polymetal deposit reveals the space-time relation between oil-gas evolution and Sn-polymetal mineralization. Sulfur isotope of Longtoushan deposit is close to oil's sulfur in Devonian, which indicates obvious relationship between the sulfur's source of deposit and oil-gas' activity. The forming of Longtoushan deposit relates to exhalative-sedimentary mineralization in Devonian. Because of the favorable hydrocarbon-forming condition of Longtoushan reef and surrounding basin facies' black shale and peat, coupling of ore-formation and hydrocarbon-forming occurs in seabed's hydrothermal convection. The distributing of ore-forming elements indicates the presence of hydrothermal convection system. The thermal fluid containing organic matters conduces to Sn-polymetal elements' activation and transfer, and provides catalyzing condition to the transforming from SO42- to S2-. The erosion action of brine containing organic acid to reef limestone induces the growing of crannies and karst's caverns, which provides advantageous space to Sn-polymetal mineralization. The heat source of mineralization provides thermocatalysis condition to hydrocarbon-forming. When the circulatory fluid containing oil-gas enters the high-temperature region(＞150 ℃ ), the oil-gas is decomposed and anthraxolite comes into being.展开更多
文摘Hydrothermal activity from a hydrothermal circulatory system is a special geological event, it is of importance to the formation of some massive sulfide deposits (hydrothermal deposits). The Authors think that Jiama polymetallic ore deposit in Gangdise tectonic zone, Tibet is a special skarn deposit i.e. a “hydrothermal\|metasomatic skarn deposit" bound up with benthonic hydrothermal circulatory system. Its important characteristics are as follows: 1 Evolution of the Gangdise island arc in studied area may be divided into three stages Middle Jurassic volcanic arc stage; Middle—Late Jurassic and Early Cretaceous inter arc sedimentary basin stage; and Eogene magmatic arc stage. The deposit is confined to the inter arc sedimentary basin. Existing data indicate that the volcanic arc provided Jiama deposit with abundant ore\|forming material; the inter arc sedimentary basin provided Jiama deposit with absolutely necessary space; the magmatic arc created reconcentration condition for the Jiama deposit.
文摘Hydrothermal cobalt deposits provide a valuable example in understanding the relationship between mafic magmatism and mineralization.Three main types of hydrothermal cobalt ore deposits have been recognized in the Altay-Sayan fold belt(Russia), which are Ni-Co-arsenic(Ni-Co-As),Co-sulfoarsenic (Co-As),and Cu-Co-sulfoarsenic-sulfosaltic(Cu-Co -As).Cobalt mineralization in this district is characterized by well zonation,commonly with the following sequence:Co-sulfoarsenic ores in metasomatic rocks→Ni-Co-As mineralization in carbonate
文摘The Jinchuan magmatic Ni-Cu deposit,located in the Longshou Mountain region,is the largest producer of Ni and Cu in China,with mineralization being related to mafic and ultramafic magmatism.Previous studies have shown that the Longshou Mountain was combined with the Qilian Mountains before Neoproterozoic,and was separated from each other due to the opening of late Qilian oceanic basin in the Paleozoic.The relict Precambrian microcontinents of the Longshou Mountain and Qilian Mountain
文摘Longtoushan Sn-polymetal deposit is a large-scale deposit of high-tenor. The ore-bodies occur in reef limestone of middle Devonian. There is much anthraxolite in reef limestone and ore-bodies. The anthraxolite is the postmature result of oil-gas' thermal metamorphism. The close relationship of anthraxolite and Sn-polymetal deposit reveals the space-time relation between oil-gas evolution and Sn-polymetal mineralization. Sulfur isotope of Longtoushan deposit is close to oil's sulfur in Devonian, which indicates obvious relationship between the sulfur's source of deposit and oil-gas' activity. The forming of Longtoushan deposit relates to exhalative-sedimentary mineralization in Devonian. Because of the favorable hydrocarbon-forming condition of Longtoushan reef and surrounding basin facies' black shale and peat, coupling of ore-formation and hydrocarbon-forming occurs in seabed's hydrothermal convection. The distributing of ore-forming elements indicates the presence of hydrothermal convection system. The thermal fluid containing organic matters conduces to Sn-polymetal elements' activation and transfer, and provides catalyzing condition to the transforming from SO42- to S2-. The erosion action of brine containing organic acid to reef limestone induces the growing of crannies and karst's caverns, which provides advantageous space to Sn-polymetal mineralization. The heat source of mineralization provides thermocatalysis condition to hydrocarbon-forming. When the circulatory fluid containing oil-gas enters the high-temperature region(＞150 ℃ ), the oil-gas is decomposed and anthraxolite comes into being.
