The Maoling gold deposit, one of the large gold deposits in eastern Liaoning Province, NE China, is an ar- senopyrite-disseminated gold deposit with a resource of ap- proximately 25 t Au and an average Au grade of 3.2...The Maoling gold deposit, one of the large gold deposits in eastern Liaoning Province, NE China, is an ar- senopyrite-disseminated gold deposit with a resource of ap- proximately 25 t Au and an average Au grade of 3.2 g/t. Six arsenopyrites closely related to Au mineralization of the Maoling gold deposit are dated by Re-Os technique and de- fine a Re-Os isochron with an age of 2316±140 Ma, which suggests that the deposit was formed in the Paleoproterozoic era rather than in the Indosinian period as some early re- searchers suggested. High initial 187Os/188Os ratio of 1.32±0.48 indicates a crustal derivation of the ore-forming material of the deposit, which may be derived from rocks of the Gaixian formation of the Liaohe Group. Furthermore, the result also implies that the age of the Gaixian Formation in the Maoling district is older than 2316±140 Ma.展开更多
The time gap between diagenesis and mineralization (TGDM) for comagmatic gold deposits (CGD) plays an important role in confirming the genetic relationship between gold deposits and their related intrusions. With the ...The time gap between diagenesis and mineralization (TGDM) for comagmatic gold deposits (CGD) plays an important role in confirming the genetic relationship between gold deposits and their related intrusions. With the help of preciously published isotopic ages of some typical gold deposits and their related rocks in China,the authors have discussed and quantified the distribution characteristics and scope of the TGDM. Statistical analyses and Kolmogorov tests showed that mineralizing events are either contemporaneous with or slightly postdate their cognate magma. The TGDM conforms with normal distributions at a 0.05 confidence level and clusters between 0 and 16.0 Ma with a mean of 7.0 Ma. Thus,if the TGDM of CGD is less than 16.0 Ma,it is reasonable to consider,with the aid of other evidence,the possibility of its comagmatic genetic affiliation. The authors also emphasized that to get a precise time gap it is necessary to strengthen the diagenesis-mineralization geological background of the deposits studied,and to pay attention to the study of time gap in combination with trace elements and isotope tracing.展开更多
A large number of the Carlin-type gold deposits occur in the Longtan Formation in southwestern Guizhou Province.The Long-tan Formation contains abundant basalt,tuff and siliceous rocks.All rocks of the Longtan Formati...A large number of the Carlin-type gold deposits occur in the Longtan Formation in southwestern Guizhou Province.The Long-tan Formation contains abundant basalt,tuff and siliceous rocks.All rocks of the Longtan Formation are enriched in gold,which were deposited in a limited platform environment in the transition zone from marine to continental.The process of sedimentation was accompanied by the eruption of Emeishan basalt and hydrothermal deposition controlled by co-sedimentary submarine deep faults in the west,which led to the formation of a peculiar gold-bearing formation with coal series strata.This formation controlled the occurrence of the Carlin-type gold deposits in southwestern Guizhou Province.In response to the remobilization of the Emei mantle plume during the Yanshanian period,As,Au and other ore-forming materials were continuously extracted by deeply circulating waters from the Emeishan basalt and coal seams,thereafter forming ore-forming hydrothermal solutions.When these elements were transported in the coal seams,large amounts of As,Au and other elements were enriched in pyrite within the coal seams,thus forming high-As coal and Carlin-type gold deposits in the Longtan Formation coal series strata.展开更多
基金supported by the State Key Basic Research Program(Grant No.01999043201)the Hefei Analysis Foundation of Chinese Academy of Sciences.
文摘The Maoling gold deposit, one of the large gold deposits in eastern Liaoning Province, NE China, is an ar- senopyrite-disseminated gold deposit with a resource of ap- proximately 25 t Au and an average Au grade of 3.2 g/t. Six arsenopyrites closely related to Au mineralization of the Maoling gold deposit are dated by Re-Os technique and de- fine a Re-Os isochron with an age of 2316±140 Ma, which suggests that the deposit was formed in the Paleoproterozoic era rather than in the Indosinian period as some early re- searchers suggested. High initial 187Os/188Os ratio of 1.32±0.48 indicates a crustal derivation of the ore-forming material of the deposit, which may be derived from rocks of the Gaixian formation of the Liaohe Group. Furthermore, the result also implies that the age of the Gaixian Formation in the Maoling district is older than 2316±140 Ma.
基金supported by the Doctoral Education Program Fund of the Ministry of Education,Peoples Republic of China (No. 20040491502)
文摘The time gap between diagenesis and mineralization (TGDM) for comagmatic gold deposits (CGD) plays an important role in confirming the genetic relationship between gold deposits and their related intrusions. With the help of preciously published isotopic ages of some typical gold deposits and their related rocks in China,the authors have discussed and quantified the distribution characteristics and scope of the TGDM. Statistical analyses and Kolmogorov tests showed that mineralizing events are either contemporaneous with or slightly postdate their cognate magma. The TGDM conforms with normal distributions at a 0.05 confidence level and clusters between 0 and 16.0 Ma with a mean of 7.0 Ma. Thus,if the TGDM of CGD is less than 16.0 Ma,it is reasonable to consider,with the aid of other evidence,the possibility of its comagmatic genetic affiliation. The authors also emphasized that to get a precise time gap it is necessary to strengthen the diagenesis-mineralization geological background of the deposits studied,and to pay attention to the study of time gap in combination with trace elements and isotope tracing.
文摘A large number of the Carlin-type gold deposits occur in the Longtan Formation in southwestern Guizhou Province.The Long-tan Formation contains abundant basalt,tuff and siliceous rocks.All rocks of the Longtan Formation are enriched in gold,which were deposited in a limited platform environment in the transition zone from marine to continental.The process of sedimentation was accompanied by the eruption of Emeishan basalt and hydrothermal deposition controlled by co-sedimentary submarine deep faults in the west,which led to the formation of a peculiar gold-bearing formation with coal series strata.This formation controlled the occurrence of the Carlin-type gold deposits in southwestern Guizhou Province.In response to the remobilization of the Emei mantle plume during the Yanshanian period,As,Au and other ore-forming materials were continuously extracted by deeply circulating waters from the Emeishan basalt and coal seams,thereafter forming ore-forming hydrothermal solutions.When these elements were transported in the coal seams,large amounts of As,Au and other elements were enriched in pyrite within the coal seams,thus forming high-As coal and Carlin-type gold deposits in the Longtan Formation coal series strata.
