Veined gold deposit is product of crustal evolution in special space and special time.It has close relations between the product of veined gold deposit and the formation mechanism (process of mineralization geodynamic...Veined gold deposit is product of crustal evolution in special space and special time.It has close relations between the product of veined gold deposit and the formation mechanism (process of mineralization geodynamics),It has special geological significance in the aspect of source of metallogenic material and metallogenic fluid,migration and precipitation, especially in vein gold deposit of structure boundary.This pater discusses four aspects,i.e. The geodynamic background,source of metallogenic fluid,fluid migration mechanism and structural position of deposits.The concluding remarks are given as follows. 1\ The Pre Cambrian metamorphic complexes emerged extensively in the Wutaishan Hengshan area, more than 60% of those are granitic rock, as the oldest continential crust of crystalline basement they all have the characteristics of deformation and gneiss, and many of them were formed in 2500～2700 Ma, in them some high rank deformed super crust inclusions, or relicts of different rock facies showing 2800～2900 Ma or earlier ages. Through the comphrehensive analysis of large rock chemical data on the relevant diagram about their characteristics, it reflects that not only the granitic rock has two different characteristics of rock series and regionalization but also shows several distinct source tendencies. Itsuggests that the large emergence of granitic rock in Archean era in the area is related to certain collision mechanism, thus resulted in the connection of the landmass, north to Hengshan and the landmass of Bupin,and so completed the cratonization of North China platform. The formation of granitic rock in early Proterozoic era is relevant to rifting which belongs to the genetic series of later orogenic to postorogenic period. 2\ The zonal super crust rock series that stretches in NEE direction on the Archaeozoic crystalline basement in Wutaishan and its vicinity area is called Wutai Group and Hutuo Group. The Wutai Group is mainly consisted of mafic volcanic rock, and uncomformably was under laid the Hutuo展开更多
Archean greenstone belts and their possible inclusion of fragments of ophiolites is an im-portant research subject, since it is correlated with the nature of early oceanic crust, and can yield in-formation on the natu...Archean greenstone belts and their possible inclusion of fragments of ophiolites is an im-portant research subject, since it is correlated with the nature of early oceanic crust, and can yield in-formation on the nature of early planetary lithospheres, the origin of TTG （tonalite-trondhjemite-granodiorite） continental crust, the formation of early cratons and continents, and is related to when plate tectonics started in the Earth＇s evolutionary history. This article briefly reviews the North China craton＇s Archean ophiolite argument and proposes further studies aimed at understanding the genera- tion of greenstone belts and Archean ophiolites, and suggests some key scientific questions that remain to be answered.展开更多
文摘Veined gold deposit is product of crustal evolution in special space and special time.It has close relations between the product of veined gold deposit and the formation mechanism (process of mineralization geodynamics),It has special geological significance in the aspect of source of metallogenic material and metallogenic fluid,migration and precipitation, especially in vein gold deposit of structure boundary.This pater discusses four aspects,i.e. The geodynamic background,source of metallogenic fluid,fluid migration mechanism and structural position of deposits.The concluding remarks are given as follows. 1\ The Pre Cambrian metamorphic complexes emerged extensively in the Wutaishan Hengshan area, more than 60% of those are granitic rock, as the oldest continential crust of crystalline basement they all have the characteristics of deformation and gneiss, and many of them were formed in 2500～2700 Ma, in them some high rank deformed super crust inclusions, or relicts of different rock facies showing 2800～2900 Ma or earlier ages. Through the comphrehensive analysis of large rock chemical data on the relevant diagram about their characteristics, it reflects that not only the granitic rock has two different characteristics of rock series and regionalization but also shows several distinct source tendencies. Itsuggests that the large emergence of granitic rock in Archean era in the area is related to certain collision mechanism, thus resulted in the connection of the landmass, north to Hengshan and the landmass of Bupin,and so completed the cratonization of North China platform. The formation of granitic rock in early Proterozoic era is relevant to rifting which belongs to the genetic series of later orogenic to postorogenic period. 2\ The zonal super crust rock series that stretches in NEE direction on the Archaeozoic crystalline basement in Wutaishan and its vicinity area is called Wutai Group and Hutuo Group. The Wutai Group is mainly consisted of mafic volcanic rock, and uncomformably was under laid the Hutuo
基金supported by the National Natural Science Foundation of China (Nos. 91014002,40821061)Ministry of Education of China (No. B07039)
文摘Archean greenstone belts and their possible inclusion of fragments of ophiolites is an im-portant research subject, since it is correlated with the nature of early oceanic crust, and can yield in-formation on the nature of early planetary lithospheres, the origin of TTG （tonalite-trondhjemite-granodiorite） continental crust, the formation of early cratons and continents, and is related to when plate tectonics started in the Earth＇s evolutionary history. This article briefly reviews the North China craton＇s Archean ophiolite argument and proposes further studies aimed at understanding the genera- tion of greenstone belts and Archean ophiolites, and suggests some key scientific questions that remain to be answered.
