The Hongtoushan Volcanogenic Massive Sulphide Deposit（VMSD）occurs in the Hunbei granite-greenstone terrane,Liaoning Province,NE China.Rocks in the mining area have been metamorphosed around 3.0-2.8 Ga to upper amphi...The Hongtoushan Volcanogenic Massive Sulphide Deposit（VMSD）occurs in the Hunbei granite-greenstone terrane,Liaoning Province,NE China.Rocks in the mining area have been metamorphosed around 3.0-2.8 Ga to upper amphibolite facies at temperatures between 600℃and 650℃.Cordierite-anthophyllite gneiss（CAG）in the Hongtoushan mining area,which occurs hundreds of meters below the ore horizon,corresponds to the metamorphosed semi-conformable alteration zone of the VMSD hydrothermal system,whereas the one immediately below the main ore layer represents the metamorphosed pipe-like alteration zone.Whole-rock oxygen isotope signatures were well preserved in both types of CAGs,although the mineral components have been entirely changed during regional metamorphism.Therefore,whole-rock oxygen isotopes can be used to estimate the formation temperature of both types of alteration zone.Calculations show that the semi-conformable and pipelike alteration zones for the Hongtoushan submarine hydrothermal system were formed at 290-360℃and 285-320°C,respectively,whereas estimates for the former were slightly higher than that of the latter,indicating that the semi-conformable alteration zone represents the deep part of the Hongtoushan seafloor hydrothermal system,while the pipe-like alteration zone represents the discharge conduits for metal-rich fluids,which is closer to the seafloor.展开更多
1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Tr...1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Triangle Area展开更多
The main scope of this research is to detect geologic structure trends affecting the study area, determine uranium anomalous areas and define alteration zones. Airborne magnetic data were used to detect the geologic s...The main scope of this research is to detect geologic structure trends affecting the study area, determine uranium anomalous areas and define alteration zones. Airborne magnetic data were used to detect the geologic structure trends affecting the study area through applying edge detectors such as total horizontal derivative, analytic signal and tilt derivative. The radio-spectrometry data and Landsat image data were used in determining the uranium anomalous areas and alteration zones. The integration between geology, magnetic and Landsat image was applied through constructing lineaments density map for the three data sets resulting in the leading of NW-SE trend all over the area. This integration makes clear that the basement (Red Sea hills), Esh El-mallaha range and G. Zeit are limiting two large basins (West Mallaha and Zeit). In addition, the main areas of uranium enrichment (Duwi formation at Esh El-Mallaha range) are found to be well related to alteration zones.展开更多
基金supported financially by the National Basic Research Program of the People's Republic of China (2006CB403501)the National Natural Science Foundation of China(Nos 40872050,40872064)
文摘The Hongtoushan Volcanogenic Massive Sulphide Deposit（VMSD）occurs in the Hunbei granite-greenstone terrane,Liaoning Province,NE China.Rocks in the mining area have been metamorphosed around 3.0-2.8 Ga to upper amphibolite facies at temperatures between 600℃and 650℃.Cordierite-anthophyllite gneiss（CAG）in the Hongtoushan mining area,which occurs hundreds of meters below the ore horizon,corresponds to the metamorphosed semi-conformable alteration zone of the VMSD hydrothermal system,whereas the one immediately below the main ore layer represents the metamorphosed pipe-like alteration zone.Whole-rock oxygen isotope signatures were well preserved in both types of CAGs,although the mineral components have been entirely changed during regional metamorphism.Therefore,whole-rock oxygen isotopes can be used to estimate the formation temperature of both types of alteration zone.Calculations show that the semi-conformable and pipelike alteration zones for the Hongtoushan submarine hydrothermal system were formed at 290-360℃and 285-320°C,respectively,whereas estimates for the former were slightly higher than that of the latter,indicating that the semi-conformable alteration zone represents the deep part of the Hongtoushan seafloor hydrothermal system,while the pipe-like alteration zone represents the discharge conduits for metal-rich fluids,which is closer to the seafloor.
基金supported by the Funds for the program of the National Natural Science Foundation (Noes. 41572060, U1133602)Projects of YM Lab (2011)Innovation Team of Yunnan province and KMUST (2008,2012)
文摘1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Triangle Area
文摘The main scope of this research is to detect geologic structure trends affecting the study area, determine uranium anomalous areas and define alteration zones. Airborne magnetic data were used to detect the geologic structure trends affecting the study area through applying edge detectors such as total horizontal derivative, analytic signal and tilt derivative. The radio-spectrometry data and Landsat image data were used in determining the uranium anomalous areas and alteration zones. The integration between geology, magnetic and Landsat image was applied through constructing lineaments density map for the three data sets resulting in the leading of NW-SE trend all over the area. This integration makes clear that the basement (Red Sea hills), Esh El-mallaha range and G. Zeit are limiting two large basins (West Mallaha and Zeit). In addition, the main areas of uranium enrichment (Duwi formation at Esh El-Mallaha range) are found to be well related to alteration zones.
