Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusio...Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusions,of which most of them are CO2-bearing inclusions. The fluid salinity is 1. 43%- 9. 08%,mainly concentrated in the range of 4. 69%- 5. 41%,the density of CO2 is 0. 69- 0. 80 g / cm3,indicating that the mineralization fluid is low-medium salinity and low density fluid. A series of studies on gold-bearing quartz vein and fluid inclusions show that there exists a positive correlation between the degree of the gold mi-neralization and the amount of CO2 in the inclusions,which means the more CO2-bearing inclusions there are,the higher the content of gold is. CO2 is mainly derived from mantle fluid,and the ore-forming fluid should be derived from mantle fluid and the crust shallow fluid. The conclusions have important denotative meaning on the metallogenic mechanism of orogenic gold deposit and the deep prospecting on metal deposit.展开更多
The southeast depression of Qinnan Sag is a potential oil-gas exploration region in the Bohai Sea area. With the analysis of large quantity of rock thin sections,scanning electron microscope and the physical property ...The southeast depression of Qinnan Sag is a potential oil-gas exploration region in the Bohai Sea area. With the analysis of large quantity of rock thin sections,scanning electron microscope and the physical property data of reservoir,the authors studied the petrological characteristics and the evolution of pore and fluid of sandstone in the deeper strata in 29-2 structure in Qinhuangdao area. The results show that the evolutionary tendency of Paleogene sandstone reservoir porous fluid in research area is changed from alkaline porous fluid to acidic porous fluid,and back to alkaline porous fluid. There are three stages of reservoir porous evolution in Qinhuangdao area,namely sharp decrease in porosity due to mechanical compaction,increase in porosity because of corrosion and dissolution,and remarkable reduction owing to carbonate cementation.展开更多
In order to further understand the ore characteristics and metallogenic age of Yuanjiacun iron deposit in Shanxi, the mineral composition characteristics of iron ore were studied on the basis of field investigation an...In order to further understand the ore characteristics and metallogenic age of Yuanjiacun iron deposit in Shanxi, the mineral composition characteristics of iron ore were studied on the basis of field investigation and microscopic observation. Magnetite, hematite, goethite and pyrite of different stages were identified according to their texture and structure features. Two sets of ^(207)Pb/^(206)Pb ages have been obtained by ICPMS isotope dating of magnetite quartzite, of which the zircon age with metamorphic origin is 1 916±88 Ma, representing the main metamorphic age of iron deposit. Another group of magmatic zircons with rhythmic zones are of 2 280±30 Ma age, representing the diagenetic age of iron formation. In addition, scattered age records after metamorphism indicate frequent hydrothermal events after mineralization. Based on the mineral fabric characteristics and the age data of zircons of different origins, it is known that the deposit has undergone sedimentary mineralization period, metamorphic mineralization period, hydrothermal mineralization period and weathering mineralization period.展开更多
基金Supported by Project of National Natural Science Foundation of China(No.41172072)
文摘Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusions,of which most of them are CO2-bearing inclusions. The fluid salinity is 1. 43%- 9. 08%,mainly concentrated in the range of 4. 69%- 5. 41%,the density of CO2 is 0. 69- 0. 80 g / cm3,indicating that the mineralization fluid is low-medium salinity and low density fluid. A series of studies on gold-bearing quartz vein and fluid inclusions show that there exists a positive correlation between the degree of the gold mi-neralization and the amount of CO2 in the inclusions,which means the more CO2-bearing inclusions there are,the higher the content of gold is. CO2 is mainly derived from mantle fluid,and the ore-forming fluid should be derived from mantle fluid and the crust shallow fluid. The conclusions have important denotative meaning on the metallogenic mechanism of orogenic gold deposit and the deep prospecting on metal deposit.
基金Supported by Project of Tianjin Branch of CNOOC Ltd.(CCL2012TJXSBS0282)Project of CNOOC Ltd.,Research Center of Beijing(CCL2015RCPS0150RCN)Project of Institute of Mineral Resources,Chinese Academy of Geological Sciences,China Geological Survey(DD20160344)
文摘The southeast depression of Qinnan Sag is a potential oil-gas exploration region in the Bohai Sea area. With the analysis of large quantity of rock thin sections,scanning electron microscope and the physical property data of reservoir,the authors studied the petrological characteristics and the evolution of pore and fluid of sandstone in the deeper strata in 29-2 structure in Qinhuangdao area. The results show that the evolutionary tendency of Paleogene sandstone reservoir porous fluid in research area is changed from alkaline porous fluid to acidic porous fluid,and back to alkaline porous fluid. There are three stages of reservoir porous evolution in Qinhuangdao area,namely sharp decrease in porosity due to mechanical compaction,increase in porosity because of corrosion and dissolution,and remarkable reduction owing to carbonate cementation.
基金Supported by Project of Compilation and Renewal of National Marine and Land Metallogenic Maps(3S2170804422)
文摘In order to further understand the ore characteristics and metallogenic age of Yuanjiacun iron deposit in Shanxi, the mineral composition characteristics of iron ore were studied on the basis of field investigation and microscopic observation. Magnetite, hematite, goethite and pyrite of different stages were identified according to their texture and structure features. Two sets of ^(207)Pb/^(206)Pb ages have been obtained by ICPMS isotope dating of magnetite quartzite, of which the zircon age with metamorphic origin is 1 916±88 Ma, representing the main metamorphic age of iron deposit. Another group of magmatic zircons with rhythmic zones are of 2 280±30 Ma age, representing the diagenetic age of iron formation. In addition, scattered age records after metamorphism indicate frequent hydrothermal events after mineralization. Based on the mineral fabric characteristics and the age data of zircons of different origins, it is known that the deposit has undergone sedimentary mineralization period, metamorphic mineralization period, hydrothermal mineralization period and weathering mineralization period.
