High-Mg andesites(HMAs)typically originate in subduction-related tectonic settings,including active continental margins and island arcs,and studies of HMAs can constrain the tectonic evolution of the South China Block...High-Mg andesites(HMAs)typically originate in subduction-related tectonic settings,including active continental margins and island arcs,and studies of HMAs can constrain the tectonic evolution of the South China Block and Paleo-Tethyan Ocean.This paper presents new chronological and geochemical data for high-Mg gabbroic diorites in the Funing area,southern South China.The gabbroic diorites yield ages of 254-249 Ma,and have moderate SiO2 contents(51.3%-57.8%),high MgO contents(4.6%-10.2%)and Mg^(#)values(52-75),enrichment in large-ion lithophile elements and light rare earth elements,and depletion in high-field-strength elements-collectively displaying geochemical signatures typical of sanukites.The gabbroic diorites have radiogenic initial Sr and Pb isotopic compositions,and negativeεNd(t)andεHf(t)values.These characteristics distinguish the Funing gabbroic diorites from subduction-related igneous rocks in the Paleo-Pacific tectonic domain.Instead,they are isotopically similar to HMAs and basalts along the Paleo-Tethys suture.We propose the high-Mg gabbroic diorites and basaltic andesites in Funing area share a common mantle source,linked to subduction and rollback of the Paleo-Tethyan plate beneath the South China Block,which triggered back-arc rifting and partial melting of the metasomatized lithospheric mantle during the Late Permian to Early Triassic.展开更多
Taking the shale of the second member of the Paleogene Funing Formation in the Qintong Sag,Subei Basin,China,as an example,this study integrates methods such as rock section imaging,optical and electron microscopy,mic...Taking the shale of the second member of the Paleogene Funing Formation in the Qintong Sag,Subei Basin,China,as an example,this study integrates methods such as rock section imaging,optical and electron microscopy,micro-area mineral analysis and laser confocal in-situ observation,assisted by Wood’s alloy impregnation and other auxiliary techniques,to systematically investigate lamina types and combinations,pore-fracture units and fracture systems,hydrocarbon occurrence and shale oil enrichment patterns.The following results are obtained.(1)Three basic lamina types,i.e.felsic,clay-rich,and carbonate,are identified in the study area.Their combinations are controlled by the interplay of climate,hydrodynamics,and tectonics,with vertical distribution influenced by lake-level fluctuations and event sedimentation.(2)Reservoir space is controlled by lithological composition,predominantly comprising intergranular pores and fractures within felsic laminae and intercrystalline pores and fractures within clay-rich laminae,which together with dissolution pores and organic matter pores form a matrix pore-fracture system.This system,combined with bedding fractures,structural fractures,and overpressure fractures,constitutes a hierarchical and three-dimensional transport network.(3)The“felsic+clay-rich+organic-rich”lamina combination exhibits an optimal pore-fracture configuration,serving as the preferred shale oil reservoir unit,continuously distributed in sub-members Ⅰ-Ⅱ.(4)A“hierarchical migration-dynamic sealing”in-source enrichment model is established.Specifically,hydrocarbon generation in clay-rich laminae creates overpressure,driving migration through nanoscale pore-fracture networks and forming localized accumulations;subsequent fracture formation from overpressure breaches lamina interfaces,allowing hydrocarbons to migrate under capillary pressure into micrometer-scale porous domains in felsic laminae;structural fractures connect multiple laminae to form a 3D seepage system,while cementation zones associated with micro-faults and lamina interfaces create dynamic sealing.Ultimately,shale oil accumulates in source via the coupling of pores,fractures and laminae.展开更多
The research on the correlation between hydrocarbon accumulations and magmatic activities has always attracted aroused much wide attention.Existing research has primarily the hydrocarbon generations capability of sour...The research on the correlation between hydrocarbon accumulations and magmatic activities has always attracted aroused much wide attention.Existing research has primarily the hydrocarbon generations capability of source rocks and the quality of reservoirs by diabase intrusions.whereas,rare systematic research has been conducted on the oiliness and enrichment mechanism.To be specific,the diabase intrusive zone,the contact metamorphic zone and the normal shale zone of the Funing Formation in the Gaoyou Sag,Subei Basin were taken as the object of this study.Moreover,in this study,the hydrocarbon generation quality,reservoir quality,and oil-bearing quality of diabase-metamorphic zone-normal shale were evaluated using X-ray diffractions,argon ion polishing-field emission scanning electron microscope,energy spectrum,rock slice/light-sheet microscopic observations,organic geochemical tests,N_(2) gas adsorption and 2D NMR tests.The results indicated that the intrusive zone,the metamorphic zone,and the normal zone were formed in order by the degree of effect of diabase intrusions.Secondly,the oil content of different parts exhibited significant heterogeneity due to the baking effect of diabase,and the metamorphic zone had the significantly better oil-bearing nature than the intrusive zone.Lastly,a distribution model was proposed for the diabase intrusive zone-metamorphic zone-normal surrounding rock zone.展开更多
The company covers separation with whole lines of light, medium and heavy rare earths, with annual separation volume of rare earth oxides of 4,500 tons. It also produces rare earth oxides, fluorides and salts. Product...The company covers separation with whole lines of light, medium and heavy rare earths, with annual separation volume of rare earth oxides of 4,500 tons. It also produces rare earth oxides, fluorides and salts. Products with high-purity and super-high-purity are produced according to customer's request. Under the technological guidance of domestic experts and application of modern展开更多
The occurrence characteristics of shale oil are of great significance to the movability of shale oil.In this study,the occurrence characteristics of oil in the shale matrix at Funing Formation shale in Subei Basin wer...The occurrence characteristics of shale oil are of great significance to the movability of shale oil.In this study,the occurrence characteristics of oil in the shale matrix at Funing Formation shale in Subei Basin were quantitatively evaluated by organic geochemistry and microscopic pore structure characterization experiments.The Multiple Isothermal Stages Pyrolysis(MIS)experiment results show that the content of total oil,adsorbed oil,and free oil in the shales are 3.15-11.25 mg/g,1.41-4.95 mg/g,and 1.74-6.51 mg/g,respectively.among which the silicon-rich shale has the best oil-bearing.The relative content of free oil shows an increasing trend in pores with pore diameters greater than 3 nm.When the relative content of free oil reaches 100%,the pore size of silicon-rich shale is about 200 nm,while that of calcium-rich shale,clay-rich shale,and siliceous mixed shale is about 10 nm.The occurrence law of adsorbed oil is opposite to that of free oil,which indicates that shale oil will occur in the pores and fractures in a free state in a more extensive pore size range(>200 nm).This study also enables us to further understand the occurrence characteristics of shale oil under the interaction of occurrence state and occurrence space.展开更多
基金supported by the National Natural Science Foundation of China (42473063)Guike AD24010023, the Seventh Guangxi Zhuang Autonomous Region Bagui Scholars Program (to LIU Xijun)the Guangxi Natural Science Foundations of China (2025GXNSFBA069054)
文摘High-Mg andesites(HMAs)typically originate in subduction-related tectonic settings,including active continental margins and island arcs,and studies of HMAs can constrain the tectonic evolution of the South China Block and Paleo-Tethyan Ocean.This paper presents new chronological and geochemical data for high-Mg gabbroic diorites in the Funing area,southern South China.The gabbroic diorites yield ages of 254-249 Ma,and have moderate SiO2 contents(51.3%-57.8%),high MgO contents(4.6%-10.2%)and Mg^(#)values(52-75),enrichment in large-ion lithophile elements and light rare earth elements,and depletion in high-field-strength elements-collectively displaying geochemical signatures typical of sanukites.The gabbroic diorites have radiogenic initial Sr and Pb isotopic compositions,and negativeεNd(t)andεHf(t)values.These characteristics distinguish the Funing gabbroic diorites from subduction-related igneous rocks in the Paleo-Pacific tectonic domain.Instead,they are isotopically similar to HMAs and basalts along the Paleo-Tethys suture.We propose the high-Mg gabbroic diorites and basaltic andesites in Funing area share a common mantle source,linked to subduction and rollback of the Paleo-Tethyan plate beneath the South China Block,which triggered back-arc rifting and partial melting of the metasomatized lithospheric mantle during the Late Permian to Early Triassic.
基金Supported by the National Natural Science Foundation of China(U24B6002)Project of the Technology Department of China Petroleum&Chemical Corporation(P24117,P23190).
文摘Taking the shale of the second member of the Paleogene Funing Formation in the Qintong Sag,Subei Basin,China,as an example,this study integrates methods such as rock section imaging,optical and electron microscopy,micro-area mineral analysis and laser confocal in-situ observation,assisted by Wood’s alloy impregnation and other auxiliary techniques,to systematically investigate lamina types and combinations,pore-fracture units and fracture systems,hydrocarbon occurrence and shale oil enrichment patterns.The following results are obtained.(1)Three basic lamina types,i.e.felsic,clay-rich,and carbonate,are identified in the study area.Their combinations are controlled by the interplay of climate,hydrodynamics,and tectonics,with vertical distribution influenced by lake-level fluctuations and event sedimentation.(2)Reservoir space is controlled by lithological composition,predominantly comprising intergranular pores and fractures within felsic laminae and intercrystalline pores and fractures within clay-rich laminae,which together with dissolution pores and organic matter pores form a matrix pore-fracture system.This system,combined with bedding fractures,structural fractures,and overpressure fractures,constitutes a hierarchical and three-dimensional transport network.(3)The“felsic+clay-rich+organic-rich”lamina combination exhibits an optimal pore-fracture configuration,serving as the preferred shale oil reservoir unit,continuously distributed in sub-members Ⅰ-Ⅱ.(4)A“hierarchical migration-dynamic sealing”in-source enrichment model is established.Specifically,hydrocarbon generation in clay-rich laminae creates overpressure,driving migration through nanoscale pore-fracture networks and forming localized accumulations;subsequent fracture formation from overpressure breaches lamina interfaces,allowing hydrocarbons to migrate under capillary pressure into micrometer-scale porous domains in felsic laminae;structural fractures connect multiple laminae to form a 3D seepage system,while cementation zones associated with micro-faults and lamina interfaces create dynamic sealing.Ultimately,shale oil accumulates in source via the coupling of pores,fractures and laminae.
基金financially supported by the National Natural Science Foundation of China(Grant No.42072150).
文摘The research on the correlation between hydrocarbon accumulations and magmatic activities has always attracted aroused much wide attention.Existing research has primarily the hydrocarbon generations capability of source rocks and the quality of reservoirs by diabase intrusions.whereas,rare systematic research has been conducted on the oiliness and enrichment mechanism.To be specific,the diabase intrusive zone,the contact metamorphic zone and the normal shale zone of the Funing Formation in the Gaoyou Sag,Subei Basin were taken as the object of this study.Moreover,in this study,the hydrocarbon generation quality,reservoir quality,and oil-bearing quality of diabase-metamorphic zone-normal shale were evaluated using X-ray diffractions,argon ion polishing-field emission scanning electron microscope,energy spectrum,rock slice/light-sheet microscopic observations,organic geochemical tests,N_(2) gas adsorption and 2D NMR tests.The results indicated that the intrusive zone,the metamorphic zone,and the normal zone were formed in order by the degree of effect of diabase intrusions.Secondly,the oil content of different parts exhibited significant heterogeneity due to the baking effect of diabase,and the metamorphic zone had the significantly better oil-bearing nature than the intrusive zone.Lastly,a distribution model was proposed for the diabase intrusive zone-metamorphic zone-normal surrounding rock zone.
文摘The company covers separation with whole lines of light, medium and heavy rare earths, with annual separation volume of rare earth oxides of 4,500 tons. It also produces rare earth oxides, fluorides and salts. Products with high-purity and super-high-purity are produced according to customer's request. Under the technological guidance of domestic experts and application of modern
基金This work was financially supported by the National Natural Science Foundation of China(41972123,41922015)the Natural Science Foundation of Shandong Province(ZR2020QD036).
文摘The occurrence characteristics of shale oil are of great significance to the movability of shale oil.In this study,the occurrence characteristics of oil in the shale matrix at Funing Formation shale in Subei Basin were quantitatively evaluated by organic geochemistry and microscopic pore structure characterization experiments.The Multiple Isothermal Stages Pyrolysis(MIS)experiment results show that the content of total oil,adsorbed oil,and free oil in the shales are 3.15-11.25 mg/g,1.41-4.95 mg/g,and 1.74-6.51 mg/g,respectively.among which the silicon-rich shale has the best oil-bearing.The relative content of free oil shows an increasing trend in pores with pore diameters greater than 3 nm.When the relative content of free oil reaches 100%,the pore size of silicon-rich shale is about 200 nm,while that of calcium-rich shale,clay-rich shale,and siliceous mixed shale is about 10 nm.The occurrence law of adsorbed oil is opposite to that of free oil,which indicates that shale oil will occur in the pores and fractures in a free state in a more extensive pore size range(>200 nm).This study also enables us to further understand the occurrence characteristics of shale oil under the interaction of occurrence state and occurrence space.
