Carbon dioxide gas pools occur widely in the basins of eastern China.CO_2 gas-bearing beds are from the Teritary to Ordovician,and reservoirs are sandstone,carbonates and volcanics.The gases from these gas pools conta...Carbon dioxide gas pools occur widely in the basins of eastern China.CO_2 gas-bearing beds are from the Teritary to Ordovician,and reservoirs are sandstone,carbonates and volcanics.The gases from these gas pools contain CO_2 of 62.86 ‰ —99.55 ‰.In the Mesozoic-Cenozoic extensional basins,such as Songliao,Bohai Bay,Subei,Sanshui and Zhujingkou,the δ^(13)C_(CO_2)values of CO_2 gas pools range from-2.65‰ to-8.83‰,mainly from-3.5‰ to-6.0‰,~3He/~4He ratios are 2.65R_a to 4.96R_a.The regression equa- tion of CO_2 content and helium isotope ratio is CO_2(%)=61.3852+7.9745R/R_a,correlation coefficient r is 0.9430,CO_2 is mainly mantle-derived and magmatic origin.δ^(13)C_(CO_2)value of CO_2 gas from Well X in Yinggehai Basin is-3.80‰.~3He/~4He ratio is 0.07R_a,CO_2 is metamorphic origin.Mantle-derived and magmatic CO_2 gases are discharged from the cross areas of northeastern trending and northwestern trending faults in these Mesozoic-Cenozoic extensional basins,in the shallow level,the CO_2 gases migrate and accumulate along northeastern trending extensional faults.The activity of the Neogene to Quaternary northwestern trending tectonic-magmatism zones in eastern China is another important discharge event for mantle-derived and magmatic gases,which have great contribution to the CO_2 gas pools in this area.Metamorphic CO_2 in the Yinggehai Basin is released by the dynamic metamorphism of shear fractures.展开更多
基金the National Natural Scienoe Foundation of China
文摘Carbon dioxide gas pools occur widely in the basins of eastern China.CO_2 gas-bearing beds are from the Teritary to Ordovician,and reservoirs are sandstone,carbonates and volcanics.The gases from these gas pools contain CO_2 of 62.86 ‰ —99.55 ‰.In the Mesozoic-Cenozoic extensional basins,such as Songliao,Bohai Bay,Subei,Sanshui and Zhujingkou,the δ^(13)C_(CO_2)values of CO_2 gas pools range from-2.65‰ to-8.83‰,mainly from-3.5‰ to-6.0‰,~3He/~4He ratios are 2.65R_a to 4.96R_a.The regression equa- tion of CO_2 content and helium isotope ratio is CO_2(%)=61.3852+7.9745R/R_a,correlation coefficient r is 0.9430,CO_2 is mainly mantle-derived and magmatic origin.δ^(13)C_(CO_2)value of CO_2 gas from Well X in Yinggehai Basin is-3.80‰.~3He/~4He ratio is 0.07R_a,CO_2 is metamorphic origin.Mantle-derived and magmatic CO_2 gases are discharged from the cross areas of northeastern trending and northwestern trending faults in these Mesozoic-Cenozoic extensional basins,in the shallow level,the CO_2 gases migrate and accumulate along northeastern trending extensional faults.The activity of the Neogene to Quaternary northwestern trending tectonic-magmatism zones in eastern China is another important discharge event for mantle-derived and magmatic gases,which have great contribution to the CO_2 gas pools in this area.Metamorphic CO_2 in the Yinggehai Basin is released by the dynamic metamorphism of shear fractures.
