Natural gas,consisting primarily of methane(CH_(4)),has become a major source of clean energy in modern society in many parts of the globe.Recent experimental observations and discoveries of deep-sourced abiotic CH_(4...Natural gas,consisting primarily of methane(CH_(4)),has become a major source of clean energy in modern society in many parts of the globe.Recent experimental observations and discoveries of deep-sourced abiotic CH_(4)in cold subduction zones indicate the important ability of cold subducted slabs to generate natural gas reservoirs.However,most CH_(4)flux and reservoirs remain unknown and their potential is overlooked in global carbon flux estimations.Massive abiotic CH_(4)-rich fluid inclusions(FIs)in garnet and omphacite from ultrahigh-pressure(UHP)eclogites have been found in the Western Tianshan(WT)UHP metamorphic belt,which provides one ideal case for quantification of abiotic CH_(4)stored in the cold subducted crust.By two methods,we assess the abiotic CH_(4)content stored in the Chinese WT HP–UHP metamorphic belt.Our calculations show that at least 113 Mt CH_(4)is stored in the WT eclogites.We also discuss the implications for CH_(4)reservoirs in subduction zones worldwide and speculate that the cold subduction zones may represent one of the largest,yet overlooked,sources of abiotic CH_(4)on Earth,which should not be ignored in the global natural resource and carbon flux estimations.展开更多
基金financially supported by the National Key Research and Development Program of China(Grant No.2019YFA0708501)the National Natural Science Foundation of China(Grant No.42172060)。
文摘Natural gas,consisting primarily of methane(CH_(4)),has become a major source of clean energy in modern society in many parts of the globe.Recent experimental observations and discoveries of deep-sourced abiotic CH_(4)in cold subduction zones indicate the important ability of cold subducted slabs to generate natural gas reservoirs.However,most CH_(4)flux and reservoirs remain unknown and their potential is overlooked in global carbon flux estimations.Massive abiotic CH_(4)-rich fluid inclusions(FIs)in garnet and omphacite from ultrahigh-pressure(UHP)eclogites have been found in the Western Tianshan(WT)UHP metamorphic belt,which provides one ideal case for quantification of abiotic CH_(4)stored in the cold subducted crust.By two methods,we assess the abiotic CH_(4)content stored in the Chinese WT HP–UHP metamorphic belt.Our calculations show that at least 113 Mt CH_(4)is stored in the WT eclogites.We also discuss the implications for CH_(4)reservoirs in subduction zones worldwide and speculate that the cold subduction zones may represent one of the largest,yet overlooked,sources of abiotic CH_(4)on Earth,which should not be ignored in the global natural resource and carbon flux estimations.
