The oxidation state(expressed as the oxygen fugacity,fO_(2))plays important roles in many important chemical and physical processes of the lithospheric mantle.These include magma genesis,generation and speciation of v...The oxidation state(expressed as the oxygen fugacity,fO_(2))plays important roles in many important chemical and physical processes of the lithospheric mantle.These include magma genesis,generation and speciation of volatiles,metasomatism,as well as determining the stability field of mineral assemblages,including formation or transformation of diamond/graphite.The fO_(2)can be determined by the oxybarometers calibrated based on thermodynamic equilibria among the(nominal)O_(2)and minerals which have one or several multivalent elements(e.g.,Fe,V,Eu,Ni,Ru,Ce,Cr,etc.).Because iron is richer than minor/trace elements in mantle minerals,oxybarometers calibrated based on the ferric iron contents of spinel(for spinel-facies mantle xenoliths)or garnet(for garnet-facies mantle xenoliths)are the most typically calibrated and applied.展开更多
基金supported by the National Natural Science Foundation of China(42330303 and 42302055)the National Science and Technology Major Project(2025ZD1005304).
文摘The oxidation state(expressed as the oxygen fugacity,fO_(2))plays important roles in many important chemical and physical processes of the lithospheric mantle.These include magma genesis,generation and speciation of volatiles,metasomatism,as well as determining the stability field of mineral assemblages,including formation or transformation of diamond/graphite.The fO_(2)can be determined by the oxybarometers calibrated based on thermodynamic equilibria among the(nominal)O_(2)and minerals which have one or several multivalent elements(e.g.,Fe,V,Eu,Ni,Ru,Ce,Cr,etc.).Because iron is richer than minor/trace elements in mantle minerals,oxybarometers calibrated based on the ferric iron contents of spinel(for spinel-facies mantle xenoliths)or garnet(for garnet-facies mantle xenoliths)are the most typically calibrated and applied.
