Abstract:The volatiles in mantle xenoliths can provide the clues of mantle evolution and are used to reveal the nature and origin of recycled crustal volatiles (RCVs) in Earth’s mantle. The carbon, oxygen and hydrogen isotopic compositions of volatiles in olivine (Olv), orthopyroxene (Opx) and clinopyroxene (Cpx) of lherzolite xenoliths from eastern China have been measured by stepwise heating mass spectrometers. The results integrated with chemical composition of volatiles (Zhang et al., 2004) show that the volatiles resided in early-stage fluid inclusions and structural defects and vacancies have been mainly released at high temperature (800-1200°C), and display lighter δ13C values of CO2 and CO, which is distinct from mantle xenoliths in other places of the world. The volatiles trapped in late-stage fluid inclusions have been released at low temperature (300-600°C). The RCVs with different potential origins have been identified in three types of volatiles of mantle minerals in the subcontinental lithospheric mantle according to mantle evolution events beneath eastern China and mineral properties: (1) Initial volatiles of lithospheric mantle are released at 800-1200°C from Olv etc. refractory minerals, and show significant difference in chemical compositions between in Northern China craton (NCC, dominated by CO) and in Southern China craton (SCC, dominated by CO2), which represent the volatiles trapped in distinct development stage of NCC and SCC prior to their combination. They are characterized by δDH2, H2O, δ13CCH4 and δ18OCO2 of mantle origin with lighter δ13C values of CO2 and CO, suggested that a little of RCVs mixed into initial volatiles of old craton continental mantle during Proterozoic continental collision (1.9Ga). (2) The volatiles in mantle metasomatism are released at 800-1200°C from Opx and Cpx and dominated by H2, H2 contents in NCC (80.73 mm3.STP/g) are significantly lower than in SCC (138.91 mm3.STP/g). δDH2 and δ13CCH4 with mantle characteristics implied that the main part of metasomatic volatiles are derived from mantle, lighter δ13C values of CO2 and CO, heavier δ18O of CO2 suggested that a recycled crustal fluid with terrigenous features have been involved possibly by a crust-mantle interaction during Mesozoic combination process of NCC and SCC. (3) The volatiles of subcontinental lithosphere thinning are released at 400-600°C from Olv, Opx and Cpx of mantle xenoliths, and composed mainly of CO2 with no significant difference between in NCC and in SCC, suggested a common development condition between NCC and SCC. They are characterized by crustal δ13C of CO2 and CO, biogenic δ13C of CH4, lighter and variable δ18O of CO2, and lighter δD of H2, suggested a recycled oceanic crustal volatile which could be derived from dehydration of the subducted paleo-Pacific lithosphere (or predecessor) that lies horizontally in the transition zone beneath eastern China.