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Carbon and hydrogen isotope constraints on degassing of CO 2 and H 2 O in submarine lavas from the Pitcairn hotspot (South Pacific)
Author(s) -
Aubaud Cyril,
Pineau Françoise,
Hékinian Roger,
Javoy Marc
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl024907
Subject(s) - hotspot (geology) , geology , basalt , isotopic signature , mantle (geology) , volcano , isotopes of carbon , isotope , submarine , geochemistry , hydrogen , mineralogy , earth science , oceanography , environmental chemistry , total organic carbon , chemistry , seismology , physics , organic chemistry , quantum mechanics
The analysis of CO 2 –δ 13 C–H 2 O–δD in vesicles of 35 submarine volcanic glasses reveals that open‐system degassing, following closed‐system degassing, is responsible for the observed variations in volatile concentration and isotopic ratios. The least degassed samples allow the assessment of minimum estimates for the flux of CO 2 and H 2 O from the Pitcairn hotspot: 2.24 ± 0.17 10 4 tons C yr −1 and 1.32 ± 0.82 10 5 tons H 2 O yr −1 . The results also suggest that the carbon in the source of the Pitcairn hotspot may have a δ 13 C value around −6‰, 2‰ lower than the source of mid‐ocean ridge basalts. This indicates either a possible contribution from the lower mantle or the possible involvement of decarbonated recycled materials with an unusual carbon isotopic signature.