@article{fdi:010083212,
  title = {{T}he chemistry of hyperalkaline springs in serpentinizing environments : 1. {T}he composition of free gases in {N}ew {C}aledonia compared to other springs worldwide},
  author = {{M}onnin, {C}. and {Q}u{\'e}m{\'e}neur, {M}arianne and {P}rice, {R}. and {J}eanpert, {J}. and {M}aurizot, {P}. and {B}oulart, {C}. and {D}onval, {J}. {P}. and {P}elletier, {B}ernard},
  editor = {},
  language = {{ENG}},
  abstract = {{S}erpentinization is a natural process that transforms ferromagnesian minerals such as olivine into serpentine and that produces waters at very high p{H} and gases enriched in methane ({CH}4) and hydrogen ({H}-2). {W}e report the composition of gases venting at two springs ({B}ain des {J}aponais and {R}iviere des {K}aoris) of the serpentinizing environment of the {P}rony {B}ay ({N}ew {C}aledonia) collected eight times between 2011 and 2014, along with in situ measurements (temperature, p{H}, oxydo-reduction potential, dissolved oxygen content) of on-land alkaline springs of the {S}outhern {N}ew {C}aledonia ophiolite. {V}enting gases are mainly composed of {H}-2, {CH}4, and {N}-2 and their composition has slightly varied during the 4-year field survey. {A}n elevated oxygen ({O}-2) content in a high-p{H} water sample is due to air uptake during surface flow. {O}-2-corrected gas compositions along with those published for gas data obtained at similar serpentinizing environments ({I}taly, {T}urkey, {P}hilippines, and {O}man) show that the {H}-2 and {CH}4 concentrations display a linear correlation with a slope close to the value corresponding to the {CH}4 production from carbon dioxide rather from a less oxidized carbon such as carbon monoxide. {A}lthough these data are consistent with the stoichiometry of the {S}abatier reaction, as such in the gas phase, it is also possible that microbial hydrogenotrophic methanogenesis takes place in the aqueous phase followed by degassing. {A} diagram is proposed that outlines the partitioning of {H}-2 and {CH}4 between the gaseous and aqueous phases and the need to consider a two-phase flow in the hydrology of these hyperalkaline environments.},
  keywords = {serpentinization ; methane ; hydrogen ; {N}ew {C}aledonia ; {S}abatier reaction ; {P}rony {B}ay ; {NOUVELLE} {CALEDONIE} ; {PRONY} {BAIE}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {B}iogeosciences},
  volume = {126},
  numero = {9},
  pages = {e2021{JG}006243 [17 ]},
  ISSN = {2169-8953},
  year = {2021},
  DOI = {10.1029/2021jg006243},
  URL = {https://www.documentation.ird.fr/hor/fdi:010083212},
}