Startseite
English
Erweiterte Suche
Durchblättern nach ...
Publikationen im Überblick
Ansprechpartner
Hilfe
DOI
 |
|
Open Access Green möglich sobald Postprint bei der ZB eingereicht worden ist.
Stable isotope disequilibria in travertine from high pH waters: Laboratory investigations and field observations from Oman.
Geochim. Cosmochim. Acta 56, 2041-2050 (1992)
Ultramafic rocks in northern Oman host unusual, hyperalkaline groundwaters (pH > 11.5) which precipitate inorganic travertine by diffusive uptake of atmospheric CO2 after discharge. Stable isotope fractionation during CO2 uptake results in strong depletions of the carbonate phase (δ13C values as low as -27.5‰ and δ18O values of -16.9‰ PDB). Experiments under closed and open system conditions show that a kinetic depletion in the order of 15.5‰ for 13C occurs during hydroxylation of aqueous CO2 (CO2(aq) + OH- reaction), attributed to a lower activation energy for 12C-O vs 13C-O. The observed 18O depletion can be accounted for by CO2 reaction with OH- (ε{lunate}18OOH--H2O ≅ -40‰) without subsequent exchange and with no evidence of significant additional kinetic effects. Calculated reaction rates show hydroxylation to be the rate limiting step and that CO2(g)-CO2(aq) exchange at the gas/solution interface achieves isotopic equilibrium.
Altmetric
Weitere Metriken?
Zusatzinfos bearbeiten
[➜Einloggen]
Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
ISSN (print) / ISBN
0016-7037
e-ISSN
1872-9533
Zeitschrift
Geochimica et Cosmochimica Acta
Quellenangaben
Band: 56,
Heft: 5,
Seiten: 2041-2050
Verlag
Elsevier
Nichtpatentliteratur
Publikationen
Begutachtungsstatus
Peer reviewed
Institut(e)
Institut für Hydrologie