Geo-Marine Letters

, Volume 17, Issue 2, pp 169–174

13C isotope depletion in ikaite crystals: evidence for methane release from the Siberian shelves ?

  • C. J. Schubert
  • D. Nürnberg
  • N. Scheele
  • F. Pauer
  • M. Kriews

DOI: 10.1007/s003670050023

Cite this article as:
Schubert, C., Nürnberg, D., Scheele, N. et al. Geo-Marine Letters (1997) 17: 169. doi:10.1007/s003670050023

Abstract

 Ikaite crystals (CaCO3×6H2O) have been found at 232- to 238-cm sediment depth in R/V Polarstern core PS2460-4 from the Laptev Sea continental margin in a water depth of 204 m. δ13C values of this phase average −36.3±0.4‰ PDB (N=2), which is significantly outside the range of normal marine carbonates. The CO2 involved in the precipitation of the ikaite is most probably derived from methane, which has extremely depleted 13C isotope values. Two possible sources of methane in these sediments are: (1) methanogenesis (decomposition of organic matter under anaerobic conditions); and (2) gas hydrates, which are known to occur in the Siberian shelf regions.

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • C. J. Schubert
    • 1
  • D. Nürnberg
    • 1
  • N. Scheele
    • 1
  • F. Pauer
    • 1
  • M. Kriews
    • 1
  1. 1.Alfred Wegener Institute for Polar and Marine Research, Columbusstrasse, 27568 Bremerhaven, GermanyDE