Cold-seep-driven carbonate deposits at the Central American forearc: contrasting evolution and timing in escarpment and mound settings

Liebetrau, Volker, Augustin, Nico, Kutterolf, Steffen, Schmidt, Mark, Eisenhauer, Anton, Garbe-Schönberg, Dieter and Weinrebe, Wilhelm (2014) Cold-seep-driven carbonate deposits at the Central American forearc: contrasting evolution and timing in escarpment and mound settings International Journal of Earth Sciences, 103 (7). pp. 1845-1872. DOI 10.1007/s00531-014-1045-2.

[img] Text
Liebetrau et.al.pdf - Accepted Version
Restricted to Registered users only

Download (7Mb) | Contact

Supplementary data:

Abstract

Continuous surface cores of cold-seep carbonates were recovered offshore Pacific Nicaragua and Costa Rica from 800 to 1,500-m water depths (Meteor 66/3) in order to decipher their evolution and methane enriched fluid emanation in contrasting geological settings. Cores from the mounds Iguana, Perezoso, Baula V and from the Jaco Scarp escarpment were used for a multi-method approach. For both settings aragonite was revealed as dominant authigenic carbonate phase in vein fillings and matrix cementation, followed by Mg-calcite as second most abundant. This common precipitation process of CaCO3 polymorphs could be ascribed as indirectly driven by chemical changes of the advecting pore water due to anaerobic oxidation of methane. A more direct influence of seep-related microbial activity on the authigenic mineral assemblage in both settings is probably reflected by the observed minor amounts of dolomite and a dolomite-like CaMg carbonate (MgCO3 ~ 42 %). δ13C data of Jaco Scarp samples are significantly lower (−43 to −56 ‰ PDB) than for mound samples (−22 to −36 ‰ PDB), indicating differences in fluid composition and origin. Noteworthy, δ18O values of Scarp samples correlate most closely with the ocean signature at their time of formation. Documenting the archive potential, a high resolution case study of a mound core implies at least 40 changes in fluid supply within a time interval of approximately 14 ky. As most striking difference, the age data indicate a late-stage downward-progressing cementation front for all three mound cap structures (approx. 2–5 cm/ky), but a significantly faster upward carbonate buildup in the bulging sediments on top of the scarp environment (approx. 120 cm/ky). The latter data set leads to the hypothesis of chemoherm carbonate emplacement in accord with reported sedimentation rates until decompression of the advective fluid system, probably caused by the Jaco Scarp landslide and dating this to approximately 13,000 years ago.

Document Type: Article
Additional Information: WOS:000343216700009
Keywords: Authigenic carbonates ; Marine geochemical archives ; Light stable isotopes ; U–Th geochronology ; Microbial induced mineral formation ; Slope bathymetry
Research affiliation: Kiel University > Faculty of Mathematics and Natural Sciences > Institute of Geosciences
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-MG Marine Geosystems
OceanRep > The Future Ocean - Cluster of Excellence > FO-R09
OceanRep > SFB 574
OceanRep > The Future Ocean - Cluster of Excellence
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems
Refereed: Yes
DOI etc.: 10.1007/s00531-014-1045-2
ISSN: 1437-3254
Projects: SFB574, Future Ocean
Contribution Number:
ProjectNumber
SFB 574205
Expeditions/Models:
Date Deposited: 02 Sep 2014 10:23
Last Modified: 23 May 2017 08:38
URI: http://eprints.uni-kiel.de/id/eprint/25527

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...