Rare earth elements of seep carbonates

Author(s)
D. Feng, Z. Lin, Y. Bian, D. Chen, J. Peckmann, G. Bohrmann, H.H. Roberts
Abstract

At marine seeps, methane is microbially oxidized resulting in the precipitation of carbonates close to the seafloor. Methane oxidation leads to sulfate depletion in sediment pore water, which induces a change in redox conditions. Rare earth element (REE) patterns of authigenic carbonate phases collected from modern seeps of the Gulf of Mexico, the Black Sea, and the Congo Fan were analyzed. Different carbonate minerals including aragonite and calcite with different crystal habits have been selected for analysis. Total REE content (ΣREE) of seep carbonates varies widely, from 0.1. ppm to 42.5. ppm, but a common trend is that the ΣREE in microcrystalline phases is higher than that of the associated later phases including micospar, sparite and blocky cement, suggesting that ΣREE may be a function of diagenesis. The shale-normalized REE patterns of the seep carbonates often show different Ce anomalies even in samples from a specific site, suggesting that the formation conditions of seep carbonates are variable and complex. Overall, our results show that apart from anoxic, oxic conditions are at least temporarily common in seep environments.

Organisation(s)
Department of Geology
External organisation(s)
Chinese Academy of Sciences (CAS), University of the Chinese Academy of Sciences, Louisiana State University, Alexandria, Universität Bremen
Journal
Journal of Asian Earth Sciences
Volume
65
Pages
27-33
No. of pages
7
ISSN
1367-9120
DOI
https://doi.org/10.1016/j.jseaes.2012.09.002
Publication date
03-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
105121 Sedimentology, 105101 General geology
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/0a93c57f-6931-4c5a-8223-c1ccb012b4a1