Establishing criteria to distinguish oil-seep from methane-seep carbonates

Author(s)
Daniel Smrzka, Jennifer Zwicker, Andreas Klügel, Patrick Monien, Wolfgang Bach, Gerhard Bohrmann, Jörn Ludwig Peckmann
Abstract

Hydrocarbon seeps harbor copious chemosynthesis-dependent life, the traces of which are preserved in the fossil record within authigenic carbonates. These environments are mostly characterized by seepage of methane-rich fluids, yet numerous crude oil-dominated seeps have been discovered in recent years. Oil seepage has a profound influence on the local fauna, but recognizing such seeps in the rock record remains elusive. This study presents new geo-chemical data that will allow for a more confident identification of ancient oil-seep deposits. Geochemical data from modern and ancient seep limestones reveal that oil-dominated seep carbonates are enriched in rare earth elements and uranium compared to their methane-dominated counterparts. These trace element patterns have the potential to serve as a basis for an improved understanding of the adaptation of chemosynthetic life to oil seepage, and to better constrain the marine carbon cycle in the geologic past.

Organisation(s)
Department of Geology
External organisation(s)
Universität Bremen, Universität Hamburg
Journal
Geology
Volume
44
Pages
667-670
No. of pages
4
ISSN
0091-7613
DOI
https://doi.org/10.1130/G38029.1
Publication date
07-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
105105 Geochemistry, 105121 Sedimentology
Keywords
ASJC Scopus subject areas
Geology
Portal url
https://ucrisportal.univie.ac.at/en/publications/2fa12fd0-260c-4ba6-b4d8-60e7a00eef0e