Journal article

Organic carbon burial during OAE2 driven by changes in the locus of organic matter sulfurization

Morgan Reed Raven, David A Fike, Maya L Gomes, Samuel M Webb, Alexander S Bradley, Harry-Luke O McClelland

NATURE COMMUNICATIONS | NATURE PUBLISHING GROUP | Published : 2018

Abstract

Ocean Anoxic Event 2 (OAE2) was a period of dramatic disruption to the global carbon cycle when massive amounts of organic matter (OM) were buried in marine sediments via complex and controversial mechanisms. Here we investigate the role of OM sulfurization, which makes OM less available for microbial respiration, in driving variable OM preservation in OAE2 sedimentary strata from Pont d'Issole (France). We find correlations between the concentration, S:C ratio, S-isotope composition, and sulfur speciation of OM suggesting that sulfurization facilitated changes in carbon burial at this site as the chemocline moved in and out of the sediments during deposition. These patterns are reproduced b..

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Grants

Awarded by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences


Funding Acknowledgements

We are grateful to the Agouron Institute for financial support to M.R.R. and for the technical efforts of Melanie Suess, Stephanie Moore, Teresa Avila, and Jennifer Houghton at Washington University in St. Louis. We thank Matt Hurtgen and Brad Sageman at Northwestern University for helpful conversations about OAEs and for access to Pont d'Issole samples. Thanks also to Itay Halevy at the Weizmann Institute of Science for valuable discussions about the modeling aspect of this work. This work was enhanced by XAS analyses at the Stanford Synchrotron Radiation Laboratory under Rapid Access User Proposal 49705, as well as the efforts of SSRL staff. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515.