Stable carbon and oxygen isotope ratios of benthic and planktonic foraminifera of ODP Hole 171-1049C

DOI

Ocean anoxic events were periods of high carbon burial that led to drawdown of atmospheric carbon dioxide, lowering of bottom-water oxygen concentrations and, in many cases, significant biological extinction (Arthur et al., 1990; Erbacher et al., 1996, doi:10.1130/0091-7613(1996)0242.3.CO;2; Kuypers et al., 1999, doi:10.1038/20659; Jenkyns, 1997; Hochuli et al., 1999, doi:10.1130/0091-7613(1999)0272.3.CO;2). Most ocean anoxic events are thought to be caused by high productivity and export of carbon from surface waters which is then preserved in organic-rich sediments, known as black shales. But the factors that triggered some of these events remain uncertain. Here we present stable isotope data from a mid-Cretaceous ocean anoxic event that occurred 112 Myr ago, and that point to increased thermohaline stratification as the probable cause. Ocean anoxic event 1b is associated with an increase in surface-water temperatures and runoff that led to decreased bottom-water formation and elevated carbon burial in the restricted basins of the western Tethys and North Atlantic. This event is in many ways similar to that which led to the more recent Plio-Pleistocene Mediterranean sapropels, but the greater geographical extent and longer duration (~46 kyr) of ocean anoxic event 1b suggest that processes leading to such ocean anoxic events in the North Atlantic and western Tethys were able to act over a much larger region, and sequester far more carbon, than any of the Quaternary sapropels.

Supplement to: Erbacher, Jochen; Huber, Brian T; Norris, Richard D; Markey, Molly (2000): Increased thermohaline stratification as a possible cause for an ocean anoxic event in the Cretaceous period. Nature, 409(6818), 325-327

Identifier
DOI https://doi.org/10.1594/PANGAEA.769750
Related Identifier https://doi.org/10.1038/35053041
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.769750
Provenance
Creator Erbacher, Jochen ORCID logo; Huber, Brian T ORCID logo; Norris, Richard D ORCID logo; Markey, Molly
Publisher PANGAEA
Publication Year 2000
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 398 data points
Discipline Earth System Research
Spatial Coverage (-76.112 LON, 30.142 LAT); Blake Nose, North Atlantic Ocean