Marine 187Os/188Os isotope stratigraphy reveals the interaction of volcanism and ocean circulation during Oceanic Anoxic Event 2

Alice D.C. Du Vivier*, David Selby, Bradley B. Sageman, Ian Jarvis, Darren R. Gröcke, Silke Voigt

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

124 Scopus citations

Abstract

High-resolution osmium (Os) isotope stratigraphy across the Cenomanian-Turonian Boundary Interval from 6 sections for four transcontinental settings has produced a record of seawater chemistry that demonstrates regional variability as a function of terrestrial and hydrothermal inputs, revealing the impact of palaeoenvironmental processes. In every section the 187Os/188Os profiles show a comparable trend; radiogenic values in the lead up to Oceanic Anoxic Event 2 (OAE 2); an abrupt unradiogenic trend at the onset of OAE 2; an unradiogenic interval during the first part of OAE 2; and a return to radiogenic values towards the end of the event, above the Cenomanian-Turonian boundary. The unradiogenic trend in 187Os/188Os is synchronous in all sections. Previous work suggests that activity of the Caribbean LIP (Large Igneous Province) was the source of unradiogenic Os across the OAE 2 and possibly an instigator of anoxia in the oceans. Here we assess this hypothesis and consider the influence of activity from other LIPs; such as the High Arctic LIP.A brief shift to high radiogenic 187Os/188Os values occurred in the Western Interior Seaway before the onset of OAE 2. We evaluate this trend and suggest that a combination of factors collectively played critical roles in the initiation of OAE 2; differential input of nutrients from continental and volcanogenic sources, coupled with efficient palaeocirculation of the global ocean and epeiric seas, enhanced productivity due to higher nutrient availability, which permitted penecontemporaneous transport of continental and LIP-derived nutrients to trans-equatorial basins.

Original languageEnglish (US)
Pages (from-to)23-33
Number of pages11
JournalEarth and Planetary Science Letters
Volume389
DOIs
StatePublished - Mar 1 2014

Keywords

  • Carbon
  • Caribbean LIP
  • Global warming
  • OAE 2
  • Palaeocirculation

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Marine <sup>187</sup>Os/<sup>188</sup>Os isotope stratigraphy reveals the interaction of volcanism and ocean circulation during Oceanic Anoxic Event 2'. Together they form a unique fingerprint.

Cite this