Clay mineral continental amplifier for marine carbon sequestration in a greenhouse ocean

Martin J. Kennedy, Thomas Wagner

Research output: Contribution to journalArticle

78 Citations (Scopus)

Abstract

The majority of carbon sequestration at the Earth's surface occurs in marine continental margin settings within fine-grained sediments whose mineral properties are a function of continental climatic conditions. We report very high mineral surface area (MSA) values of 300 and 570 m(2) g in Late Cretaceous black shales from Ocean Drilling Program site 959 of the Deep Ivorian Basin that vary on subcentennial time scales corresponding with abrupt increases from approximately 3 to approximately 18% total organic carbon (TOC). The observed MSA changes with TOC across multiple scales of variability and on a sample-by-sample basis (centimeter scale), provides a rigorous test of a hypothesized influence on organic carbon burial by detrital clay mineral controlled MSA. Changes in TOC also correspond with geochemical and sedimentological evidence for water column anoxia. Bioturbated intervals show a lower organic carbon loading on mineral surface area of 0.1 mg-OCm(-2) when compared to 0.4 mg-OCm(-2) for laminated and sulfidic sediments. Although either anoxia or mineral surface protection may be capable of producing TOC of

Original languageEnglish
Pages (from-to)9776-9781
Number of pages6
JournalProceedings of the National Academy of Sciences
Volume108
Issue number24
DOIs
Publication statusPublished - 14 Jun 2011

Keywords

  • climate change
  • cretaceous ocean
  • source rocks
  • ocean dead zones
  • ORGANIC-MATTER PRESERVATION
  • AFRICAN CLIMATE VARIABILITY
  • EASTERN TROPICAL ATLANTIC
  • SURFACE-AREA
  • BLACK-SHALE
  • MARGIN SEDIMENTS
  • IVORY-COAST
  • OXYGEN
  • ACCUMULATION
  • DEGRADATION

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