A clay mineral continental amplifier for marine carbon sequestration in a greenhouse ocean
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- Professor Martin Kennedy
- Professor Thomas Wagner
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| Author(s) | | Kennedy M, Wagner T |
| Publication type | | Article |
| Journal | | Proceedings of the National Academy of Sciences |
| Year | | 2011 |
| Volume | | 108 |
| Issue | | 24 |
| Pages | | 9776-9781 |
| ISSN (print) | | 0027-8424 |
| ISSN (electronic) | | 1091-6490 |
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| Full text for this publication is not currently held within this repository. Alternative links are provided below where available. |
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| 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 m2 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-OC m-2 when compared to 0.4 mg-OC m-2 for laminated and sulfidic sediments. Although either anoxia or mineral surface protection may be capable of producing TOC of < 5%, when brought together they produced the very high TOC (10–18%) apparent in these sediments. This nonlinear response in carbon burial resulted from minor precession-driven changes of continental climate influencing clay mineral properties and runoff from the African continent. This study identifies a previously unrecognized land–sea connection among continental weathering, clay mineral production, and anoxia and a nonlinear effect on marine carbon sequestration during the Coniacian-Santonian Oceanic Anoxic Event 3 in the tropical eastern Atlantic. |
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| Publisher | | National Academy of Sciences |
| URL | | http://dx.doi.org/10.1073/pnas.1018670108 |
| DOI | | 10.1073/pnas.1018670108 |
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