A comparison of early Paleogene export productivity and organic carbon burial flux for Maud Rise, Weddell Sea, and Kerguelen Plateau, south Indian Ocean

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doi: 10.1029/2009PA001916
Author(s): Faul, K. L.; Delaney, M. L.
Author Affiliation(s): Primary:
Mills College, Environmental Sciences Program, Oakland, CA, United States
Other:
University of California at Santa Cruz, United States
Volume Title: Paleoceanography
Source: Paleoceanography, 25(3). Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 106 refs.; illus., incl. 4 tables, geol. sketch map
Summary: Marine biological productivity has been invoked as a possible climate driver during the early Paleogene through its potential influence on atmospheric carbon dioxide concentrations. However, the relationship of export productivity (the flux of organic carbon (C) from the surface ocean to the deep ocean) to organic C burial flux (the flux of organic C from the deep ocean that is buried in marine sediments) is not well understood. We examine the various components involved with atmosphere-to-ocean C transfer by reconstructing early Paleogene carbonate and silica production (using carbonate and silica mass accumulation rates (MARs)); export productivity (using biogenic barium (bio-Ba) MARs); organic C burial flux (using reactive phosphorus (P) MARs); redox conditions (using uranium and manganese contents); and the fraction of organic C buried relative to export productivity (using reactive P to bio-Ba ratios). Our investigations concentrate on Paleocene/Eocene sections of Sites 689/690 from Maud Rise and Site 738 from Kerguelen Plateau. In both regions, export productivity, organic C burial flux, and the fraction of organic C buried relative to export productivity decreased from the Paleocene/early Eocene to the middle Eocene. A shift is indicated from an early Paleogene two-gyre circulation in which nutrients were not efficiently recycled to the surface via upwelling in these regions, to a circulation more like the present day with efficient recycling of nutrients to the surface ocean. Export productivity was enhanced for Kerguelen Plateau relative to Maud Rise throughout the early Paleogene, possibly due to internal waves generated by the plateau regardless of gyre circulation.
Year of Publication: 2010
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Barium; Burial; Calcium carbonate; Carbon; Cenozoic; Chemostratigraphy; Cores; Indian Ocean; Kerguelen Plateau; Leg 113; Leg 119; Lower Paleogene; Marine sediments; Maud Rise; Metals; ODP Site 689; ODP Site 690; ODP Site 738; Ocean Drilling Program; Ocean circulation; Organic carbon; Paleo-oceanography; Paleogene; Phosphorus; Productivity; Sedimentation; Sedimentation rates; Sediments; Silica; Southern Indian Ocean; Southern Ocean; Sulfates; Tertiary; Titanium; Weddell Sea
Coordinates: S643101 S643100 E0030600 E0030559
S650938 S650937 E0011218 E0011218
S624233 S624232 E0824715 E0824714
Record ID: 2013034372
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