Wagner, Thomas (1997): Deposition of organic matter to the modern and Pleistocene Equatorial Atlantic; links with African climate and marine productivity

Leg/Site/Hole:
ODP 108
ODP 159
ODP 108 663
ODP 108 664
ODP 159 959
Identifier:
1997-067886
georefid

10.1306/3B05BF4C-172A-11D7-8645000102C1865D
doi

Creator:
Wagner, Thomas
University of Bremen, Department of Geosciences, Bremen, Federal Republic of Germany
author

Identification:
Deposition of organic matter to the modern and Pleistocene Equatorial Atlantic; links with African climate and marine productivity
1997
In: Anonymous, AAPG Eastern Section and the Society for Organic Petrology joint meeting; abstracts
American Association of Petroleum Geologists, Tulsa, OK, United States
81
9
1566-1567
Modern and Pleistocene glacial/interglacial sedimentation in the eastern and central Equatorial Atlantic is well documented to be effectively controlled by changes in paleoproductivity and variable eolian dust supply from central African areas. These changes in paleoenvironmental conditions caused cyclic changes in the total amount and composition of sedimentary organic carbon preserved in deep sea sediments. Elevated accumulation of organic carbon, typically recorded during glacial periods, is commonly interpreted to record enhanced paleoproductivity closely related to glacially enforced wind stress. In order to calibrate organic petrological and organic geochemical characteristics of past deep sea sediments to modern climatic and oceanographic conditions in the eastern to central Equatorial Atlantic spatial distribution patterns of various organic proxies, e.g. of TOC, terrigenous and marine macerals, Rock-Eval, and d13Corg are presented for surface sediments. Special emphasis is drawn to compare the interpretation based on the well established organic carbon isotopic signal of marine sediments with new qualitative and quantitative results from maceral analysis. Glacial-interglacial changes in the deposition of organic matter are discussed for late Quaternary to Pleistocene sequences of open pelagic to near continental settings including new results from ODP Sites 664, 663, and 959. Lateral gradients in eolian supply of terrigenous organic matter from the African continent and temporal changes in paleoproductivity are recorded along the core transect. Quantitative data derived from maceral analysis obviously contradict with measured d13Corg signals probably indicating a variable overprint of the bulk d13Corg signal by isotopically heavy C4 plant material.
English
Coverage:Geographic coordinates:
North:75.0000
West:-80.0000East: 51.0000
South:-60.0000

Quaternary geology; Africa; Atlantic Ocean; C-13/C-12; calibration; carbon; Cenozoic; changes; controls; Equatorial Atlantic; glacial environment; Holocene; interglacial environment; interpretation; isotope ratios; isotopes; Leg 108; Leg 159; macerals; marine environment; marine sediments; Ocean Drilling Program; ODP Site 663; ODP Site 664; ODP Site 959; organic carbon; organic compounds; organic materials; paleo-oceanography; paleoclimatology; Plantae; Pleistocene; productivity; quantitative analysis; Quaternary; Rock-Eval; sediment supply; sedimentation; sediments; stable isotopes;

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