6. Miocene-Pleistocene Sedimentary Record of Carbon Burial under the Benguela Current Upwelling System, Southwestern Margin of Africa1

Philip A. Meyers2


The amounts of inorganic and organic carbon in Miocene-Pleistocene sediments from Ocean Drilling Program Sites 1081, 1082, 1084, 1085, and 1087 and Deep Sea Drilling Project Site 532 on the margin of southwest Africa are summarized. Concentrations of CaCO3 are consistently ~75 wt% at Sites 1085 and 1087 in the Cape Basin but drop below 25 wt% near the Pliocene/Pleistocene boundary at Sites 532, 1081, 1082, and 1084 in Walvis Basin and on Walvis Ridge because of greater opal production during this period. Total organic carbon concentrations range between 0.1 and 18 wt% and are highest in sediments deposited at Site 1084 in Walvis Basin. Organic matter is predominantly marine in origin at all locations, as indicated by a combination of Rock-Eval and C/N measurements. Both the production and preservation of organic matter appear to have fluctuated regularly during the evolution of this upwelling system.

1 Meyers, P.A., 2001. Miocene-Pleistocene sedimentary record of carbon burial under the Benguela Current upwelling system, southwestern margin of Africa. In Wefer, G., Berger, W.H., and Richter, C. (Eds.), Proc. ODP, Sci. Results, 175 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/175_SR/chap_06/chap_06.htm>. [Cited YYYY-MM-DD]

2 Marine Geology and Geochemistry Program, Department of Geological Sciences, The University of Michigan, Ann Arbor MI 48109-1063, USA. pameyers@umich.edu

Initial receipt: 16 February 2000
Accepted: 14 September 2000
Web publication: 10 April 2001
Ms 175SR-212