4. Data Report: Late Pleistocene
and Holocene Sedimentation
on the Marion Plateau: Data
from Precruise ODP Leg 194 Site Survey Gravity Cores¹

P.R. Heck,^{2, 3} F.S. Anselmetti,³ and A.R. Isern⁴

ABSTRACT

Biostratigraphic, sedimentologic, and geochemical analyses of hemipelagic periplatform sediments from shallow gravity cores taken during the Ocean Drilling Program Leg 194 site survey reveal that, despite the strong currents and almost infilled intraplatform bathymetric depressions, recent sedimentation at the location of the Leg 194 drill sites recorded glacial–interglacial cycles. Sediment analyses included determination of sediment type, carbonate content, bulk stable oxygen isotope composition, and calcareous nannofossil zones. Glacial periods, identified by elevated bulk ¹⁸O, are characterized by darker sediment color, coarser grain size, and lower carbonate content, whereas interglacial periods yield lighter-colored, finer, and carbonate-rich sediments. These data from the shallowmost few meters of Marion Plateau sediments complement the subsurface information of Leg 194 holes, in which the top few meters have not been analyzed in such a high-resolution fashion. In addition, these gravity cores are more likely to have recovered the sediments closest to the sediment/water interface as compared to the hydraulic piston cores collected during Leg 194.

¹ Heck, P.R., Anselmetti, F.S., and Isern, A.R., 2004. Data report: Late Pleistocene and Holocene sedimentation on the Marion Plateau: data from precruise ODP Leg 194 site survey gravity cores. In Anselmetti, F.S., Isern, A.R., Blum, P., and Betzler, C. (Eds.), Proc. ODP, Sci. Results, 194 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/194_SR/006/006.htm>. [Cited YYYY-MM-DD]

² Institute for Isotope Geology and Mineral Resources, NO C61, ETH Zurich, 8092 Zurich, Switzerland. heck@erdw.ethz.ch

³ Geological Institute, ETH Zurich, 8092 Zurich, Switzerland.

⁴ Ocean Technology and Interdisciplinary Coordination, Division of Ocean Sciences, National Science Foundation, 4201 Wilson Boulevard, Arlington VA 22230, USA.

Initial receipt: 19 July 2003
Acceptance: 9 August 2004
Web publication: 26 October 2004
Ms 194SR-006