Weinheimer, Amy L. (2002): Radiolarians in sediments from the Palmer Deep, Antarctica, Leg 178, Site 1098

Leg/Site/Hole:
ODP 178
ODP 178 1098
Identifier:
2003-022428
georefid

10.2973/odp.proc.sr.178.221.2002
doi

Creator:
Weinheimer, Amy L.
Scripps Institution of Oceanography, Climate Research Division, La Jolla, CA, United States
author

Identification:
Radiolarians in sediments from the Palmer Deep, Antarctica, Leg 178, Site 1098
2002
In: Baker, Peter F. (editor), Camerlenghi, Angelo (editor), Acton, Gary D. (editor), Brachfeld, Stefanie A., Cowan, Ellen A., Daniels, James, Domack, Eugene W., Escutia, Carlota, Evans, Andrew J., Eyles, Nicholas, Guyodo, Yohan J. B., Hatfield, Kate L., Iorio, Marina, Iwai, Masao, Kyte, Frank T., Lauer, Christine, Maldonado, Andres, Moerz, Tobias, Osterman, Lisa E., Pudsey, Carol J., Schuffert, Jeffrey D., Sjunneskog, Charlotte M., Weinheimer, Amy L., Williams, Trevor, Winter, Diane M., Wolf-Welling, Thomas C. W., Ramsay, Anthony T. S. (editor), Proceedings of the Ocean Drilling Program, scientific results, Antarctic glacial history and sea-level change; covering Leg 178 of the cruises of the drilling vessel JOIDES Resolution; Punta Arenas, Chile, to Cape Town, South Africa; sites 1095-1103; 5 February-9 April 1998
Texas A&M University, Ocean Drilling Program, College Station, TX, United States
178
Palmer Deep is a series of three glacially overdeepened basins on the Antarctic Peninsula shelf, approximately 20 km southwest of Anvers Island. Site 1098 (64 degrees 51.72'S, 64 degrees 12.48'W) was drilled in the shallowest basin, Basin I, at 1012 m water depth. The sediment recovered was primarily laminated, siliceous, biogenic, pelagic muds alternating with siliciclastic hemipelagic sediments (Barker, Camerlenghi, Acton, et al., 1999). Sedimentation rates of 0.1725 cm/yr in the upper 25 m and 0.7-0.80 cm/yr in the lower 25 m of the core have been estimated from 14C (Domack et al., 2001). The oldest datable sediments have an age of approximately 13 ka and were underlain by diamicton sediments of the last glacial maximum (Domack et al., 2001). The large-scale water-mass distribution and circulation in the vicinity of Palmer Deep is dominated by Circumpolar Deep Water (CDW) below 200 m (Hofmann et al., 1996). Palmer Deep is too far from the coast to be influenced by glacial meltwater and cold-tongue generation associated with it (Domack and Williams, 1990; Dixon and Domack, 1991). Circulation patterns in the Palmer Deep area are not well understood, but evidence suggests southward flow across Palmer Deep from Anvers Island to Renaud Island (Kock and Stein, 1978). The water south of Anvers Island is nearly open with loose pack ice from February through May. The area is covered with sea ice beginning in June (Gloersen et al., 1992; Leventer et al., 1996). Micropaleontologic data from the work of Leventer et al. (1996) on a 9-m piston core has revealed circulation and climate patterns for the past 3700 yr in the Palmer Deep. The benthic foraminifer assemblage is dominated by two taxa, Bulimina aculeata and Bolivina pseudopunctata, which are inversely related. High relative abundances of B. aculeata occur cyclically over a period of approximately 230 yr. The assemblage associated with high abundance of B. aculeata in Palmer Deep resembles that from the Bellingshausen shelf, which is associated with CDW. In addition to the faunal evidence, hydrographic data indicate incursions of CDW into Palmer Deep (Leventer et al., 1996). A distinctive diatom assemblage dominated by a single genus was associated with peaks in B. aculeata, whereas a few different assemblages were associated with lows in B. aculeata. Leventer et al. (1996) interpreted the variability in diatom assemblages as an indication of changes in productivity associated with changes in water column stability.
Coverage:Geographic coordinates:
North:-64.5143
West:-64.1228East: -64.1228
South:-64.5143

Quaternary geology; algae; Antarctic Ocean; Antarctic Peninsula; Antarctica; assemblages; bioclastic sedimentation; biostratigraphy; Cenozoic; cores; correlation; diatoms; Foraminifera; glacial environment; glaciomarine environment; ice; Invertebrata; Leg 178; marine environment; microfossils; Ocean Drilling Program; ocean floors; ODP Site 1098; paleo-oceanography; paleoclimatology; Palmer Deep; Plantae; Pleistocene; Protista; Quaternary; Radiolaria; sea ice; sedimentation; upper Pleistocene;

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