Cowan, Ellen A. (2002): Identification of the glacial signal from the Antarctic Peninsula since 3.0 Ma at Site 1101 in a continental rise sediment drift

Leg/Site/Hole:
ODP 178
ODP 178 1101
Identifier:
2003-022405
georefid

10.2973/odp.proc.sr.178.206.2001
doi

Creator:
Cowan, Ellen A.
Appalachian State University, Department of Geology, Boone, NC, United States
author

Identification:
Identification of the glacial signal from the Antarctic Peninsula since 3.0 Ma at Site 1101 in a continental rise sediment drift
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
Sediment drifts on the continental rise west of the Antarctic Peninsula received fine-grained sediment and ice-rafted debris (IRD) directly from the continental shelf and thus indirectly record the history of West Antarctic glaciation. Site 1101 contains a 218-m-thick, nearly continuous section extending from the late Pliocene to the Holocene. To assess the presence of calving glaciers at sea level in the Antarctic Peninsula region, the mass accumulation rate (MAR) of IRD was calculated using the weight percent terrigenous sand fraction (250 mu m to 2 mm). IRD MAR is cyclic throughout, with small peaks alternating with periods of low or no IRD. Many cycles have a sawtooth pattern that increases gradually to the peak then abruptly decreases to zero. This pattern is consistent with rapid disintegration of ice streams and release of icebergs from the continental shelf. Three unusually large peaks (three to five times the size of other peaks) occurred at approximately 2.8, 1.9, and 0.88 Ma and indicate periods of intense ice rafting. Lithofacies were described in detail using X-radiographs and core descriptions for the interval from 1.34 to 0.54 Ma. Glacial units are represented by thickly laminated mud deposited by distal turbidites and meltwater plumes. Less commonly, thinly laminated sediment formed by contour currents and diamicton by intense ice rafting. Interglacials are represented by foraminifer-bearing mud with IRD. Ice rafting appears to have increased in the later part of the glacial period and remained high in the interglacial period.
Coverage:Geographic coordinates:
North:-64.2220
West:-70.1540East: -70.1540
South:-64.2220

Stratigraphy; Antarctic Ocean; Antarctic Peninsula; Antarctica; biostratigraphy; Cenozoic; clastic sediments; climate change; continental rise; cores; debris; depositional environment; drift; Foraminifera; grain size; Holocene; ice rafting; Invertebrata; Leg 178; lithofacies; marine sediments; microfossils; Neogene; Ocean Drilling Program; ocean floors; ODP Site 1101; paleoclimatology; Pliocene; Protista; Quaternary; sedimentation; sedimentation rates; sediments; Tertiary; upper Pliocene;

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