HR: 0830h
AN: PP31B-0255    [PDF]
TI: A Benthic Foraminiferal Assessment of Holocene Oceanographic Change: Northern Antarctic Peninsula Margin
AU: * Szymcek, P B
EM: pszymcek@hotmail.com
AF: Southern Illinois University, Department of Geology, Carbondale, IL 62901-4324 United States
AU: Ishman, S E
EM: sishman@geo.siu.edu
AF: Southern Illinois University, Department of Geology, Carbondale, IL 62901-4324 United States
AU: Domack, E W
EM: edomack@hamilton.edu
AF: Hamilton College, Department of Geology, Clinton, NY 13323 United States
AU: Leventer, A
EM: aleventer@mail.colgate.edu
AF: Colgate University, Department of Geology, Hamilton, NY 13346 United States
AB: A 20.53 meter sediment sequence of Holocene glacio-marine sediments was recovered in core NBP0003-JPC38 from the Vega Drift, northern Antarctic Peninsula. Samples were collected every 4 cm from JPC38 for foraminiferal analyses to determine Holocene paleoceanographic and paleoclimatic variability of the northern Antarctic Peninsula margin. The foraminiferal data were analyzed using principle component and cluster analyses. Results of these analyses show significant stratigraphic changes in the benthic foraminiferal record of the Vega Drift. Transfer function analysis of the foraminiferal data from JPC38, using modern foraminiferal biofacies of the Antarctic Peninsula margin, indicate significant Holocene oceanographic changes. Two dominant assemblages characterize the core, the {\it Textularia weisneri} assemblage and the {\it Stainforthia fusiformis} assemblage. The bottom-most section of the core, 16.0 meters to base, is dominated by the calcareous {\it S. fusiformis} assemblage that also occurs in several abrupt intervals within the upper 16 meters of the core. This assemblage is characterized by abundant calcareous forms including {\it Globocassidulina biora, G. subglobosa, Nonionella iridea} and the planktonic species {\it Neogloboquadrina pachyderma}. The {\it S. fusiformis} assemblage has greatest affinities to modern assemblages found in the higher productivity areas of the Larsen Ice Shelf and western Antarctic Peninsula. The top 16.00 meters ($\sim$7000 yrs. BP to recent) of the core is dominated by agglutinated forms, and defined by the {\it Textularia weisneri} assemblage. The unaltered {\it T. weisneri} assemblage is similar to modern assemblages directly to the south of the Vega Drift in the Prince Gustav Channel. Most agglutinated forms tend to decrease downcore, and comparisons to modern analogues imply post-depositional disintegration. The altered assemblage is dominated by {\it Miliammina arenacea}, which resists taphonomic dissolution. Interpretation of the results from the foraminiferal analyses provides important paleoceanographic information related to the depositional architecture of the Vega Drift as interpreted from its sediment thickness, distribution and internal structures.
DE: 1600 GLOBAL CHANGE (New category)
DE: 3030 Micropaleontology
DE: 3344 Paleoclimatology
DE: 4267 Paleoceanography
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting