NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Macrofossil records of West Antarctic Ice Sheet retreat during the HoloceneMarine macrofossils in emerged beaches around Antarctica represent a geochemical framework for interpreting meltwater signatures associated with variations in the adjacent ice sheet margins during the last 10,000 years. In particular, mollusc species provide ideal experimental templates for assessing hydrochemical variations in Antarctic coastal marine environments because of their excellent preservation, high abundances, circumpolar distributions, and carbonate shells, which incorporate trace elements and stable isotopes. Modern samples of the bivalve Adamussium colbecki, which were collected across a depth gradient in the vicinity of a glacial meltwater stream in West McMurdo Sound, revealed shell trace element concentrations that were significantly higher above 10 meters because of their exposure to meltwater runoff. This meltwater signature also was reflected by the shell oxygen isotopic composition, which was in equilibrium with the ambient seawater, as demonstrated by the overlap between the predicted and actual O-(delta-18)sub w values. These modern samples provide analogs for interpreting the geochemical records in their fossils, which were based solely on molluscan fossils, complement the above geochemical data by suggesting that the rate of beach emergence fluctuated around Antarctica during the mid-Holocene. Paleoenvironmental analysis of macrofossils from emerged beaches represents a new direction in Antarctic research that can be used to assess changes in the margins of the ice sheets since the Last Glacial Maximum. The resolution of these analyses will be enhanced by collaborations that are developing with scientists who are conducting comparable studies in other coastal regions around the continent.
Document ID
19930022692
Document Type
Conference Paper
Authors
Berkman, Paul Arthur
(Ohio State Univ. Columbus, OH, United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1993
Publication Information
Publication: NASA. Goddard Space Flight Center, The First Annual West Antarctic Ice Sheet (WAIS) Science Workshop
Subject Category
Geophysics
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

IDRelationTitle19930022689Analytic PrimaryThe First Annual West Antarctic Ice Sheet (WAIS) Science Workshop
No Preview Available