Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene
Marine 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 assessin...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19930022692 2023-05-15T14:04:19+02:00 Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene Berkman, Paul Arthur Unclassified, Unlimited, Publicly available Jul 1, 1993 http://ntrs.nasa.gov/search.jsp?R=19930022692 unknown http://ntrs.nasa.gov/search.jsp?R=19930022692 Accession ID: 93N31881 No Copyright Other Sources 46 NASA. Goddard Space Flight Center, The First Annual West Antarctic Ice Sheet (WAIS) Science Workshop; p 5 1993 ftnasantrs 2012-02-15T19:56:21Z Marine 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. Other/Unknown Material Antarc* Antarctic Antarctica Ice Sheet McMurdo Sound NASA Technical Reports Server (NTRS) Antarctic West Antarctic Ice Sheet McMurdo Sound |
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NASA Technical Reports Server (NTRS) |
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46 Berkman, Paul Arthur Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene |
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description |
Marine 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. |
format |
Other/Unknown Material |
author |
Berkman, Paul Arthur |
author_facet |
Berkman, Paul Arthur |
author_sort |
Berkman, Paul Arthur |
title |
Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene |
title_short |
Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene |
title_full |
Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene |
title_fullStr |
Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene |
title_full_unstemmed |
Macrofossil records of West Antarctic Ice Sheet retreat during the Holocene |
title_sort |
macrofossil records of west antarctic ice sheet retreat during the holocene |
publishDate |
1993 |
url |
http://ntrs.nasa.gov/search.jsp?R=19930022692 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Antarctic West Antarctic Ice Sheet McMurdo Sound |
geographic_facet |
Antarctic West Antarctic Ice Sheet McMurdo Sound |
genre |
Antarc* Antarctic Antarctica Ice Sheet McMurdo Sound |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet McMurdo Sound |
op_source |
Other Sources |
op_relation |
http://ntrs.nasa.gov/search.jsp?R=19930022692 Accession ID: 93N31881 |
op_rights |
No Copyright |
_version_ |
1766275350559457280 |