Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology
Cosmogenic 3He, 26 Al, and 10Be were measured in Antarctic glacial deposits in the McMurdo Sound-Dry Valleys region to constrain surface exposure ages. Moraines deposited by the Taylor glacier, an outlet glacier of the East Antarctic Ice Sheet, have exposure ages from approx. 120 kyr to 2myr. 10Be a...
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ftdtic:ADA279392 2023-05-15T14:04:37+02:00 Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology Brook, Edward J. WOODS HOLE OCEANOGRAPHIC INSTITUTION MA 1994-02 text/html http://www.dtic.mil/docs/citations/ADA279392 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA279392 en eng http://www.dtic.mil/docs/citations/ADA279392 Approved for public release; distribution is unlimited. DTIC AND NTIS Geology Geochemistry and Mineralogy *GEOLOGIC AGE DETERMINATION *ANTARCTIC REGIONS *GLACIAL DEPOSITS THESES ROCK CYCLES DEPOSITS DRIFT ICE ALUMINUM WISCONSIN NUCLIDES ROSS SEA GLACIERS SEA ICE ISOTOPES HELIUM BERYLLIUM OCEANS SEA LEVEL VALLEYS MCMURDO SOUND(ANTARCTICA) Text 1994 ftdtic 2016-02-22T03:50:46Z Cosmogenic 3He, 26 Al, and 10Be were measured in Antarctic glacial deposits in the McMurdo Sound-Dry Valleys region to constrain surface exposure ages. Moraines deposited by the Taylor glacier, an outlet glacier of the East Antarctic Ice Sheet, have exposure ages from approx. 120 kyr to 2myr. 10Be and 3He ages of 122 +/- 29 and 134+ / -54 kyr, respectively, for the Taylor II moraine are consistent with deposition during isotope stage 5e (approx. 120 kyr) . Mean 10Be exposure ages for older moraines in the valley of 362 + or - 26 kyr (Taylor III), 1.1 + or 1 0.1 myr (Taylor IVa) and 1.9 + or - 0.1 myr (Taylor IVb) suggest that major ice sheet advances during the last 2 myr were similar in extent to changes during the last glacial-interglacial cycle. Exposure ages for the 'late Wisconsin' Ross Sea Drift, deposited on the coast of McMurdo Sound by the Ross Sea Ice Sheet, range from 8-106 kyr, suggesting that this deposit does not, as previously thought, represent a single ice advance in response to lowered sea level at the last glacial maximum. The data suggest instead that the Ross Sea Ice Sheet may have grounded and advanced on the coast several times during the last glacial period. Sponsored in part by Grant NSF-EAR91-06810. Text Antarc* Antarctic Antarctica Ice Sheet McMurdo Sound Ross Sea Sea ice Taylor Glacier Defense Technical Information Center: DTIC Technical Reports database Antarctic Ross Sea McMurdo Sound East Antarctic Ice Sheet Taylor Glacier ENVELOPE(162.167,162.167,-77.733,-77.733) |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Geology Geochemistry and Mineralogy *GEOLOGIC AGE DETERMINATION *ANTARCTIC REGIONS *GLACIAL DEPOSITS THESES ROCK CYCLES DEPOSITS DRIFT ICE ALUMINUM WISCONSIN NUCLIDES ROSS SEA GLACIERS SEA ICE ISOTOPES HELIUM BERYLLIUM OCEANS SEA LEVEL VALLEYS MCMURDO SOUND(ANTARCTICA) |
spellingShingle |
Geology Geochemistry and Mineralogy *GEOLOGIC AGE DETERMINATION *ANTARCTIC REGIONS *GLACIAL DEPOSITS THESES ROCK CYCLES DEPOSITS DRIFT ICE ALUMINUM WISCONSIN NUCLIDES ROSS SEA GLACIERS SEA ICE ISOTOPES HELIUM BERYLLIUM OCEANS SEA LEVEL VALLEYS MCMURDO SOUND(ANTARCTICA) Brook, Edward J. Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology |
topic_facet |
Geology Geochemistry and Mineralogy *GEOLOGIC AGE DETERMINATION *ANTARCTIC REGIONS *GLACIAL DEPOSITS THESES ROCK CYCLES DEPOSITS DRIFT ICE ALUMINUM WISCONSIN NUCLIDES ROSS SEA GLACIERS SEA ICE ISOTOPES HELIUM BERYLLIUM OCEANS SEA LEVEL VALLEYS MCMURDO SOUND(ANTARCTICA) |
description |
Cosmogenic 3He, 26 Al, and 10Be were measured in Antarctic glacial deposits in the McMurdo Sound-Dry Valleys region to constrain surface exposure ages. Moraines deposited by the Taylor glacier, an outlet glacier of the East Antarctic Ice Sheet, have exposure ages from approx. 120 kyr to 2myr. 10Be and 3He ages of 122 +/- 29 and 134+ / -54 kyr, respectively, for the Taylor II moraine are consistent with deposition during isotope stage 5e (approx. 120 kyr) . Mean 10Be exposure ages for older moraines in the valley of 362 + or - 26 kyr (Taylor III), 1.1 + or 1 0.1 myr (Taylor IVa) and 1.9 + or - 0.1 myr (Taylor IVb) suggest that major ice sheet advances during the last 2 myr were similar in extent to changes during the last glacial-interglacial cycle. Exposure ages for the 'late Wisconsin' Ross Sea Drift, deposited on the coast of McMurdo Sound by the Ross Sea Ice Sheet, range from 8-106 kyr, suggesting that this deposit does not, as previously thought, represent a single ice advance in response to lowered sea level at the last glacial maximum. The data suggest instead that the Ross Sea Ice Sheet may have grounded and advanced on the coast several times during the last glacial period. Sponsored in part by Grant NSF-EAR91-06810. |
author2 |
WOODS HOLE OCEANOGRAPHIC INSTITUTION MA |
format |
Text |
author |
Brook, Edward J. |
author_facet |
Brook, Edward J. |
author_sort |
Brook, Edward J. |
title |
Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology |
title_short |
Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology |
title_full |
Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology |
title_fullStr |
Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology |
title_full_unstemmed |
Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology |
title_sort |
surface exposure geochronology using cosmogenic nuclides: applications in antarctic glacial geology |
publishDate |
1994 |
url |
http://www.dtic.mil/docs/citations/ADA279392 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA279392 |
long_lat |
ENVELOPE(162.167,162.167,-77.733,-77.733) |
geographic |
Antarctic Ross Sea McMurdo Sound East Antarctic Ice Sheet Taylor Glacier |
geographic_facet |
Antarctic Ross Sea McMurdo Sound East Antarctic Ice Sheet Taylor Glacier |
genre |
Antarc* Antarctic Antarctica Ice Sheet McMurdo Sound Ross Sea Sea ice Taylor Glacier |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet McMurdo Sound Ross Sea Sea ice Taylor Glacier |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA279392 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766275824652124160 |