Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma
Antarctic H chondrites show a different range of induced thermoluminescence properties compared with those of H chondrites that have fallen elsewhere in the world. Recent noble gas data of Schultz et al. (1991) show that this difference is displayed most dramatically by meteorites with cosmic-ray ex...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19910050072 2023-05-15T13:53:23+02:00 Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma Sears, Derek W. G. Benoit, Paul Batchelor, J. David Unclassified, Unlimited, Publicly available Apr 1, 1991 http://ntrs.nasa.gov/search.jsp?R=19910050072 unknown http://ntrs.nasa.gov/search.jsp?R=19910050072 Accession ID: 91A34695 Copyright Other Sources 91 Geochimica et Cosmochimica Acta; 55; 1193-119 1991 ftnasantrs 2012-02-15T19:00:55Z Antarctic H chondrites show a different range of induced thermoluminescence properties compared with those of H chondrites that have fallen elsewhere in the world. Recent noble gas data of Schultz et al. (1991) show that this difference is displayed most dramatically by meteorites with cosmic-ray exposure ages less than 20 Ma, and they confirm that the differences cannot be attributed to weathering or to the presence of a great many fragments of an unusual Antarctic meteorite. Annealing experiments on an H5 chondrite, and other measurements on a variety of ordinary chondrites, have shown that induced TL properties are sensitive to the thermal histories of the meteorities. It is concluded that the events(s) that released the less than 20 Ma samples, which are predominantly those with exposure ages of 8 + or - 2 Ma, produced two groups with different thermal histories, one that came to earth several 100,000 years ago and that are currently only found in Antarctica, and one that is currently falling on the earth. Other/Unknown Material Antarc* Antarctic Antarctica NASA Technical Reports Server (NTRS) Antarctic |
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91 |
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91 Sears, Derek W. G. Benoit, Paul Batchelor, J. David Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma |
topic_facet |
91 |
description |
Antarctic H chondrites show a different range of induced thermoluminescence properties compared with those of H chondrites that have fallen elsewhere in the world. Recent noble gas data of Schultz et al. (1991) show that this difference is displayed most dramatically by meteorites with cosmic-ray exposure ages less than 20 Ma, and they confirm that the differences cannot be attributed to weathering or to the presence of a great many fragments of an unusual Antarctic meteorite. Annealing experiments on an H5 chondrite, and other measurements on a variety of ordinary chondrites, have shown that induced TL properties are sensitive to the thermal histories of the meteorities. It is concluded that the events(s) that released the less than 20 Ma samples, which are predominantly those with exposure ages of 8 + or - 2 Ma, produced two groups with different thermal histories, one that came to earth several 100,000 years ago and that are currently only found in Antarctica, and one that is currently falling on the earth. |
format |
Other/Unknown Material |
author |
Sears, Derek W. G. Benoit, Paul Batchelor, J. David |
author_facet |
Sears, Derek W. G. Benoit, Paul Batchelor, J. David |
author_sort |
Sears, Derek W. G. |
title |
Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma |
title_short |
Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma |
title_full |
Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma |
title_fullStr |
Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma |
title_full_unstemmed |
Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma |
title_sort |
evidence for differences in the thermal histories of antarctic and non-antarctic h chondrites with cosmic-ray exposure ages less than 20 ma |
publishDate |
1991 |
url |
http://ntrs.nasa.gov/search.jsp?R=19910050072 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Other Sources |
op_relation |
http://ntrs.nasa.gov/search.jsp?R=19910050072 Accession ID: 91A34695 |
op_rights |
Copyright |
_version_ |
1766258432628752384 |