Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land
We report concentrations of cosmogenic 10Be, 26Al, 36Cl, and 41Ca in the metal phase of 26 ordinary chondrites from Frontier Mountain (FRO), Antarctica, as well as cosmogenic 14C in eight and noble gases in four bulk samples. Thirteen out of 14 selected H chondrites belong to two previously identifi...
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ftunivarizonaojs:oai:journals.uair.arizona.edu:article/15297 2023-05-15T13:42:28+02:00 Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land Welten, K. C. Nishiizumi, K. Caffee, M. W. Hillegonds, D. J. Johnson, J. A. Jull, A. J. T. Wieler, R. Folco, L. 2006-01-01 application/pdf https://journals.uair.arizona.edu/index.php/maps/article/view/15297 eng eng Meteoritics & Planetary Science Archives https://journals.uair.arizona.edu/index.php/maps/article/view/15297/15285 https://journals.uair.arizona.edu/index.php/maps/article/view/15297 Meteoritics & Planetary Science Archives; Vol 41, No 7 (2006); 1081-1094 1945-5100 1086-9379 Terrestrial ages;paired Meteorites;Antarctic meteorites;cosmogenic Isotopes info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article 2006 ftunivarizonaojs 2020-11-14T17:53:00Z We report concentrations of cosmogenic 10Be, 26Al, 36Cl, and 41Ca in the metal phase of 26 ordinary chondrites from Frontier Mountain (FRO), Antarctica, as well as cosmogenic 14C in eight and noble gases in four bulk samples. Thirteen out of 14 selected H chondrites belong to two previously identified pairing groups, FRO 90001 and FRO 90174, with terrestrial ages of ~40 and ~100 kyr, respectively. The FRO 90174 shower is a heterogeneous H3-6 chondrite breccia that probably includes more than 300 individual fragments, explaining the high H/L chondrite ratio (3.8) at Frontier Mountain. The geographic distribution of 19 fragments of this shower constrains ice fluctuations over the past 50-100 kyr to less than 40 m, supporting the stability of the meteorite trap over the last glacial cycle. The second H-chondrite pairing group, FRO 90001, is much smaller and its geographic distribution is mainly controlled by wind-transport. Most L-chondrites are younger than 50 kyr, except for the FRO 93009/01172 pair, which has a terrestrial age of ~500 kyr. These two old L chondrites represent the only surviving members of a large shower with a similar preatmospheric radius (~80 cm) as the FRO 90174 shower. The find locations of these two paired L-chondrite fragments on opposite sides of Frontier Mountain confirm the general glaciological model in which the two ice flows passing both ends of the mountain are derived from the same source area on the plateau. The 50 FRO meteorites analyzed so far represent 21 different falls. The terrestrial ages range from 6 kyr to 500 kyr, supporting the earlier proposed concentration mechanism. Article in Journal/Newspaper Antarc* Antarctic Antarctica Victoria Land Journals at the University of Arizona Antarctic Frontier Mountain ENVELOPE(160.333,160.333,-72.983,-72.983) Victoria Land |
institution |
Open Polar |
collection |
Journals at the University of Arizona |
op_collection_id |
ftunivarizonaojs |
language |
English |
topic |
Terrestrial ages;paired Meteorites;Antarctic meteorites;cosmogenic Isotopes |
spellingShingle |
Terrestrial ages;paired Meteorites;Antarctic meteorites;cosmogenic Isotopes Welten, K. C. Nishiizumi, K. Caffee, M. W. Hillegonds, D. J. Johnson, J. A. Jull, A. J. T. Wieler, R. Folco, L. Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land |
topic_facet |
Terrestrial ages;paired Meteorites;Antarctic meteorites;cosmogenic Isotopes |
description |
We report concentrations of cosmogenic 10Be, 26Al, 36Cl, and 41Ca in the metal phase of 26 ordinary chondrites from Frontier Mountain (FRO), Antarctica, as well as cosmogenic 14C in eight and noble gases in four bulk samples. Thirteen out of 14 selected H chondrites belong to two previously identified pairing groups, FRO 90001 and FRO 90174, with terrestrial ages of ~40 and ~100 kyr, respectively. The FRO 90174 shower is a heterogeneous H3-6 chondrite breccia that probably includes more than 300 individual fragments, explaining the high H/L chondrite ratio (3.8) at Frontier Mountain. The geographic distribution of 19 fragments of this shower constrains ice fluctuations over the past 50-100 kyr to less than 40 m, supporting the stability of the meteorite trap over the last glacial cycle. The second H-chondrite pairing group, FRO 90001, is much smaller and its geographic distribution is mainly controlled by wind-transport. Most L-chondrites are younger than 50 kyr, except for the FRO 93009/01172 pair, which has a terrestrial age of ~500 kyr. These two old L chondrites represent the only surviving members of a large shower with a similar preatmospheric radius (~80 cm) as the FRO 90174 shower. The find locations of these two paired L-chondrite fragments on opposite sides of Frontier Mountain confirm the general glaciological model in which the two ice flows passing both ends of the mountain are derived from the same source area on the plateau. The 50 FRO meteorites analyzed so far represent 21 different falls. The terrestrial ages range from 6 kyr to 500 kyr, supporting the earlier proposed concentration mechanism. |
format |
Article in Journal/Newspaper |
author |
Welten, K. C. Nishiizumi, K. Caffee, M. W. Hillegonds, D. J. Johnson, J. A. Jull, A. J. T. Wieler, R. Folco, L. |
author_facet |
Welten, K. C. Nishiizumi, K. Caffee, M. W. Hillegonds, D. J. Johnson, J. A. Jull, A. J. T. Wieler, R. Folco, L. |
author_sort |
Welten, K. C. |
title |
Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land |
title_short |
Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land |
title_full |
Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land |
title_fullStr |
Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land |
title_full_unstemmed |
Terrestrial ages, pairing, and concentration mechanism of Antarctic chondrites from Frontier Mountain, Northern Victoria Land |
title_sort |
terrestrial ages, pairing, and concentration mechanism of antarctic chondrites from frontier mountain, northern victoria land |
publisher |
Meteoritics & Planetary Science Archives |
publishDate |
2006 |
url |
https://journals.uair.arizona.edu/index.php/maps/article/view/15297 |
long_lat |
ENVELOPE(160.333,160.333,-72.983,-72.983) |
geographic |
Antarctic Frontier Mountain Victoria Land |
geographic_facet |
Antarctic Frontier Mountain Victoria Land |
genre |
Antarc* Antarctic Antarctica Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica Victoria Land |
op_source |
Meteoritics & Planetary Science Archives; Vol 41, No 7 (2006); 1081-1094 1945-5100 1086-9379 |
op_relation |
https://journals.uair.arizona.edu/index.php/maps/article/view/15297/15285 https://journals.uair.arizona.edu/index.php/maps/article/view/15297 |
_version_ |
1766168243906543616 |