Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state
The Fe oxidation state and coordination number of 29 impact glass spherules recently recovered from the Transantarctic Mountains (Antarctica) have been determined by X-ray absorption near edge structure (XANES) spectroscopy. Based on geochemical, isotopic, and fission track data, these spherules are...
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ftunivpisairis:oai:arpi.unipi.it:11568/427673 2024-02-27T08:33:35+00:00 Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state Giuli G. Cicconi M. R. Eeckhout S. G. Pratesi G. Paris E. FOLCO, LUIGI Giuli, G. Cicconi, M. R. Eeckhout, S. G. Pratesi, G. Paris, E. Folco, Luigi 2014 STAMPA http://hdl.handle.net/11568/427673 https://doi.org/10.1111/maps.12283 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000334680200012 volume:49 firstpage:696 lastpage:705 numberofpages:10 journal:METEORITICS & PLANETARY SCIENCE http://hdl.handle.net/11568/427673 doi:10.1111/maps.12283 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84898844499 info:eu-repo/semantics/article 2014 ftunivpisairis https://doi.org/10.1111/maps.12283 2024-01-31T17:55:48Z The Fe oxidation state and coordination number of 29 impact glass spherules recently recovered from the Transantarctic Mountains (Antarctica) have been determined by X-ray absorption near edge structure (XANES) spectroscopy. Based on geochemical, isotopic, and fission track data, these spherules are considered as microtektites from the Australasian tektite/microtektite strewn field. Their find location is the farthest so far discovered from the possible source crater region, and their alkali content is the lowest compared with other published data on Australasian microtektite glasses. The Fe3+/(Fe2++Fe3+) ratio, determined from the analysis of the pre-edge peak energy position and integrated intensity, is below 0.1 (±0.04) for all the samples, and is comparable to that of most tektites and microtektites from the Australasian strewn field. Also, the pre-edge peak integrated intensity, which is sensitive to the average Fe coordination geometry, is comparable to that of other Australasian microtektites reported in the literature. The agreement of the Fe oxidation state and coordination number, between the Transantarctic Mountain microtektites (TAM) and the Australasian tektites and microtektites, further confirms the impact origin of these glass spherules and provides an independent suggestion that they represent a major extension southeastward of the Australasian strewn field. The fact that similar redox conditions are observed in tektites and microtektites within the Australasian strewn field regardless of the distance from the source crater area (up to approximately 11000 km) could be an important constraint for better understanding the different processes affecting microtektite formation and transport. The fact that the Fe oxidation state of microtektites does not increase with distance, as in the case of North American microtektites, means that thermal and redox histories of Australasian and TAM microtektites could differ significantly from those of North American microtektites. Article in Journal/Newspaper Antarc* Antarctica ARPI - Archivio della Ricerca dell'Università di Pisa Transantarctic Mountains Meteoritics & Planetary Science 49 4 696 705 |
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Open Polar |
collection |
ARPI - Archivio della Ricerca dell'Università di Pisa |
op_collection_id |
ftunivpisairis |
language |
English |
description |
The Fe oxidation state and coordination number of 29 impact glass spherules recently recovered from the Transantarctic Mountains (Antarctica) have been determined by X-ray absorption near edge structure (XANES) spectroscopy. Based on geochemical, isotopic, and fission track data, these spherules are considered as microtektites from the Australasian tektite/microtektite strewn field. Their find location is the farthest so far discovered from the possible source crater region, and their alkali content is the lowest compared with other published data on Australasian microtektite glasses. The Fe3+/(Fe2++Fe3+) ratio, determined from the analysis of the pre-edge peak energy position and integrated intensity, is below 0.1 (±0.04) for all the samples, and is comparable to that of most tektites and microtektites from the Australasian strewn field. Also, the pre-edge peak integrated intensity, which is sensitive to the average Fe coordination geometry, is comparable to that of other Australasian microtektites reported in the literature. The agreement of the Fe oxidation state and coordination number, between the Transantarctic Mountain microtektites (TAM) and the Australasian tektites and microtektites, further confirms the impact origin of these glass spherules and provides an independent suggestion that they represent a major extension southeastward of the Australasian strewn field. The fact that similar redox conditions are observed in tektites and microtektites within the Australasian strewn field regardless of the distance from the source crater area (up to approximately 11000 km) could be an important constraint for better understanding the different processes affecting microtektite formation and transport. The fact that the Fe oxidation state of microtektites does not increase with distance, as in the case of North American microtektites, means that thermal and redox histories of Australasian and TAM microtektites could differ significantly from those of North American microtektites. |
author2 |
Giuli, G. Cicconi, M. R. Eeckhout, S. G. Pratesi, G. Paris, E. Folco, Luigi |
format |
Article in Journal/Newspaper |
author |
Giuli G. Cicconi M. R. Eeckhout S. G. Pratesi G. Paris E. FOLCO, LUIGI |
spellingShingle |
Giuli G. Cicconi M. R. Eeckhout S. G. Pratesi G. Paris E. FOLCO, LUIGI Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state |
author_facet |
Giuli G. Cicconi M. R. Eeckhout S. G. Pratesi G. Paris E. FOLCO, LUIGI |
author_sort |
Giuli G. |
title |
Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state |
title_short |
Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state |
title_full |
Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state |
title_fullStr |
Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state |
title_full_unstemmed |
Australasian microtektites from Antarctica: XAS determination of the Fe oxidation state |
title_sort |
australasian microtektites from antarctica: xas determination of the fe oxidation state |
publishDate |
2014 |
url |
http://hdl.handle.net/11568/427673 https://doi.org/10.1111/maps.12283 |
geographic |
Transantarctic Mountains |
geographic_facet |
Transantarctic Mountains |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000334680200012 volume:49 firstpage:696 lastpage:705 numberofpages:10 journal:METEORITICS & PLANETARY SCIENCE http://hdl.handle.net/11568/427673 doi:10.1111/maps.12283 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84898844499 |
op_doi |
https://doi.org/10.1111/maps.12283 |
container_title |
Meteoritics & Planetary Science |
container_volume |
49 |
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4 |
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696 |
op_container_end_page |
705 |
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