10Be in Australasian microtektites compared to tektites: Size and geographic controls
International audience High Be-10 contents in tektites reported in literature are taken as evidence of a source material, melted at the impact site, enriched in atmospheric Be-10; i.e., a soil or sediment. In 0.8 Ma Australasian tektites, Be-10 content increases with distance from the putative impac...
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ftcollegfrance:oai:HAL:hal-01868053v1 2024-06-23T07:47:53+00:00 10Be in Australasian microtektites compared to tektites: Size and geographic controls Rochette, P. Braucher, R. Folco, L. Horng, C.S. Aumaître, G. Bourles, D.L. Keddadouche, K. Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Programma Nazionale di Ricerche in Antartide grant PNRA16_0029 Taiwan Ocean Research Institute MD97-2142 INSU/CNRS; Agence Nationale de la Recherche through "Projets thematiques d'excellence" program for the "Equipements d'excellence" ASTER-CEREGE action; Institut de recherche pour le developpement; A*MIDEX fundation "Pepiniere d'excellence" program ANR-10-EQPX-0024,ASTER-CEREGE,PLATEFORME DE GEOCHIMIE ISOTOPIQUE ASTER/CEREGE(2010) 2019 https://hal.science/hal-01868053 https://doi.org/10.1130/G45038.1 en eng HAL CCSD Geological Society of America info:eu-repo/semantics/altIdentifier/doi/10.1130/G45038.1 hal-01868053 https://hal.science/hal-01868053 doi:10.1130/G45038.1 PRODINRA: 450134 WOS: 000442904600019 ISSN: 0091-7613 EISSN: 1943-2682 Geology https://hal.science/hal-01868053 Geology, 2019, 46 (9), pp.803 - 806. ⟨10.1130/G45038.1⟩ [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology [SDE.MCG]Environmental Sciences/Global Changes [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment info:eu-repo/semantics/article Journal articles 2019 ftcollegfrance https://doi.org/10.1130/G45038.1 2024-06-13T23:39:52Z International audience High Be-10 contents in tektites reported in literature are taken as evidence of a source material, melted at the impact site, enriched in atmospheric Be-10; i.e., a soil or sediment. In 0.8 Ma Australasian tektites, Be-10 content increases with distance from the putative impact location in Indochina, with geographic averages from 69 x 10(6) atoms/g (Indochina) to 136 x 10(6) atoms/g (Australia). Here we report, for the first time, Be-10 contents in microtektites collected from Antarctica and the South China Sea. We show that microtektites are similar to 30 x 10(6) atoms/g richer in Be-10 than tektites from the same geographic areas. Antarctic microtektites, with an average Be-10 content of 184 x 10(6) atoms/g after correction for in situ production, are the richest impact glass ever measured. The simplest explanation for such systematic size and geographic trends is that the source depth of the melt within the target surface decreases with ejection velocity. Indeed, higher initial kinetic energy implies higher launch distances and higher fragmentation of the ejecta. Antarctic microtektite source depth may tentatively be restricted to the upper tens of centimeters at the impact site. Alternative models invoking a marine or loessic sediment source, or a secondary enrichment in the microtektite (either by atmospheric scavenging, selective fractionation by volatilization, or post-depositional contamination) fail to reproduce the observed relationships. Article in Journal/Newspaper Antarc* Antarctic Antarctica Collège de France: HAL Antarctic Geology 46 9 803 806 |
institution |
Open Polar |
collection |
Collège de France: HAL |
op_collection_id |
ftcollegfrance |
language |
English |
topic |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology [SDE.MCG]Environmental Sciences/Global Changes [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
spellingShingle |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology [SDE.MCG]Environmental Sciences/Global Changes [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Rochette, P. Braucher, R. Folco, L. Horng, C.S. Aumaître, G. Bourles, D.L. Keddadouche, K. 10Be in Australasian microtektites compared to tektites: Size and geographic controls |
topic_facet |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology [SDE.MCG]Environmental Sciences/Global Changes [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
description |
International audience High Be-10 contents in tektites reported in literature are taken as evidence of a source material, melted at the impact site, enriched in atmospheric Be-10; i.e., a soil or sediment. In 0.8 Ma Australasian tektites, Be-10 content increases with distance from the putative impact location in Indochina, with geographic averages from 69 x 10(6) atoms/g (Indochina) to 136 x 10(6) atoms/g (Australia). Here we report, for the first time, Be-10 contents in microtektites collected from Antarctica and the South China Sea. We show that microtektites are similar to 30 x 10(6) atoms/g richer in Be-10 than tektites from the same geographic areas. Antarctic microtektites, with an average Be-10 content of 184 x 10(6) atoms/g after correction for in situ production, are the richest impact glass ever measured. The simplest explanation for such systematic size and geographic trends is that the source depth of the melt within the target surface decreases with ejection velocity. Indeed, higher initial kinetic energy implies higher launch distances and higher fragmentation of the ejecta. Antarctic microtektite source depth may tentatively be restricted to the upper tens of centimeters at the impact site. Alternative models invoking a marine or loessic sediment source, or a secondary enrichment in the microtektite (either by atmospheric scavenging, selective fractionation by volatilization, or post-depositional contamination) fail to reproduce the observed relationships. |
author2 |
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Programma Nazionale di Ricerche in Antartide grant PNRA16_0029 Taiwan Ocean Research Institute MD97-2142 INSU/CNRS; Agence Nationale de la Recherche through "Projets thematiques d'excellence" program for the "Equipements d'excellence" ASTER-CEREGE action; Institut de recherche pour le developpement; A*MIDEX fundation "Pepiniere d'excellence" program ANR-10-EQPX-0024,ASTER-CEREGE,PLATEFORME DE GEOCHIMIE ISOTOPIQUE ASTER/CEREGE(2010) |
format |
Article in Journal/Newspaper |
author |
Rochette, P. Braucher, R. Folco, L. Horng, C.S. Aumaître, G. Bourles, D.L. Keddadouche, K. |
author_facet |
Rochette, P. Braucher, R. Folco, L. Horng, C.S. Aumaître, G. Bourles, D.L. Keddadouche, K. |
author_sort |
Rochette, P. |
title |
10Be in Australasian microtektites compared to tektites: Size and geographic controls |
title_short |
10Be in Australasian microtektites compared to tektites: Size and geographic controls |
title_full |
10Be in Australasian microtektites compared to tektites: Size and geographic controls |
title_fullStr |
10Be in Australasian microtektites compared to tektites: Size and geographic controls |
title_full_unstemmed |
10Be in Australasian microtektites compared to tektites: Size and geographic controls |
title_sort |
10be in australasian microtektites compared to tektites: size and geographic controls |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://hal.science/hal-01868053 https://doi.org/10.1130/G45038.1 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
ISSN: 0091-7613 EISSN: 1943-2682 Geology https://hal.science/hal-01868053 Geology, 2019, 46 (9), pp.803 - 806. ⟨10.1130/G45038.1⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1130/G45038.1 hal-01868053 https://hal.science/hal-01868053 doi:10.1130/G45038.1 PRODINRA: 450134 WOS: 000442904600019 |
op_doi |
https://doi.org/10.1130/G45038.1 |
container_title |
Geology |
container_volume |
46 |
container_issue |
9 |
container_start_page |
803 |
op_container_end_page |
806 |
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1802638116440244224 |