Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages
Abstract– The interior texture and chemical and noble gas composition of 99 cosmic spherules collected from the meteorite ice field around the Yamato Mountains in Antarctica were investigated. Their textures were used to classify the spherules into six different types reflecting the degree of heatin...
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crwiley:10.1111/j.1945-5100.2010.01093.x 2023-12-03T10:12:46+01:00 Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages OSAWA, Takahito YAMAMOTO, Yukio NOGUCHI, Takaaki IOSE, Akari NAGAO, Keisuke 2010 http://dx.doi.org/10.1111/j.1945-5100.2010.01093.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1945-5100.2010.01093.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1945-5100.2010.01093.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Meteoritics & Planetary Science volume 45, issue 8, page 1320-1339 ISSN 1086-9379 1945-5100 Space and Planetary Science Geophysics journal-article 2010 crwiley https://doi.org/10.1111/j.1945-5100.2010.01093.x 2023-11-09T14:00:01Z Abstract– The interior texture and chemical and noble gas composition of 99 cosmic spherules collected from the meteorite ice field around the Yamato Mountains in Antarctica were investigated. Their textures were used to classify the spherules into six different types reflecting the degree of heating: 13 were cryptocrystalline, 40 were barred olivine, 3 were porphyritic A, 24 were porphyritic B, 9 were porphyritic C, and 10 were partially melted spherules. While a correlation exists between the type of spherule and its noble gas content, there is no significant correlation between its chemical composition and noble gas content. Fifteen of the spherules still had detectable amounts of extraterrestrial He, and the majority of them had 3 He/ 4 He ratios that were close to that of solar wind (SW). The Ne isotopic composition of 28 of the spherules clustered between implantation‐fractionated SW and air. Extraterrestrial Ar, confirmed to be present because it had a 40 Ar/ 36 Ar ratio lower than that of terrestrial atmosphere, was found in 35 of the spherules. An enigmatic spherule, labeled M240410, had an extremely high concentration of cosmogenic nuclides. Assuming 4π exposure to galactic and solar cosmic rays as a micrometeoroid and no exposure on the parent body, the cosmic‐ray exposure (CRE) age of 393 Myr could be computed using cosmogenic 21 Ne. Under these model assumptions, the inferred age suggests that the particle might have been an Edgeworth‐Kuiper Belt object. Alternatively, if exposure near the surface of its parent body was dominant, the CRE age of 382 Myr can be estimated from the cosmogenic 38 Ar using the production rate of the 2π exposure geometry, and implies that the particle may have originated in the mature regolith of an asteroid. Article in Journal/Newspaper Antarc* Antarctic Antarctica Wiley Online Library (via Crossref) Antarctic Yamato ENVELOPE(35.583,35.583,-71.417,-71.417) Meteoritics & Planetary Science 45 8 1320 1339 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Space and Planetary Science Geophysics |
spellingShingle |
Space and Planetary Science Geophysics OSAWA, Takahito YAMAMOTO, Yukio NOGUCHI, Takaaki IOSE, Akari NAGAO, Keisuke Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages |
topic_facet |
Space and Planetary Science Geophysics |
description |
Abstract– The interior texture and chemical and noble gas composition of 99 cosmic spherules collected from the meteorite ice field around the Yamato Mountains in Antarctica were investigated. Their textures were used to classify the spherules into six different types reflecting the degree of heating: 13 were cryptocrystalline, 40 were barred olivine, 3 were porphyritic A, 24 were porphyritic B, 9 were porphyritic C, and 10 were partially melted spherules. While a correlation exists between the type of spherule and its noble gas content, there is no significant correlation between its chemical composition and noble gas content. Fifteen of the spherules still had detectable amounts of extraterrestrial He, and the majority of them had 3 He/ 4 He ratios that were close to that of solar wind (SW). The Ne isotopic composition of 28 of the spherules clustered between implantation‐fractionated SW and air. Extraterrestrial Ar, confirmed to be present because it had a 40 Ar/ 36 Ar ratio lower than that of terrestrial atmosphere, was found in 35 of the spherules. An enigmatic spherule, labeled M240410, had an extremely high concentration of cosmogenic nuclides. Assuming 4π exposure to galactic and solar cosmic rays as a micrometeoroid and no exposure on the parent body, the cosmic‐ray exposure (CRE) age of 393 Myr could be computed using cosmogenic 21 Ne. Under these model assumptions, the inferred age suggests that the particle might have been an Edgeworth‐Kuiper Belt object. Alternatively, if exposure near the surface of its parent body was dominant, the CRE age of 382 Myr can be estimated from the cosmogenic 38 Ar using the production rate of the 2π exposure geometry, and implies that the particle may have originated in the mature regolith of an asteroid. |
format |
Article in Journal/Newspaper |
author |
OSAWA, Takahito YAMAMOTO, Yukio NOGUCHI, Takaaki IOSE, Akari NAGAO, Keisuke |
author_facet |
OSAWA, Takahito YAMAMOTO, Yukio NOGUCHI, Takaaki IOSE, Akari NAGAO, Keisuke |
author_sort |
OSAWA, Takahito |
title |
Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages |
title_short |
Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages |
title_full |
Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages |
title_fullStr |
Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages |
title_full_unstemmed |
Interior textures, chemical compositions, and noble gas signatures of Antarctic cosmic spherules: Possible sources of spherules with long exposure ages |
title_sort |
interior textures, chemical compositions, and noble gas signatures of antarctic cosmic spherules: possible sources of spherules with long exposure ages |
publisher |
Wiley |
publishDate |
2010 |
url |
http://dx.doi.org/10.1111/j.1945-5100.2010.01093.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1945-5100.2010.01093.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1945-5100.2010.01093.x |
long_lat |
ENVELOPE(35.583,35.583,-71.417,-71.417) |
geographic |
Antarctic Yamato |
geographic_facet |
Antarctic Yamato |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Meteoritics & Planetary Science volume 45, issue 8, page 1320-1339 ISSN 1086-9379 1945-5100 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1945-5100.2010.01093.x |
container_title |
Meteoritics & Planetary Science |
container_volume |
45 |
container_issue |
8 |
container_start_page |
1320 |
op_container_end_page |
1339 |
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1784259372503793664 |