The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation
The early stages of atmospheric entry are investigated in four large (250–950 μm) unmelted micrometeorites (three fine‐grained and one composite), derived from the Transantarctic Mountain micrometeorite collection. These particles have abundant, interconnected, secondary pore spaces which form branc...
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Online Access: | http://hdl.handle.net/10044/1/66180 https://doi.org/10.1111/maps.13220 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/66180 2023-05-15T14:01:35+02:00 The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation Suttle, M Genge, M Folco, L Van Ginneken, M Lin, Q Russell, S Najorka, S Science and Technology Facilities Council (STFC) Science and Technology Facilities Council (STFC) 2018-11-01 http://hdl.handle.net/10044/1/66180 https://doi.org/10.1111/maps.13220 unknown Wiley Meteoritics and Planetary Science 1086-9379 http://hdl.handle.net/10044/1/66180 https://dx.doi.org/10.1111/maps.13220 ST/M003167/1 ST/N000803/1 © The Meteoritical Society, 2018. This is the accepted version of the following article, which has been published in final form at https://onlinelibrary.wiley.com/doi/full/10.1111/maps.13220 520 503 Science & Technology Physical Sciences Geochemistry & Geophysics ANTARCTIC MICROMETEORITES COSMIC SPHERULES ACCRETION RATE DUST QUANTIFICATION MINERALOGY METEORITE POROSITY PHYLLOSILICATES TEMPERATURES 0201 Astronomical and Space Sciences 0402 Geochemistry 0403 Geology Journal Article 2018 ftimperialcol https://doi.org/10.1111/maps.13220 2019-12-05T23:37:56Z The early stages of atmospheric entry are investigated in four large (250–950 μm) unmelted micrometeorites (three fine‐grained and one composite), derived from the Transantarctic Mountain micrometeorite collection. These particles have abundant, interconnected, secondary pore spaces which form branching channels and show evidence of enhanced heating along their channel walls. Additionally, a micrometeorite with a double‐walled igneous rim is described, suggesting that some particles undergo volume expansion during entry. This study provides new textural data which links together entry heating processes known to operate inside micrometeoroids, thereby generating a more comprehensive model of their petrographic evolution. Initially, flash heated micrometeorites develop a melt layer on their exterior; this igneous rim migrates inwards. Meanwhile, the particle core is heated by the decomposition of low‐temperature phases and by volatile gas release. Where the igneous rim acts as a seal, gas pressures rise, resulting in the formation of interconnected voids and higher particle porosities. Eventually, the igneous rim is breached and gas exchange with the atmosphere occurs. This mechanism replaces inefficient conductive rim‐to‐core thermal gradients with more efficient particle‐wide heating, driven by convective gas flow. Interconnected voids also increase the likelihood of particle fragmentation during entry and, may therefore explain the rarity of large fine‐grained micrometeorites among collections. Article in Journal/Newspaper Antarc* Antarctic Imperial College London: Spiral Antarctic Meteoritics & Planetary Science 54 3 503 520 |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
unknown |
topic |
Science & Technology Physical Sciences Geochemistry & Geophysics ANTARCTIC MICROMETEORITES COSMIC SPHERULES ACCRETION RATE DUST QUANTIFICATION MINERALOGY METEORITE POROSITY PHYLLOSILICATES TEMPERATURES 0201 Astronomical and Space Sciences 0402 Geochemistry 0403 Geology |
spellingShingle |
Science & Technology Physical Sciences Geochemistry & Geophysics ANTARCTIC MICROMETEORITES COSMIC SPHERULES ACCRETION RATE DUST QUANTIFICATION MINERALOGY METEORITE POROSITY PHYLLOSILICATES TEMPERATURES 0201 Astronomical and Space Sciences 0402 Geochemistry 0403 Geology Suttle, M Genge, M Folco, L Van Ginneken, M Lin, Q Russell, S Najorka, S The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation |
topic_facet |
Science & Technology Physical Sciences Geochemistry & Geophysics ANTARCTIC MICROMETEORITES COSMIC SPHERULES ACCRETION RATE DUST QUANTIFICATION MINERALOGY METEORITE POROSITY PHYLLOSILICATES TEMPERATURES 0201 Astronomical and Space Sciences 0402 Geochemistry 0403 Geology |
description |
The early stages of atmospheric entry are investigated in four large (250–950 μm) unmelted micrometeorites (three fine‐grained and one composite), derived from the Transantarctic Mountain micrometeorite collection. These particles have abundant, interconnected, secondary pore spaces which form branching channels and show evidence of enhanced heating along their channel walls. Additionally, a micrometeorite with a double‐walled igneous rim is described, suggesting that some particles undergo volume expansion during entry. This study provides new textural data which links together entry heating processes known to operate inside micrometeoroids, thereby generating a more comprehensive model of their petrographic evolution. Initially, flash heated micrometeorites develop a melt layer on their exterior; this igneous rim migrates inwards. Meanwhile, the particle core is heated by the decomposition of low‐temperature phases and by volatile gas release. Where the igneous rim acts as a seal, gas pressures rise, resulting in the formation of interconnected voids and higher particle porosities. Eventually, the igneous rim is breached and gas exchange with the atmosphere occurs. This mechanism replaces inefficient conductive rim‐to‐core thermal gradients with more efficient particle‐wide heating, driven by convective gas flow. Interconnected voids also increase the likelihood of particle fragmentation during entry and, may therefore explain the rarity of large fine‐grained micrometeorites among collections. |
author2 |
Science and Technology Facilities Council (STFC) Science and Technology Facilities Council (STFC) |
format |
Article in Journal/Newspaper |
author |
Suttle, M Genge, M Folco, L Van Ginneken, M Lin, Q Russell, S Najorka, S |
author_facet |
Suttle, M Genge, M Folco, L Van Ginneken, M Lin, Q Russell, S Najorka, S |
author_sort |
Suttle, M |
title |
The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation |
title_short |
The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation |
title_full |
The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation |
title_fullStr |
The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation |
title_full_unstemmed |
The atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation |
title_sort |
atmospheric entry of fine-grained micrometeorites: the role of volatile gases in heating and fragmentation |
publisher |
Wiley |
publishDate |
2018 |
url |
http://hdl.handle.net/10044/1/66180 https://doi.org/10.1111/maps.13220 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
520 503 |
op_relation |
Meteoritics and Planetary Science 1086-9379 http://hdl.handle.net/10044/1/66180 https://dx.doi.org/10.1111/maps.13220 ST/M003167/1 ST/N000803/1 |
op_rights |
© The Meteoritical Society, 2018. This is the accepted version of the following article, which has been published in final form at https://onlinelibrary.wiley.com/doi/full/10.1111/maps.13220 |
op_doi |
https://doi.org/10.1111/maps.13220 |
container_title |
Meteoritics & Planetary Science |
container_volume |
54 |
container_issue |
3 |
container_start_page |
503 |
op_container_end_page |
520 |
_version_ |
1766271516063825920 |