Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well
Ten glass cosmic spherules (CS) from the South Pole water well collection were analyzed by electron microprobe. Nine of them have Fe/Mn and Fe/Mg ratios in the range typical of chondrites. One of them (SP37-3), along with up to six other previously analyzed CS, have nonchondritic Fe/Mn and Fe/Mg rat...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Meteoritics & Planetary Science Archives
2007
|
Subjects: | |
Online Access: | https://journals.uair.arizona.edu/index.php/maps/article/view/15389 |
id |
ftunivarizonaojs:oai:journals.uair.arizona.edu:article/15389 |
---|---|
record_format |
openpolar |
spelling |
ftunivarizonaojs:oai:journals.uair.arizona.edu:article/15389 2023-05-15T18:21:54+02:00 Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well Taylor, Susan Herzog, Gregory F. Delaney, Jeremy S. 2007-01-01 application/pdf https://journals.uair.arizona.edu/index.php/maps/article/view/15389 eng eng Meteoritics & Planetary Science Archives https://journals.uair.arizona.edu/index.php/maps/article/view/15389/15377 https://journals.uair.arizona.edu/index.php/maps/article/view/15389 Meteoritics & Planetary Science Archives; Vol 42, No 2 (2007); 223-233 1945-5100 1086-9379 Micrometeorites;Composition;HED meteorites info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article 2007 ftunivarizonaojs 2020-11-14T17:53:01Z Ten glass cosmic spherules (CS) from the South Pole water well collection were analyzed by electron microprobe. Nine of them have Fe/Mn and Fe/Mg ratios in the range typical of chondrites. One of them (SP37-3), along with up to six other previously analyzed CS, have nonchondritic Fe/Mn and Fe/Mg ratios that agree well with values typical of either (basaltic) howardite, eucrite, and diogenite (HED) meteorites or Martian basalts, but not of lunar samples. SP37-3 also contains an anorthite relic grain. Anorthite has not previously been reported in cosmic spherules, but is well known in HED meteorites. The much greater frequency of HEDs among hand-sized meteorites suggests but does not prove that HED precursors are more likely for the nonchondritic spherules.We estimate that HED-like micrometeorites constitute 0.5 0.4% of the total population of micrometeorites in the South Pole water well, a fraction that translates to a flux of 1.6 0.3 x 10^(-8) g HED micrometeorites/m^2-y. The ratio of HED-like objects to carbonaceous objects is about 100 times less in micrometeorites than among hand-size specimens. We infer that the comparative mechanical weakness of carbonaceous precursor materials tends to encourage spherule formation. Article in Journal/Newspaper South pole Journals at the University of Arizona South Pole |
institution |
Open Polar |
collection |
Journals at the University of Arizona |
op_collection_id |
ftunivarizonaojs |
language |
English |
topic |
Micrometeorites;Composition;HED meteorites |
spellingShingle |
Micrometeorites;Composition;HED meteorites Taylor, Susan Herzog, Gregory F. Delaney, Jeremy S. Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well |
topic_facet |
Micrometeorites;Composition;HED meteorites |
description |
Ten glass cosmic spherules (CS) from the South Pole water well collection were analyzed by electron microprobe. Nine of them have Fe/Mn and Fe/Mg ratios in the range typical of chondrites. One of them (SP37-3), along with up to six other previously analyzed CS, have nonchondritic Fe/Mn and Fe/Mg ratios that agree well with values typical of either (basaltic) howardite, eucrite, and diogenite (HED) meteorites or Martian basalts, but not of lunar samples. SP37-3 also contains an anorthite relic grain. Anorthite has not previously been reported in cosmic spherules, but is well known in HED meteorites. The much greater frequency of HEDs among hand-sized meteorites suggests but does not prove that HED precursors are more likely for the nonchondritic spherules.We estimate that HED-like micrometeorites constitute 0.5 0.4% of the total population of micrometeorites in the South Pole water well, a fraction that translates to a flux of 1.6 0.3 x 10^(-8) g HED micrometeorites/m^2-y. The ratio of HED-like objects to carbonaceous objects is about 100 times less in micrometeorites than among hand-size specimens. We infer that the comparative mechanical weakness of carbonaceous precursor materials tends to encourage spherule formation. |
format |
Article in Journal/Newspaper |
author |
Taylor, Susan Herzog, Gregory F. Delaney, Jeremy S. |
author_facet |
Taylor, Susan Herzog, Gregory F. Delaney, Jeremy S. |
author_sort |
Taylor, Susan |
title |
Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well |
title_short |
Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well |
title_full |
Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well |
title_fullStr |
Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well |
title_full_unstemmed |
Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well |
title_sort |
crumbs from the crust of vesta: achondritic cosmic spherules from the south pole water well |
publisher |
Meteoritics & Planetary Science Archives |
publishDate |
2007 |
url |
https://journals.uair.arizona.edu/index.php/maps/article/view/15389 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
Meteoritics & Planetary Science Archives; Vol 42, No 2 (2007); 223-233 1945-5100 1086-9379 |
op_relation |
https://journals.uair.arizona.edu/index.php/maps/article/view/15389/15377 https://journals.uair.arizona.edu/index.php/maps/article/view/15389 |
_version_ |
1766201230407761920 |