Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites.
The δ18O, δ17O, δ13C, and δ14C compositions of carbonate grains were measured from paired Antarctic CM2 chondrites (EET96006, EET96016, EET96017, and EET96019). Oxygen isotopic compositions reveal both terrestrial and extraterrestrial carbonate sources. Bulk δ13C and δ14C measurements suggest at lea...
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ftunivmaryland:oai:drum.lib.umd.edu:1903/2672 2023-05-15T13:38:51+02:00 Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites. Tyra, Mark Anthony Farquhar, James Digital Repository at the University of Maryland University of Maryland (College Park, Md.) Geology 2005-06-01 6612264 bytes application/pdf http://hdl.handle.net/1903/2672 en_US eng http://hdl.handle.net/1903/2672 Geochemistry Geology Chemistry Physical Antarctic meteorites CM carbonate weathering C-14 isotope geochemistry Thesis 2005 ftunivmaryland 2022-11-11T11:11:51Z The δ18O, δ17O, δ13C, and δ14C compositions of carbonate grains were measured from paired Antarctic CM2 chondrites (EET96006, EET96016, EET96017, and EET96019). Oxygen isotopic compositions reveal both terrestrial and extraterrestrial carbonate sources. Bulk δ13C and δ14C measurements suggest at least two terrestrial carbonate components: 1) carbonate derived from equilibration of atmospheric CO2 with silicates during weathering reactions, and 2) carbonate derived from a second undefined source. Oxygen and carbon isotope data suggest that silicate weathering reactions drove oxygen isotopic composition of Antarctic water away from the terrestrial fractionation line (TFL) (D17O < 3.6). Further oxygen isotopic compositional constraints were placed by Secondary Ionization Mass Spectrometry (SIMS) of in-situ carbonates. We suggest three sources for meteoritic carbonate: 1) primary calcite formed in the presence of evolving planetesimal water and 2) secondary calcite derived from alkalinity laden terrestrial water and 3) alkalinity formed as the result of weathering of meteoritic silicates. Thesis Antarc* Antarctic University of Maryland: Digital Repository (DRUM) Antarctic |
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Open Polar |
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University of Maryland: Digital Repository (DRUM) |
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ftunivmaryland |
language |
English |
topic |
Geochemistry Geology Chemistry Physical Antarctic meteorites CM carbonate weathering C-14 isotope geochemistry |
spellingShingle |
Geochemistry Geology Chemistry Physical Antarctic meteorites CM carbonate weathering C-14 isotope geochemistry Tyra, Mark Anthony Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites. |
topic_facet |
Geochemistry Geology Chemistry Physical Antarctic meteorites CM carbonate weathering C-14 isotope geochemistry |
description |
The δ18O, δ17O, δ13C, and δ14C compositions of carbonate grains were measured from paired Antarctic CM2 chondrites (EET96006, EET96016, EET96017, and EET96019). Oxygen isotopic compositions reveal both terrestrial and extraterrestrial carbonate sources. Bulk δ13C and δ14C measurements suggest at least two terrestrial carbonate components: 1) carbonate derived from equilibration of atmospheric CO2 with silicates during weathering reactions, and 2) carbonate derived from a second undefined source. Oxygen and carbon isotope data suggest that silicate weathering reactions drove oxygen isotopic composition of Antarctic water away from the terrestrial fractionation line (TFL) (D17O < 3.6). Further oxygen isotopic compositional constraints were placed by Secondary Ionization Mass Spectrometry (SIMS) of in-situ carbonates. We suggest three sources for meteoritic carbonate: 1) primary calcite formed in the presence of evolving planetesimal water and 2) secondary calcite derived from alkalinity laden terrestrial water and 3) alkalinity formed as the result of weathering of meteoritic silicates. |
author2 |
Farquhar, James Digital Repository at the University of Maryland University of Maryland (College Park, Md.) Geology |
format |
Thesis |
author |
Tyra, Mark Anthony |
author_facet |
Tyra, Mark Anthony |
author_sort |
Tyra, Mark Anthony |
title |
Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites. |
title_short |
Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites. |
title_full |
Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites. |
title_fullStr |
Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites. |
title_full_unstemmed |
Terrestrial Alteration of CM2 Chondritic Carbonates in a Suite of Paired Antarctic Meteorites. |
title_sort |
terrestrial alteration of cm2 chondritic carbonates in a suite of paired antarctic meteorites. |
publishDate |
2005 |
url |
http://hdl.handle.net/1903/2672 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/1903/2672 |
_version_ |
1766111649286062080 |