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A noble gas and cosmogenic radionuclide analysis of two ordinary chondrites from Almahata Sitta

Meier, Matthias LU ; Welten, Kees C.; Caffee, Marc W.; Friedrich, Jon M.; Jenniskens, Peter; Nishiizumi, Kunihiko; Shaddad, Muawia H. and Wieler, Rainer (2012) In Meteoritics and Planetary Science 47(6). p.1075-1086
Abstract
We present the results of a noble gas (He, Ne, Ar) and cosmogenic radionuclide (10Be, 26Al, 36Cl) analysis of two chondritic fragments (#A100, L4 and #25, H5) found in the Almahata Sitta strewn field in Sudan. We confirm their earlier attribution to the same fall as the ureilites dominating the strewn field, based on the following findings: (1) both chondrite samples indicate a preatmospheric radius of approximately 300 g cm-2, consistent with the preatmospheric size of asteroid 2008 TC3 that produced the Almahata Sitta strewn field; (2) both have, within error, a 21Ne/26Al-based cosmic ray exposure age of approximately 20 Ma, identical to the reported ages of Almahata Sitta ureilites; (3) both exhibit hints of ureilitic Ar in the trapped... (More)
We present the results of a noble gas (He, Ne, Ar) and cosmogenic radionuclide (10Be, 26Al, 36Cl) analysis of two chondritic fragments (#A100, L4 and #25, H5) found in the Almahata Sitta strewn field in Sudan. We confirm their earlier attribution to the same fall as the ureilites dominating the strewn field, based on the following findings: (1) both chondrite samples indicate a preatmospheric radius of approximately 300 g cm-2, consistent with the preatmospheric size of asteroid 2008 TC3 that produced the Almahata Sitta strewn field; (2) both have, within error, a 21Ne/26Al-based cosmic ray exposure age of approximately 20 Ma, identical to the reported ages of Almahata Sitta ureilites; (3) both exhibit hints of ureilitic Ar in the trapped component. We discuss a possible earlier irradiation phase for the two fragments of approximately 1020 Ma, visible only in cosmogenic 38Ar. We also discuss the approximately 3.8 Ga (4He) and approximately 4.6 Ga (40Ar) gas retention ages, measured in both chondritic fragments. These imply that the two chondrite fragments were incorporated into the ureilite host early in solar system evolution, and that the parent asteroid from which 2008 TC3 is derived has not experienced a large break-up event in the last 3.8 Ga. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Meteoritics and Planetary Science
volume
47
issue
6
pages
1075 - 1086
publisher
Wiley-Blackwell
external identifiers
  • wos:000306177400008
  • scopus:84863735678
ISSN
1086-9379
DOI
10.1111/j.1945-5100.2012.01379.x
language
English
LU publication?
yes
id
41f222ac-2f81-400f-a486-a75fe1663c93 (old id 3001248)
date added to LUP
2012-08-21 12:43:40
date last changed
2017-11-19 03:57:58
@article{41f222ac-2f81-400f-a486-a75fe1663c93,
  abstract     = {We present the results of a noble gas (He, Ne, Ar) and cosmogenic radionuclide (10Be, 26Al, 36Cl) analysis of two chondritic fragments (#A100, L4 and #25, H5) found in the Almahata Sitta strewn field in Sudan. We confirm their earlier attribution to the same fall as the ureilites dominating the strewn field, based on the following findings: (1) both chondrite samples indicate a preatmospheric radius of approximately 300 g cm-2, consistent with the preatmospheric size of asteroid 2008 TC3 that produced the Almahata Sitta strewn field; (2) both have, within error, a 21Ne/26Al-based cosmic ray exposure age of approximately 20 Ma, identical to the reported ages of Almahata Sitta ureilites; (3) both exhibit hints of ureilitic Ar in the trapped component. We discuss a possible earlier irradiation phase for the two fragments of approximately 1020 Ma, visible only in cosmogenic 38Ar. We also discuss the approximately 3.8 Ga (4He) and approximately 4.6 Ga (40Ar) gas retention ages, measured in both chondritic fragments. These imply that the two chondrite fragments were incorporated into the ureilite host early in solar system evolution, and that the parent asteroid from which 2008 TC3 is derived has not experienced a large break-up event in the last 3.8 Ga.},
  author       = {Meier, Matthias and Welten, Kees C. and Caffee, Marc W. and Friedrich, Jon M. and Jenniskens, Peter and Nishiizumi, Kunihiko and Shaddad, Muawia H. and Wieler, Rainer},
  issn         = {1086-9379},
  language     = {eng},
  number       = {6},
  pages        = {1075--1086},
  publisher    = {Wiley-Blackwell},
  series       = {Meteoritics and Planetary Science},
  title        = {A noble gas and cosmogenic radionuclide analysis of two ordinary chondrites from Almahata Sitta},
  url          = {http://dx.doi.org/10.1111/j.1945-5100.2012.01379.x},
  volume       = {47},
  year         = {2012},
}