Magnetite in Comet Wild 2: Evidence for parent body aqueous alteration

Hicks, L. J. and MacArthur, J. L. and Bridges, J. C. and Price, M. C. and Wickham-Eade, J. E. and Burchell, M. J. and Hansford, G. M. and Butterworth, A. L. and Gurman, S. J. and Baker, S. H. (2017) Magnetite in Comet Wild 2: Evidence for parent body aqueous alteration. Meteoritics & Planetary Science, 52 (10). pp. 2075-2096. ISSN 1086-9379. (doi:https://doi.org/10.1111/maps.12909) (Full text available)

PDF - Publisher pdf

Creative Commons Licence
This work is licensed under a Creative Commons Attribution 4.0 International License.
Download (786kB) Preview
[img]
Preview
Official URL
https://doi.org/10.1111/maps.12909

Abstract

The mineralogy of comet 81P/Wild 2 particles, collected in aerogel by the Stardust mission, has been determined using synchrotron Fe-K X-ray absorption spectroscopy with insitu transmission XRD and X-ray fluorescence, plus complementary microRaman analyses. Our investigation focuses on the terminal grains of eight Stardust tracks: C2112,4,170,0,0; C2045,2,176,0,0; C2045,3,177,0,0; C2045,4,178,0,0; C2065,4,187,0,0; C2098,4,188,0,0; C2119,4,189,0,0; and C2119,5,190,0,0. Three terminal grains have been identified as near pure magnetite Fe3O4. The presence of magnetite shows affinities between the Wild 2 mineral assemblage and carbonaceous chondrites, and probably resulted from hydrothermal alteration of the coexisting FeNi and ferromagnesian silicates in the cometary parent body. In order to further explore this hypothesis, powdered material from a CR2 meteorite (NWA 10256) was shot into the aerogel at 6.1kms(-1), using a light-gas gun, and keystones were then prepared in the same way as the Stardust keystones. Using similar analysis techniques to the eight Stardust tracks, a CR2 magnetite terminal grain establishes the likelihood of preserving magnetite during capture in silica aerogel

Item Type: Article
Subjects: Q Science
Q Science > QB Astronomy
Q Science > QB Astronomy > QB651 Planets, Minor
Divisions: Faculties > Sciences > School of Physical Sciences
Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Mark Burchell
Date Deposited: 30 Apr 2018 12:42 UTC
Last Modified: 18 May 2018 09:28 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/66873 (The current URI for this page, for reference purposes)
  • Depositors only (login required):

Downloads

Downloads per month over past year