Loading...
The Fe/S ratio of pyrrhotite group sulfides in chondrites: An indicator of oxidation and implications for return samples from asteroids Ryugu and Bennu
Schrader, Devin L Davidson, Jemma McCoy, Timothy J Zega, Thomas J Domanik, Kenneth J
Schrader, Devin L
Davidson, Jemma
McCoy, Timothy J
Zega, Thomas J
Domanik, Kenneth J
Citations
Altmetric:
Advisors
Editors
Other Contributors
Affiliation
EPub Date
Issue Date
2021-03-26
Submitted Date
2020-12-08
Subject Terms
Sulfide
Pyrrhotite
Troilite
Pyrite
Chondrite
Oxidation
Asteroid sample return
Pyrrhotite
Troilite
Pyrite
Chondrite
Oxidation
Asteroid sample return
Collections
Files
Loading...
Published version
Adobe PDF, 3.3 MB
Research Projects
Organizational Units
Journal Issue
Other Titles
Abstract
Determining compositional trends among individual minerals is key to understanding the thermodynamic conditions under which they formed and altered, and is also essential to maximizing the scientific value of small extraterrestrial samples, including returned samples and meteorites. Here we report the chemical compositions of Fe-sulfides, focusing on the pyrrhotite-group sulfides, which are ubiquitous in chondrites and are sensitive indicators of formation and alteration conditions in the protoplanetary disk and in small Solar System bodies. Our data show that while there are trends with the at.% Fe/S ratio of pyrrhotite with thermal and aqueous alteration in some meteorite groups, there is a universal trend between the Fe/S ratio and degree of oxidation. Relatively reducing conditions led to the formation of troilite during: (1) chondrule formation in the protoplanetary disk (i.e., pristine chondrites) and (2) parent body thermal alteration (i.e., LL4 to LL6, CR1, CM, and CY chondrites). Oxidizing and sulfidizing conditions led to the formation of Fe-depleted pyrrhotite with low Fe/S ratios during: (1) aqueous alteration (i.e., CM and CI chondrites), and (2) thermal alteration (i.e., CK and R chondrites). The presence of troilite in highly aqueously altered carbonaceous chondrites (e.g., CY, CR1, and some CM chondrites) indicates they were heated after aqueous alteration. The presence of troilite, Fe-depleted pyrrhotite, or pyrite in a chondrite can provide an estimate of the oxygen and sulfur fugacities at which it was formed or altered. The data reported here can be used to estimate the oxygen fugacity of formation and potentially the aqueous and/or thermal histories of sulfides in extraterrestrial samples, including those returned by the Hayabusa2 mission and due to be returned by the OSIRIS-REx mission in the near future.
Citation
Devin L. Schrader, Jemma Davidson, Timothy J. McCoy, Thomas J. Zega, Sara S. Russell, Kenneth J. Domanik, Ashley J. King, The Fe/S ratio of pyrrhotite group sulfides in chondrites: An indicator of oxidation and implications for return samples from asteroids Ryugu and Bennu, Geochimica et Cosmochimica Acta, Volume 303, 2021, Pages 66-91, ISSN 0016-7037, https://doi.org/10.1016/j.gca.2021.03.019.
Publisher
Journal
Research Unit
PubMed ID
PubMed Central ID
Embedded videos
Type
Journal Article
Item Description
Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). The attached file is the published version of the article.
NHM Repository
NHM Repository
Series/Report no.
ISSN
0016-7037
EISSN
1872-9533
ISBN
ISMN
GovDoc
Test Link
License
openAccess