The effects of highly reduced magmatism revealed through aubrites
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Final Accepted Manuscript
Author
Wilbur, Zoë E.Udry, Arya
McCubbin, Francis M.
vander Kaaden, Kathleen E.
DeFelice, Christopher
Ziegler, Karen
Ross, Daniel Kent
McCoy, Timothy J.
Gross, Juliane
Barnes, Jessica J.
Dygert, Nick
Zeigler, Ryan A.
Turrin, Brent D.
McCoy, Christopher
Affiliation
Lunar and Planetary Laboratory, University of ArizonaIssue Date
2022-05-14
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Show full item recordPublisher
WileyCitation
Wilbur, Z. E., Udry, A., McCubbin, F. M., vander Kaaden, K. E., DeFelice, C., Ziegler, K., Ross, D. K., McCoy, T. J., Gross, J., Barnes, J. J., Dygert, N., Zeigler, R. A., Turrin, B. D., & McCoy, C. (2022). The effects of highly reduced magmatism revealed through aubrites. Meteoritics and Planetary Science.Rights
© 2022 The Meteoritical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Enstatite-rich meteorites, including the aubrites, formed under conditions of very low oxygen fugacity (ƒO2: iron-wüstite buffer −2 to −6) and thus offer the ability to study reduced magmatism present on multiple bodies in our solar system. Elemental partitioning among metals, sulfides, and silicates is poorly constrained at low ƒO2; however, studies of enstatite-rich meteorites may yield empirical evidence of the effects of low ƒO2 on elemental behavior. This work presents comprehensive petrologic and oxygen isotopic studies of 14 aubrites, including four meteorites that have not been previously investigated in detail. The aubrites exhibit a variety of textures and mineralogy, and their elemental zoning patterns point to slow cooling histories for all 14 samples. Oxygen isotope analyses suggest that the aubrite parent bodies may be more heterogeneous than originally reported or may have experienced incomplete magmatic differentiation. Contrary to the other classified aubrites and based on textural and mineralogical observations, we suggest that the Northwest Africa 8396 meteorite shows an affinity for an enstatite chondrite parentage. By measuring major elemental compositions of silicates, sulfides, and metals, we calculate new metal–silicate, sulfide–silicate, and sulfide–metal partition coefficients for aubrites that are applicable to igneous systems at low ƒO2. The geochemical behavior of elements in aubrites, as determined using partition coefficients, is similar to the geochemical behavior of elements determined experimentally for magmatic systems on Mercury. Enstatite-rich meteorites, including aubrites, represent valuable natural petrologic analogues to Mercury and their study could further our understanding of reduced magmatism in our solar system.Note
12 month embargo; first published: 14 May 2022ISSN
1086-9379EISSN
1945-5100Version
Final accepted manuscriptae974a485f413a2113503eed53cd6c53
10.1111/maps.13823