Hydrous olivine alteration on Mars and Earth

Author
Váci, Zoltán
Agee, Carl B.
Herd, Christopher
Walton, Erin L.
Tschauner, Oliver
Ziegler, Karen
Prakapenka, Vitali B.
Greenberg, Eran
Monique-Thomas, Sylvia
Faculty Advisor
Date
2020
Keywords
olivines , Mars
Abstract (summary)
Hydrous alteration of olivine macrocrysts in a Martian olivine phyric basalt, NWA 10416, and a terrestrial basalt from southern Colorado are examined using SEM, EPMA, TEM, and µXRD techniques. The olivines in the meteorite contain linear nanotubes of hydrous material, amorphous areas, and fluid dissolution textures quite distinct from alteration identified in other Martian meteorites. Instead, they bear resemblance to terrestrial deuteric alteration features. The presence of the hydrous alteration phase Mg-laihunite within the olivines has been confirmed by µXRD analysis. The cores of the olivines in both Martian and terrestrial samples are overgrown by unaltered rims whose compositions match those of a separate population of groundmass olivines, suggesting that the core olivines are xenocrysts whose alteration preceded crystallization of the groundmass. The terrestrial sample is linked to deep crustal metasomatism and the “ignimbrite flare-up” of the Oligocene epoch. The comparison of the two samples suggests the existence of an analogous relatively water-rich magmatic reservoir on Mars.
Publication Information
Vaci Z., Herd C., Walton E., Tschauner O., Ziegler K., Prakapenka V., Greenberg E. and Thomas S.-M. (2020). Hydrous olivine alteration on Mars. Meteoritics & Planetary Science 5:1011-1030. DOI: 10.1111/maps.13479
DOI
Notes
Item Type
Article
Language
English
Rights
All Rights Reserved