Petrogenetic relationship between Allan Hills 77005 and other achondrites

Allan Hills (ALHA) 77005 is a newly discovered, unique achondrite from Antarctica. Petrologic similarities with the shergottites in terms of mineralogy, oxidation state, inferred source region composition, shock metamorphic effects and shock ages suggest a genetic relationship. Volatile to involatil...

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Bibliographic Details
Published in:Earth and Planetary Science Letters
Main Authors: McSween, Harry Y., Jr., Stolper, Edward M., Taylor, Lawrence A., Muntean, Richard A., O'Kelley, G. Davis, Eldridge, James S., Biswas, Swarajranjan, Ngo, Hung T., Lipschutz, Michael S.
Format: Article in Journal/Newspaper
Language:unknown
Published: Elsevier 1979
Subjects:
Allan Hills
Antarc*
Antarctica
Online Access:https://authors.library.caltech.edu/33404/
https://resolver.caltech.edu/CaltechAUTHORS:20120821-114725520
Description
Summary:Allan Hills (ALHA) 77005 is a newly discovered, unique achondrite from Antarctica. Petrologic similarities with the shergottites in terms of mineralogy, oxidation state, inferred source region composition, shock metamorphic effects and shock ages suggest a genetic relationship. Volatile to involatile element ratios (e.g. K/U, Rb/U, Cs/U, Tl/U) and abundances of other trace elements support this hypothesis. ALHA 77005 may be a cumulate that crystallized from a liquid parental to those from which the shergottites crystallized; alternatively it may be a sample of the type of source peridotite from which shergottite parent liquids were derived by partial melting. Chemical similarities with terrestrial ultramafic rocks suggest that this unique meteorite provides an additional sample of the only other solar system body known to have basalt source regions chemically similar to the upper mantle of the Earth.

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