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Condensation and fractionation of rare earths in the solar nebulaThe condensation behavior of the rare earth elements in the solar nebula is calculated on the basis of the most recent thermodynamic data in order to construct a model explaining group II rare earth element patterns in Allende inclusions. Models considered all involve the removal of large fractions of the more refractory heavy rare earth elements in an early condensate, followed by the condensation of the remainder at a lower temperature. It is shown that the model of Boynton (1975) in which one rare earth element component is dissolved nonideally in perovskite according to relative activity coefficients can not reasonably be made to fit the observed group II patterns. A model in which two rare earth components control the patterns and dissolve ideally in perovskite is proposed and shown to be able to account for the 20 patterns by variations of the perovskite removal temperature and the relative proportions of the two components.
Document ID
19790068686
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Davis, A. M.
(Chicago Univ. Chicago, IL, United States)
Grossman, L.
(Chicago, University Chicago, Ill., United States)
Date Acquired
August 9, 2013
Publication Date
October 1, 1979
Publication Information
Publication: Geochimica et Cosmochimica Acta
Volume: 43
Subject Category
Lunar And Planetary Exploration
Accession Number
79A52699
Funding Number(s)
CONTRACT_GRANT: NGR-14-001-249
Distribution Limits
Public
Copyright
Other

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