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Chemical and isotopic fractionation by grain size separatesFractionation of refractory elements according to grain size is argued to occur during their growth. Two major modes should exist: (1) during thermal condensation sequences whenever the condensing phase (e.g. Mg2SiO4) does not alloy with the precondensed phase (e.g. MgAl2O4); (2) during accretion of gaseous atoms in the nonequilibrated interstellar medium. Processes dynamically sorting grains according to size (e.g. sedimentation) therefore are potentially capable of achieving fractionations normally attributed to separations of dust and gas. This paper considers the first mode during supernova condensation; however, it also can occur in an equilibrium solar condensation sequence owing to an overlooked freedom in that simplified description.
Document ID
19800069549
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Clayton, D. D.
Date Acquired
August 10, 2013
Publication Date
April 1, 1980
Publication Information
Publication: Earth and Planetary Science Letters
Volume: 47
Issue: 2, Ap
Subject Category
Lunar And Planetary Exploration
Accession Number
80A53719
Funding Number(s)
CONTRACT_GRANT: NSG-7361
Distribution Limits
Public
Copyright
Other

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