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Analytical electron microscope study of eight ataxitesOptical and electron optical (SEM, TEM, AEM) techniques were employed to investigate the fine structure of eight ataxite-iron meteorites. Structural studies indicated that the ataxites can be divided into two groups: a Widmanstaetten decomposition group and a martensite decomposition group. The Widmanstaetten decomposition group has a Type I plessite microstructure and the central taenite regions contain highly dislocated lath martensite. The steep M shaped Ni gradients in the taenite are consistent with the fast cooling rates, of not less than 500 C/my, observed for this group. The martensite decomposition group has a Type III plessite microstructure and contains all the chemical group IVB ataxites. The maximum taenite Ni contents vary from 47.5 to 52.7 wt % and are consistent with slow cooling to low temperatures of not greater than 350 C at cooling rates of not greater than 25 C/my.
Document ID
19830040112
Document Type
Reprint (Version printed in journal)
Authors
Novotny, P. M. (Lehigh Univ. Bethlehem, PA, United States)
Goldstein, J. I. (Lehigh Univ. Bethlehem, PA, United States)
Williams, D. B. (Lehigh University Bethlehem, PA, United States)
Date Acquired
August 11, 2013
Publication Date
December 1, 1982
Publication Information
Publication: Geochimica et Cosmochimica Acta
Volume: 46
Subject Category
LUNAR AND PLANETARY EXPLORATION
Funding Number(s)
CONTRACT_GRANT: NGR-39-007-043
Distribution Limits
Public
Copyright
Other