NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Calcic micas in the Allende meteorite - Evidence for hydration reactions in the early solar nebulaTwo calcic micas, clintonite and margarite, have been identified in alteration products in a calcium- and aluminum-rich inclusion (CAI) in the Allende meteorite. Clintonite replaces grossular in alteration veins, and margarite occurs as lamellae in anorthite. Their occurrence suggests that, in addition to undergoing high-temperature alteration by a volatile and iron-rich vapor that produced the grossular and anorthite, some CAIs underwent alteration at moderate temperatures (400 K or less). Petrographic evidence suggests that the calcic micas formed before accretion but after the formation of the layered rim sequences that surround the CAI. These calcic micas provide strong evidence that, contrary to theoretical calculations, some hydration reactions occurred in the early solar nebula.
Document ID
19910053626
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Keller, Lindsay P.
(NASA Johnson Space Center Houston, TX; Arizona State University, Tempe, United States)
Buseck, Peter R.
(Arizona State University Tempe, United States)
Date Acquired
August 15, 2013
Publication Date
May 17, 1991
Publication Information
Publication: Science
Volume: 252
ISSN: 0036-8075
Subject Category
Lunar And Planetary Exploration
Accession Number
91A38249
Funding Number(s)
CONTRACT_GRANT: NSF EAR-84-08163
CONTRACT_GRANT: NAG9-59
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available