NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Occurence and implications of silicon nitride in enstatic chondritesSilicon nitride Si3N4, has previously been observed to be a common constituent of acid residues of Qingzhen (EH3) and Indarch (EH4). Ion probe analysis of the Si, N and C isotopic compositions of individual Si3N4 grains from Qingzhen and Indarch acid residues suggest most, if not all, grains are Solar System in origin. A few grains have isotopically anomalous C but this is probably due to small presolar SiC grains adhering to them. In situ observations of the Si3N4 in Qingzhen show that it is only present within, and probably exsolved from, host phases which contain elemental Si in solid solution. Thermodynamic calculations suggest that the Si3N4 probably formed during metamorphism and not in the nebula. Thermodynamic calculations also show that sinoite (Si2N2O) and not Si3N4 should be the stable phase during metamorphism. It appears that kinetic factors must have inhibited the formation if sinoite in Qimgzhen and Indarch.
Document ID
19950051524
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Alexander, C. M. O'D.
(Washington Univ. Saint Louis, MO, United States)
Swan, P.
(Washington Univ. Saint Louis, MO, United States)
Prombo, C. A.
(Washington Univ. Saint Louis, MO, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1994
Publication Information
Publication: Meteoritics
Volume: 29
Issue: 1
ISSN: 0026-1114
Subject Category
Lunar And Planetary Exploration
Accession Number
95A83123
Funding Number(s)
CONTRACT_GRANT: NAG9-55
Distribution Limits
Public
Copyright
Other

Available Downloads

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