NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Dynamic compression and volatile release of carbonatesParticle velocity profiles upon shock compression and isentropic releases were measured for polycrystalline calcite. The Solenhofen limestone release paths lie close to the Hugoniot. Calcite 3 to 2 transition, upon release was observed, but rarefaction shocks were not detected. The equation of state is used to predict the fraction of material devolatilized upon isentropic release as a function of shock pressure. The effect of ambient partial pressure of CO2 on the calculations is demonstrated and considered in models of atmospheric evolution by impact induced mineral devolatilization. The radiative characteristics of shocked calcite indicate that localization of thermal energy occurs under shock compression. Shock entropy calculations result in a minimum estimate of 90 percent devolatilization upon complete release from 10 GPa. Isentropic release paths from calculated continuum Hugoniot temperatures cross into the CaO (solid) + CO2 (vapor) field at improbably low pressures. It is found that release paths from measured shock temperatures cross into the melt plus vapor field at pressures greater than .5 GPa, which suggests that devolatilization is initiated at the shear banding sites.
Document ID
19860051353
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Tyburczy, J. A.
(California Inst. of Tech. Pasadena, CA, United States)
Ahrens, T. J.
(California Institute of Technology Pasadena, United States)
Date Acquired
August 12, 2013
Publication Date
April 10, 1986
Publication Information
Publication: Journal of Geophysical Research
Volume: 91
ISSN: 0148-0227
Subject Category
Lunar And Planetary Exploration
Accession Number
86A36091
Funding Number(s)
CONTRACT_GRANT: NGL-05-002-105
Distribution Limits
Public
Copyright
Other

Available Downloads

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