Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 1, 2000 | public
Book Section - Chapter Open

Shock induced vaporization of anhydrite CaSO4 and calcite CaCO3

Abstract

Discovery of abundant anhydrite (CaSO4) and gypsum (CaSO4.2H2O) in the otherwise carbonate sediments comprising the upper portion of the rocks contained within the Chicxulub impact crater has prompted research on the shock-induced vaporization of these minerals. We use a vaporization criterion determined by shock-induced entropy. We reanalyze the shock wave experiments of Yang [1]. He shocked 30% porous anhydrite and 46% porous calcite. Post-shock adiabatic expansion of the sample across a 5 mm-thick gap and then impact upon an aluminum witness plate backed by LiF window that is monitored with a VISAR. Reanalysis uses Herrman's P-alpha model [2] for porous materials, and a realistic interpolation gas equation-of-state for vaporization products. Derived values of the entropies for incipient and complete vaporization for anhydrite are 1.65±0.12 and 3.17±0.12 kJ(kg.K)–1, and for calcite these are 0.99±0.11 and 1.93±0.11 kJ(kg.K)–1. Corresponding pressures for incipient and complete vaporization along the Hugoniot of non-porous anhydrite are 32.5±2.5 and 122±13 GPa and for non-porous calcite are 17.8±2.9 and 54.1±5.3 GPa, respectively. These pressures are a factor of 2–3 lower than reported earlier by Yang.

Additional Information

©2000 American Institute of Physics. Research supported by NASA. Contribution number 8672 of Division of Geological and Planetary Sciences, (Caltech).

Files

GUPaipcp00b.pdf
Files (1.2 MB)
Name Size Download all
md5:990431a6294c3b03b47d34f988ecdb01
1.2 MB Preview Download

Additional details

Created:
August 21, 2023
Modified:
October 16, 2023