Accession Number:

ADA301302

Title:

Equation of State of Clay, Shale and Slate.

Descriptive Note:

Technical rept. 30 Sep 92-30 Apr 95,

Corporate Author:

CALIFORNIA INST OF TECH PASADENA SEISMOLOGICAL LAB

Report Date:

1995-11-01

Pagination or Media Count:

60.0

Abstract:

New shock compression and release adiabat data to approx. 150 GPa are reported for kaolinite clay and rocks derived from clay- and mica-rich materials. The kaolinite data yield an STP isentropic bulk modulus Kso of 49.4 GPa. This is very similar to K for muscovite mica 52 GPa, although the density is lower 2.594 Mgrn3 vs. 2.835 Mgrn3 for muscovite. Unlike muscovite, kaolinite apparently transforms to a new unidentified phase under shock compression. Carbonate-poor shale approx. 8 CaCO3 by weight is less compressible Ks0 61.1 GPa than a carbonate-rich -33 CaCO3 by weight shale Kso 30.9 GPa. This appears to be the result of the claymica ratio and the presence of zeolitic water in the carbonate-rich shale rather than carbonate content. The compressibility of slate Kso 50.5 GPa is very similar to that of carbonate-poor shale at low pressures. All of these rocks transform to high-pressure phase assemblages, with marked increases in density r 3.359, 3.659, 3.740, and 4.110 Mgrn3 for kaolinite, carbonate-rich and carbonate-poor shales, and slate, respectively, at P 0, on shock compression. The behavior of this high pressure phase material is strongly influenced by the abundance of H2O in the rock. Release adiabat data show conversion of high- to low-density material in kaolinite and shales upon release, but not in slate. AN

Subject Categories:

  • Geology, Geochemistry and Mineralogy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE