On some sources of errors in phase‐equilibria investigations at ultra‐high pressure; phase diagram of silica

1 January 1967

journal article
research article
Published by Wiley in Geological Journal

Vol. 5 (2) , 321-328
https://doi.org/10.1002/gj.3350050207

Abstract

Large pressure gradients and unrecognizable variations of pressure occur when solid substances are compressee by cold anvils (pistons) and heated by internal heaters. To improve the reliability of the results the miniaturization of samples and preliminary firing of pyrophyllite (which transmits pressure) are suggested. The equilibrium coesite—stishovite may be empirically expressed as:P_kb = 85 + 0·364 T (°C)Stishovite must be playing an important role in the mantle at depths greater than 500 km. Quartz and stishovite do not coexist in nature whatever PT‐conditions are.

Keywords

This publication has 2 references indexed in Scilit:

PT‐diagram of the system SiO₂‐H₂O
Geological Journal, 1966
High‐low quartz inversion up to 10,000 bars
EOS, Transactions American Geophysical Union, 1950