JavaScript requeired.
Geochemical Journal
Geochemical Journal An open access journal for geochemistry
subscription
Published for geochemistry community from Geochemical Society of Japan.

Segregation in ternary solutions

Lawrence M. Barron
Geochemical Journal, Vol. 10, No. 3, P. 145-154, 1976

ABSTRACT

The spinodal surface and the stable binodal surface must touch tangentially at any extremum/saddle point and along any consolute line. Because of this, the most convenient way to study immiscibility in a ternary is to calculate the spinodal surface. Other authors have accomplished this in a binary regular and subregular solution and in a ternary regular solution but the derived equations are not applicable to a ternary subregular solution or to a Kohler solution. The equation for the spinodal in a ternary Kohler solution is herein derived so that now it is possible to study immiscibility using the spinodal in any ternary Kohler solution, including a subregular ternary solution. MEIJIRING used the spinodal equation to derive relations which characterise the form of segregation in a ternary regular solution. When the “effective” regular solution parameter is substituted into these relations, they can be used as a rough approximation to characterise segregation in a subregular ternary solution; the number of peaks and saddles in the ternary solvus can be predicted but the temperature/composition of them cannot. This rough scheme is used with a graph which shows that the composition of the critical point on a subregular binary solvus is only a function of the ratio of the two subregular parameters. The temperature dependence of subregular solution parameters is capable of exerting a strong control on the unique features of a ternary spinodal, so that a more exact study of immiscibility must involve the calculation of the spinodal surface using temperature dependent solution parameters. A model spinodal for the ternary feldspar system at l kb is calculated using temperature dependent subregular solution parameters.

All Issues

Current Issue:
Stats:
Impact Factor: 0.8 (2022)
Submission to final decision: 9.6 weeks (2022)
Geochemical Society of Japan

page top