FREE-ENERGY MINIMIZATION BY SIMULATED ANNEALING WITH APPLICATIONS TO LITHOSPHERIC SLABS AND MANTLE PLUMES

Authors
Citation
Cr. Bina, FREE-ENERGY MINIMIZATION BY SIMULATED ANNEALING WITH APPLICATIONS TO LITHOSPHERIC SLABS AND MANTLE PLUMES, Pure and Applied Geophysics, 151(2-4), 1998, pp. 605-618
Citations number
66
Categorie Soggetti
Geochemitry & Geophysics
Journal title
ISSN journal
00334553
Volume
151
Issue
2-4
Year of publication
1998
Pages
605 - 618
Database
ISI
SICI code
0033-4553(1998)151:2-4<605:FMBSAW>2.0.ZU;2-W
Abstract
An optimization algorithm based upon the method of simulated annealing is of utility in calculating equilibrium phase assemblages as functio ns of pressure, temperature, and chemical composition. Operating by an alogy to the statistical mechanics of the chemical system, it is appli cable both to problems of strict chemical equilibrium and to problems involving metastability. The method reproduces known phase diagrams an d illustrates the expected thermal deflection of phase transitions in thermal models of subducting lithospheric slabs and buoyant mantle plu mes. It reveals temperature-induced changes in phase transition sharpn ess and the stability of Fe-rich gamma phase within an alpha + gamma f ield in cold slab thermal models, and it suggests that transitions suc h as the possible breakdown of silicate perovskite to mixed oxides can amplify velocity anomalies.