Thermobarometry using multi-equilibrium calculations; a new technique, with petrological applications
Thermobarometry using multi-equilibrium calculations; a new technique, with petrological applications (in Quantitative methods in petrology; an issue in honor of Hugh J. Greenwood, T. M. Gordon (editor) and R. F. Martin (editor))
The Canadian Mineralogist (December 1991) 29, Part 4: 833-855
An internally consistent method for performing thermobarometric calculations is described (TWEEQU: Thermobarometry With Estimation of EQUilibration state),in which all possible equilibria implied by a given mineral assemblage are computed, using an internally consistent set of thermodynamic data for end-members and mixing properties. Several examples show that convergence of all equilibria in a single P-T region correlates well with textural and chemical indications of equilibrium, suggesting that this technique makes it possible to reasonably assess the state of equilibration of samples for systems in which the thermodynamic properties are well described. One implication is that portions of P-T paths may be reconstructed from rocks that display disequilibrium textures but that pass this test for local equiibrium.
