6533b82afe1ef96bd128c300

RESEARCH PRODUCT

Activity-composition relations for the calculation of partial melting equilibria in metabasic rocks

Richard WhiteJohann F.a. DienerTim HollandEleanor C. R. GreenRoger PowellRichard M. Palin

subject

010504 meteorology & atmospheric sciencesPartial meltingMineralogyThermodynamicsGeologyComposition (combinatorics)010502 geochemistry & geophysics01 natural sciencesSilicatechemistry.chemical_compoundchemistryGeochemistry and PetrologyTetrahedronGeologyMixing (physics)0105 earth and related environmental sciencesSolid solution

description

A set of thermodynamic models is presented that, for the first time, allows partial melting equilibria to be calculated for metabasic rocks. The models consist of new activity–composition relations combined with end-member thermodynamic properties from the Holland & Powell dataset, version 6. They allow for forward modelling in the system Na (Formula presented.) O–CaO–K (Formula presented.) O–FeO–MgO–Al (Formula presented.) O (Formula presented.) –SiO (Formula presented.) –H (Formula presented.) O–TiO (Formula presented.) –Fe (Formula presented.) O (Formula presented.). In particular, new activity–composition relations are presented for silicate melt of broadly trondhjemitic–tonalitic composition, and for augitic clinopyroxene with Si–Al mixing on the tetrahedral sites, while existing activity–composition relations for hornblende are extended to include K (Formula presented.) O and TiO (Formula presented.). Calibration of the activity–composition relations was carried out with the aim of reproducing major experimental phase-in/phase-out boundaries that define the amphibolite–granulite transition, across a range of bulk compositions, at ≤13 kbar.

yearjournalcountryeditionlanguage
2020-01-13Journal of Metamorphic Geology
10.1111/jmg.12211http://ora.ox.ac.uk/objects/uuid: