Grain-scale pressure variations and chemical equilibrium in high-grade metamorphic rocks
L Tajcmanova, Y Podladchikov, R Powell, E Moulas, JC Vrijmoed, JAD Connolly
JOURNAL OF METAMORPHIC GEOLOGY | WILEY | Published : 2014
In the classical view of metamorphic microstructures, fast viscous relaxation (and so constant pressure) is assumed, with diffusion being the limiting factor in equilibration. This contribution is focused on the only other possible scenario - fast diffusion and slow viscous relaxation - and brings an alternative interpretation of microstructures typical of high-grade metamorphic rocks. In contrast to the pressure vessel mechanical model applied to pressure variation associated with coesite inclusions in various host minerals, a multi-anvil mechanical model is proposed in which strong single crystals and weak grain boundaries can maintain pressure variation at geological time-scales in a poly..View full abstract
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Awarded by ARC
Financial support for this project came from the European Commission (the Marie Curie Intra-European Fellowship Program) to LT. RP acknowledges support from ARC DP0987731. E. M. acknowledges the Alexander S. Onassis Public Benefit Foundation for financial support. We thank T. Gerya, D. Schmid, M. Dabrowski and five anonymous reviewers for their constructive comments, which improved to clarify the overall aim and mechanical part of the manuscript. M. Brown is acknowledged for careful editorial handling and patience.