Viscous relaxation of grain-scale pressure variations
M Dabrowski, R Powell, Y Podladchikov
JOURNAL OF METAMORPHIC GEOLOGY | WILEY | Published : 2015
In the presence of grain-scale pressure variations, there will be a natural tendency for deformation to flatten pressure gradients to establish pressure equilibrium. We explore the time-scale of the survival of pressure variations in the presence of power-law creep. Such viscous relaxation turns out to be strongly dependent on the exponent in the power-law creep constitutive relation. For larger exponents, there is the possibility of maintaining pressure variations for the order of a million years, orders of magnitude longer than the viscoelastic relaxation time that is commonly used as a proxy for the pressure relaxation time. Petrologically, this means that while pressure variations may on..View full abstract
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Awarded by Polish Geological Institute
Awarded by ARC
We thank N. Mancktelow and B. Kaus for their useful comments. This work was conducted within the Polish Geological Institute research project no. 61.9015.1301.00.1. MD acknowledges discussions with S. Medvedev and D. Schmid. RP acknowledges support from ARC DP0987731, and the hospitality of ETH, Zurich in 2014, courtesy of L. Tajcmanova.