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Diffusion Creep of Diopside
Author(s) -
Ghosh S.,
Koizumi S.,
Hiraga T.
Publication year - 2021
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1029/2020jb019855
Subject(s) - creep , diopside , forsterite , diffusion creep , anorthite , materials science , grain size , mineralogy , diffusion , strain rate , thermodynamics , activation energy , composite material , geology , grain boundary , chemistry , microstructure , physics
We have conducted uniaxial compression experiments on fine‐grained diopside with either 4 or 10 vol% forsterite and 10 vol% anorthite. We changed the average grain size in the diopside with forsterite aggregate from 0.43 to 4.07 μm to reveal the grain size sensitivity of the creep rate. Mechanical data were obtained at a stepped load for a temperature range of 1050°C–1170°C. The observed strain rates are best explained by stress and grain size exponent values of 1 and 2, respectively, and activation energy of ∼720 kJ/mol, which indicates lattice diffusion creep. Anorthite bearing aggregate is ∼3 times weaker than forsterite‐bearing aggregate, probably due to the presence of aluminum. We have compared previously reported diffusion creep rates of diopside in nondimensional stress and strain‐rate space, constructed based on our diffusion creep law. It demonstrates that all the earlier mechanical data are well summarized by our diffusion creep flow law.