The microstructure generally indicates a predominance of simple shear deformation and a retrogression of the primary, high-temperature igneous mineral assemblage.
This growth of pargasite and oligoclase indicates further retrogression to upper amphibolite facies conditions following the high-pressure granulite facies overprint.
This textural evidence indicates that garnet was in equilibrium with amphibole, plagioclase and quartz during this stage of retrogression.
Moreover, retrogression (recruitment of individuals to a precedent stage) increases the standard deviation of age-based parameters and is another clue of plasticity.
Yet to resist by means of a retrogression in performance style is merely to adhere to a stereotype.
The second retrogressive stage is marked by the retrogression of the medium- to low-pressure granulite facies mineral assemblages into the amphibolite facies.
In metre-scale pods, the core consists of the least retrogressed eclogite with increasing retrogression towards the margin.
However, it is unlikely that peak temperatures are preserved in the re-equilibrated phases because of subsequent pervasive garnet-forming reactions and late retrogression.
