Quartz fabric transition in a cooling syntectonic granite (Hermitage Massif, France)

摘要: Abstract The Hermitage Granite, situated in the northwest Massif Central (France) is a syntectonic Hercynian leucogranite emplaced along an active transcurrent shear zone. During emplacement and cooling, progressive deformation marked by development of primary homogeneous foliation gradually affected ductile bands (C-S mylonites). Increase strain heterogeneity during cooling corresponds to change dominant mechanism quartz phase from grain growth migration recrystallization intracrystalline 〈 〉 slip rotation recrystallization. Migration characterized preferred orientations c axes close principal extension direction. We discuss relevant mechanisms rheological implications for plutons. In particular, we argue that transitions between heterogeneous accumulation cannot generally be correlated with transition magmatic solid-state flow.