Published online by Cambridge University Press: 01 May 2009
The occurrence of stout and stumpy crystals of biotite elongated parallel to the schistosity and showing askew cleavage is found to be due to rotation. The relation between rotation of biotite and deformation is described. Rotated biotite contains a higher amount of FeO, TiO2 and Al2O3 in comparison to the unrotated fresh and recrystallized biotite.