Fig. 9

Field and microscopic aspect of the Clapier Orthogneiss. a A layered facies of the Clapier orthogneiss, with centimetre to decimetre scale layering related to differences in modal proportions of quartz, alkali feldspar and mica (44° 59′ 25.79′′ N–7° 06′ 20.23′′ E). b A homogenous facies with K-feldspar clasts and a well-developed foliation marked by muscovite (44° 59′ 2151′′ N–7° 06′ 15.38′′ E). Microphotographs show a twinned alkali feldspar (c), interpreted as a relict magmatic mineral, and deformed flakes of white mica (d), in a matrix of recrystallized quartz and albite