Fig. 5

Structural relationships of the main lithologies in the studied area. UTM coordinates for each photograph are given. a Note that the enclave in the Mont Morion biotite-bearing granite is elongated parallel to the magmatic fabric, but perpendicular to the composite dyke (375523/5082870). The dyke shows a tabular shape and an internal fabric parallel to its margin. b, c Detail of the contact between the migmatitic biotite- gneiss and the Mont Morion biotite-bearing granite: a centimetre-thick selvedge of biotite develops at the interface between the granite and the gneiss (375408/5082762). The contact is gently folded. d An aplitic dyke cuts the migmatitic biotite-gneiss (375490/5082651). e Metre-scale xenoliths of migmatitic biotite-gneiss in the Mont Morion biotite-bearing granite in the proximity of the contact between the Mont Morion biotite-bearing granite itself and the main gneissic body at the foot of the Pic de la Vierge (375196/5082809). Note the elongation of the xenoliths parallel to the magmatic foliation in the Mont Morion granite. f Photomicrographs of migmatitic biotite-gneiss. Biotite films (melanosomes) and quartz-feldspar layers (leucosomes) define the migmatitic layering (plane-polarized light)