Orogeny progressively involved in folding and thrusting. Sediments deposited in the foreland basin are mainly derived from the erosion of the actively uplifting rocks of the mountain range, although some sediments derive from the foreland. The fill of many such basins shows a change in time from deepwater marine ("flysch"-style) through shallow water to continental ("molasse"-style) sediments. Although orogeny involves plate tectonics, the tectonic forces result in a variety of associated phenomena, including crustal deformation, crustal thickening, crustal thinning and crustal melting as well as magmatism, metamorphism and mineralization. What exactly happens in a specific orogen depends upon the strength and
Cadomian Orogeny de Tréguier" and "Ignimbrites de Lézardrieux". The southern edge of the Gulf of Saint-Malo between Tregor and Cancale shows the deformational structures of the Cadomian Orogeny. These are East-west to North East trending upright folding. Schistosity is developed parallel to the axial plane of the folds. Prehnite-pumpellyite facies to mid-amphibolite facies have been produced by metamorphism. Movement was concentrated in shear belts such as at St Cast. The movement on the belts was sinistral and horizontal. During the orogeny the migmatite belts of north east Brittany were formed. Baie de St Brieuc and St Malo migmatites were deformed with the