Sevier orogeny east. In contrast, the Laramide orogeny produced “basement-cored” uplifts that often took advantage of pre-existing faults that formed during rifting in the Late Precambrian during the breakup of the supercontinent Rodinia or during the Ancestral Rocky Mountains orogeny. The Sevier orogenic belt consisted of a series of thin plates along gently dipping west thrust sheets and moving from west to east. These thin skinned thrusts moved late Precambrian to Mesozoic age rock of the Cordilleran passive margin east. The Sevier meets the Laramide orogenic belt on its eastern side. The Sevier and Laramide combination is similar to the modern day
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