the collision initiated a sequence of events where the older rocks on laurentia and avalonia were subjected deformation, plutonism, metamorphism, and uplift that occurred over a large area of eastern laurentia (naylor). during the course of the orogeny, new faults formed, while older faults were reactivated. acadian deformation and metamorphism were asymmetric across the strike of the orogen. the acadian plutons intruded every belt, unlike the deformation/metamorphism, of avalonia which did not undergo much of the alteration shown in other localities (bradley). during the middle devonian, centers for volcanoes and uplift formed in the new england region and shed fine-grained clastic material into an inland seaway that covered a large part of southern and central appalachia.