The Variscan orogeny caused the intrusion of the hot granite. The subsequent contact with the sandstones created the metamorphic rocks seen today. This also put intense pressure on the sediments causing them to be folded and faulted. What we see is a small part of a huge mountain system caused by a continental collision between Euramerica (Laurussia) and Gondwana. This formed the supercontinent of Pangaea.