Towards the end of the Precambrian period, the volcanoes ceased their eruptions, and the rivers had dried up. Instead the forces that created the volcanoes caused the new rocks to lift and fold, creating mountains and valleys in the area. Much of the rock was melted during this period, underneath the Earth's crust, causing the mountains to continually change towards the latter part of the Precambrian. The Church Stretton Fault zone probably formed during this period. It is still active today. The hill Caer Caradoc adjacent to the Long Mynd and from the same time is volcanic in origin, and is thought to be a remnant of the great mountain chain.