Complex sentence: The Toroweap Fault, west of Aubrey Valley in the south and at Prospect Valley to the northwest, created the Aubrey Cliffs, which form part of the southwest perimeter of the Coconino Plateau.
Split into simpler sentences: The Toroweap Fault, west of Aubrey Valley in the south, and of Prospect Valley in the northwest, formed the Aubrey Cliffs. The cliffs form part of the southwest perimeter of the Coconino Plateau.