Complex sentence: The area experienced the effects of the early stages of Alpine collision during the Late Cretaceous to Palaeogene with reverse reactivation of many of the extensional faults, creating the most visible of the structures in the Dorset area, such as the Purbeck Monocline.
Split into simpler sentences: The area experienced the effects of the early stages of Alpine collision during the Late Cretaceous with reverse reactivation of many of the extensional faults. A further phase of inversion reactivated these faults again during the Paleogene, creating the most visible of the structures in the Dorset area, such as the Purbeck Monocline.