Purbeck stone

Purbeck stone refers to building stone taken from a series of limestone beds found in the Upper Jurassic to Lower Cretaceous Purbeck Group, found on the Isle of Purbeck, Dorset in southern England. The best known variety of this stone is Purbeck Marble. The stone has been quarried since at least Roman times up to the present day.

Geology

The Purbeck Group is a sequence of sedimentary rocks that were deposited in a shallow freshwater to brackish lagoonal setting. It ranges in age from Tithonian to Berriasian. Limestone beds are developed at various levels throughout the sequence, each with a different character, which led to them being quarried for specific uses. Towards the top of the Lulworth Formation is the 'New Vein'. In the lower part of the Durlston Formation are the 'Downs vein, 'Freestone Vein' and the 'Laning Vein'. Towards the top of the Durlston are the 'Burr' (or Broken Shell Limestone) with up to three beds of the 'Purbeck Marble' above that.

Occurrence

The Purbeck Group outcrops or is found beneath superficial deposits from Worbarrow Tout in the west, to Peveril Point in the east. The sequence is affected by the Purbeck Monocline and dips moderately steeply to the north along its whole outcrop.