Purbeck, district (1991 pop. 42,600), Dorset, England. Purbeck is filled with the clays of the Hampshire Basin, and is therefore largely infertile. Some minor farming occurs on the chalk plateaus and ridges in the northern and southern extremities of the district. Purbeck is drained by the Trent and Frome rivers. Wareham and Swanage are the main towns of the area. Marble quarrying, oil-field work, and nuclear power plant operation comprise Purbeck's economic activities. The region was once thought to be infested with smugglers, who could easily hide in its forests and on its ridges. Poole Harbour attracts many boaters, while the district's varied strata appeals to geologists. Purbeck gets its name from the ancient Isle of Purbeck.