sentences:  The upper division (ex-Keuper) follows the lower (ex-Bunter) unconformably.The upper is very thick and in Cheshire reaches a thickness of about 1250 m, locally conglomeritic, but consists mainly of fine water lain sandstones.Interest in the area took off with vigour in the mid-19th century with the first real efforts made to quantify the strata of the country using the new mapping methods that geologists like William Smith had pioneered.