Cheddar Complex the Pleistocene period. Cheddar Caves contain both active and fossil systems. The active cave system is one of the most heavily studied karst systems in Britain with reference to the conduit and diffuse flow characteristics of its hydrology. Charterhouse Caves include four major swallet caves that provide an indisputable record of Pleistocene landform development in the Mendips and surrounding area. Sun Hole Cave provides a varied fauna radiocarbon-dated to the end of the Late Devensian Cold Stage. Several types of limestone including Clifton Down Limestone, Cheddar Limestone and Cheddar Oolite are visible in the Gorge and surrounding areas with pale
Wookey Hole Caves resurgences. In particular, the passages in the 20th chamber are interpreted as a former Vauclusian spring, the waters of which once surfaced in the Ebbor Gorge. It is uncertain whether that was the original rising or whether it formed when the main rising at Wookey was blocked. The current resurgence is located close to the base of the Dolomitic Conglomerate at the head of a short gorge formed by headward erosion with subsequent cavern collapse. The morphology of the passages is determined by the rock strata in which they are formed. The streamway in the outer part of the cave