 The site comprises a network of tunnels and surface exposures on the eastern fringe of Compton Wood.The site exposes bedded hematitic iron ore (red ochre) in Triassic Dolomitic Conglomerates which was deposited underwater as a layered mass of iron oxide pellets of various types, probably in an ephemeral lake or pond fed by hot springs when the Mendip area was occupied by a desert environment some 220 million years ago during late Triassic times.Red ochre is an iron oxide mineral, which was used in paint-making.