Area: 62.6 hectares.
Site of Special Scientific Interest (SSSI) notified under the National Parks and Access to the Countryside Act 1949.
Description and Reasons for Notification:
Southacre Clay Pits is a key locality for interpreting the stratigraphy, paleogeography and palaeoenvironmental conditions of the late Palaeogene within the Bovey Basin and more widely.
Stratigraphically, Southacre Clay Pits exposes lignite and clay sediments belonging to the Middle and Upper Bovey Formation of Oligocene age. It is the type locality for the Southacre Clay-and-Lignite Member (including the Parks Seam) of the Middle Bovey Formation. This is overlain by the Stover Member which belongs to the Upper Bover Formation.
The lignite beds (some reaching 3 metres in thickness) of the Southacre Clay-and-Lignite Member have yielded an abundant and diverse fossil flora – 33 named species belonging to 31 families of trees and other vegetation have been identified. Sedimentation in the Bovey Basin is believed to have taken place on a river flood plan and, to a lesser extent, in freshwater lakes. These environments are reflected by a largely derived flora dominated by the conifer Sequoia couttsiae with the fern Osmunda lignitum and the swamp-palm Calmus daemonorops. Also found are a number of true aquatic plants, marsh plants and various climbers, trees and shrubs.
Pollen and spore assemblages from sections at the site closely resemble those found in sediments of similar age in the Bristol Channel, the Irish Sea and Ulster making this site important for understanding the late Palaeogene in the Bovey Basin and for localities of similar age throughout Britain.