The haldon gravels of South Devon

Abstract

The Haldon Gravels comprise four components, three Eocene and one Pleistocene. The Tower Wood Gravel, of early Eocene age, contains weathered but unabraded flints in a clay matrix of well-ordered kaolinite with little illite, and was formed from in situ solution of the Chalk. The overlying Buller's Hill Gravel contains abraded flints and exotic pebbles in a matrix of kaolin clay and sand; it was formed largely by fluvial reworking of the Tower Wood Gravel on a wide flat plain during approximately Reading Beds to Bagshot Beds times. Bodies of ‘ball-clay’ kaolin now found within the Buller's Hill Gravel but differing from it in their clay mineralogy originated as a sheet of clay overlying the gravel, deposited on a river flood-plain or in a coastal lagoon and tentatively correlated with the Bracklesham and Barton Beds. Downwarping of the Bovey Basin prevented further, sedimentation in the area. During the Pleistocene the Haldon Gravels were affected by periglacial processes; the flints were frost-shattered, the gravels mixed by cryoturbation and solifluction to form Head Gravel, and the overlying sheet of clay broken up and incorporated as masses of clay in the Buller's Hill Gravel.