The stratigraphy and palaeontology of the Upper Weald Clay (Barremian) at Smokejacks Brickworks, Ockley, Surrey, England

Abstract

The stratigraphy of the Weald Clay of Surrey is summarized. The Hauterivian/Barremian boundary is shown to correspond closely to the Lower Weald Clay/Upper Weald Clay boundary, which lies at the base of BGS (British Geological Survey) Bed 3a and is close to the Ewhurst/Capel ostracod faunicycle boundary. Detailed sections of the sediments exposed in the pit at Smokejacks Brickworks are published for the first time. BGS Bed 5c is present at the top of the pit, which indicates that the sediments belong to the Upper Weald Clay and suggests an early Barremian age for this site. The pit has yielded a diverse non-marine fossil fauna and flora consisting of the remains of insects, crustacea, bivalves, dinosaurs (including Baryonyx walkeri), pterosaurs, crocodiles, sharks, bony fish, club mosses, horsetails, ferns, conifers and a primitive aquatic or marsh-dwelling herbaceous plant. The extinct lacewing family Brongniartiellidae is recorded from the Barremian for the first time. The sediments exposed in Smokejacks pit and their fossil content indicate a shallowing upwards sequence, documenting a change from a lacustrine/lagoonal to a fluvial/mudplain environment.