The stratigraphy of the 'Corallian' facies Middle Oxfordian (Upper Jurassic) deposits at Upware, Cambridgeshire, England

At Upware, Cambridgeshire, an inlier of 'Corallian' facies Middle Oxfordian limestone within the more typical mudrock-dominated West Walton Formation sequence of the East Midlands Shelf, forms a topographic feature of low rel ief for 6 km. Recent deep excavations in the district have revealed the bas e of these beds, not exposed since the last century. They and the underlyin g mudrock have yielded prolific bivalve faunas and common ammonite faunas, including both Boreal (Cardioceratidae) and Tethyan (Perisphinctinae) eleme nts. The stratigraphy of these Middle Oxfordian deposits is revised, and th e palaeoenvironment of the benthic macroinvertebrate faunas of the successi on is discussed. The Boreal bivalve Praebuchia lata (Trautschold), a new re cord of biostratigraphic significance, is described and figured.