A proposed latest Triassic to earliest Cretaceous microfossil biozonation for the English Channel and its adjacent areas

Abstract Three detailed biostratigraphic zonations, based on ostracods, foraminiferids and dinocysts, are proposed for the latest Triassic through to the earliest Cretaceous of the Portland-Wight Basin and its adjacent areas. A total of 112 zones-zonules (34 ostracod zones/subzones, 25 foraminiferid zones, 53 dinoflagellate zones, subzones and zonules) are recognized. All three zonation schemes are based on samples obtained from both outcrop (the Dorset coast) and boreholes, the latter from ditch cuttings, with some conventional and sidewall core samples, in association with published data, and have where possible been calibrated to the standard ammonite zones recognized throughout northwest Europe.