Palaeoenvironmental significance of storm coquinas in a Lower Cretaceous coastal lagoonal succession (Vectis Formation, Isle of Wight, southern England)

Thin bioclastic limestone beds ('coquinas') in the Vectis Formation (Wealde n Group, Lower Cretaceous) of the Isle of Wight, southern England, exhibit a range of biofabrics and internal stratigraphies. These features are attri buted to both simple and complex storm deposition of allochthonous biogenic and siliciclastic materials in coastal lagoons and on adjacent mudflats. T hese modes of deposition facilitated preservation of dinosaur trackways, de siccation cracks, shallow-tier trace fossils and in situ bivalve colonies t hrough rapid burial. The coquinas thus preserve a record of surficial muds, commonly lost through reworking. The principal components of the coquinas comprise dispersed elements from within the argillaceous 'background' facie s. Some of these beds are laterally traceable for up to 27 km, providing th e foundations for a high-resolution event-stratigraphic framework.