 Above this in south east Tasmania are more marine units that include Nassau Formation Berriedale Limestone, up to 60 m thick, siltstone and sandstone rich in fossils and dropstones (Malbina Formation, and
Deep Bay Formation), and the upper part is dark grey siltstone rich in dropstones.The very top layers are coloured black, probably from an estuary (Risdon Sandstone and the Abels Bay Formation).Felsic volcanic ash is found near the top of the sequence of sediments.