The type section 20 miles (32 km) south of Adelaide has been re-examined. Comprising about 107 feet (32½ m) of bryozoal calcarenitic impure limestones, sands, silts, and clays, it is informally subdivided into three apparently conformable successions of beds, the middle interval characterised by horizons with spicular cherty nodules. Equivalents of these three intervals are present in the Willunga Bore W.B.1, and in bores in the Adelaide Plains Sub-basin. The top of the Eocene Aldingan Stage is represented by the top of a hard grey marker bed at the base of the siliceous interval about 45 feet (14 m) above the base of the formation. Planktonic and benthonic foraminifera indicate that the age of the section ranges from Upper Eocene to Oligocene. Four informal planktonic zones are recognised, using successive extinctions of Turborotalia aculeate (Jenkins), Globigerina linaporta (Finlay), Chiloguembelina cubensis (Palmer) and Guembelitria stavensis Bandy. These zones span Aldingan to lower Janjukian Stages, and can be related to a planktonic zonal scheme recently proposed for New Zealand.