Boreholes B2/73, B3/73 intersected (i) thin Quarternary units over ?Plio-Pleistocene Carisbrooke Sand, uncomformably overlying (without intervening Port Willunga Beds) (ii) an Eocene succession (correlated with the lower part of Reynolds' standard coastal section) comprising Blanche Point Banded Marl, Blanche Point Transitional Marl (with the important Hantkenina zone) and Tortachilla Limestone (Late Eocene), South Maslin Sand (?Late Eocene) and North Maslin Sand (Middle Eocene). The latter formation was incompletely penetrated to a maximum thickness of 24.5m in B2/73. An intercalation within it of black carbonaceous ("lignitic") clay at the bottom of B3/73 is palynologically slightly younger than, but comparable with, the notable black clay lens in type North Maslin Sand at the A.B.M-Readymix quarry, Maslin Beach.