Dunhill Bluff Limestone Member of Fossil Hill Limestone.
2.6 m thick coral/stromatoporoid biohermal mass.
85 % of biovolume formed by Tetradium cribriforme (up to 40x30 cm diameter) at base. Takeover by stromatoporoids up section reaching 50 % of biovolume at top.
Other corals: Nycropora, Bajgolia, encrusting Dualites, cerioid Eofletcheria, solitary Hillophyllum.
Stromatoporoids: Cystistroma, Labechia, Stratodictyon, Rosenella.
Skeletal wackestone matrix, although sediments above and below are grainstones.
Additional mound occur in Taplow limestone member, Transmission limestone member.