Rock Type: Fossiliferous limestone
Location: Georgian Bay Formation, Manitoulin Island
Description: The fossils are fragments of Echinoderms, Bryozoan, and Ostrocods ranging from 0.25 to 4.5 mm in size. Several of the fossils were recrystallized to calcite and are subsequently replaced, in part, by fine-grained equigranular dolomite-ankerite solid solution. The fine-grained dolomite that makes up much of the matrix interstitial to the fossils is intercalated with very fine, dark brown clays.