Chalk Biozone 10 - Cannosphaeropsis utinensis
Age: Mid Santonian.
Macrofaunal correlation: The lower U. socialis Zone.
Definition: The interval between the LAD of Endoscrinium campanula to the FAD of Cannosphaeropsis utinensis.
Comments: The FAD of Cannosphaeropsis utinensis occurs within the U. socialis Zone and is a reliable biomarker for the mid Santonian (Foucher, 1979; Foucher & Monteil, 1998). Alternative indices for the top of this biozone are the FAD of Canningia senonica and the LAD of Heterosphaeridium difficile (see Foucher, 1979; Haq et al., 1987; Costa & Davey, 1992; Wilkinson et al., 1993).
Lithostratigraphical correlation: The lowermost Newhaven Chalk Formation (Southern Province), the Flamborough Chalk Formation (Northern Province) and the Mackerel Formation (North Sea).