Collignoniceras woollgari Zone
Base: The base of the zone is defined by the first appearance of the index species (Gale, 1996).
Correlation: The zone is presumably equivalent to the C. woollgari Zone of Wright & Kennedy (1981), and it equates with the upper Mytiloides spp. Zone and most of the T. lata Zone of the standard macrofossil zonal scheme.
Occurrence: Well-horizoned material occurs in the BGS Fetcham Mill Borehole [TQ 1581 5650], where the index occurs c, 22.8 m above the Melbourn Rock, and at Fognam, Berkshire, where it occurs c. 5 m below the Chalk Rock (Wright & Kennedy, 1981).