Griffith & Brydone (1911); Brydone (1912) - Actinocamax quadratus Zone

From Earthwise
Jump to navigation Jump to search

Biostratigraphical correlation: Equates with an interval from within the topmost O. pilula Zone to either at or just below the top of the G. quadrata Zone of current usage. Griffith & Brydone (1911) defined the quadrata / mucronata Zone boundary at the Farlington Marls, consistent with the current interpretation, but Brydone (1912) subsequently lowered the top of the zone to at or slightly below Bedhampton Marl 1 (Wood, WH/95/31R).

Lithostratigraphical correlation: Equates with the Culver Chalk Formation (and locally topmost Newhaven Chalk Formation) and basal Portsdown Chalk Formation of southern England.

Age: Campanian