Comments on “Gale, A S., Norman Berry Peake, 1921-2010, a chalk revolutionary” [Proc. Geol. Assoc. 128 (2017), 829-839], and “Gale, A S & Lovell, B., The Cretaceous-Paleogene unconformity in England: Uplift and erosion related to the Iceland mantle plume” [Proc. Geol. Assoc. (2017) doi.org/10.1016/j.pgeola.2017.04.002]

Abstract

Certain misunderstandings expressed in two recent papers about the status of the ongoing revision of the geological maps of the Chalk in a large area of southern England, and about the methodology being used in that process, are here corrected. The contrast between a 'lithostratigraphical' and a 'biostratigraphical' approach to Chalk mapping is illustrated with an example area in the North Downs of eastern Surrey, western Kent and the adjacent part of Greater London. It is likely that significant faulting is present in the Chalk of this area, including a normal fault with a throw of about 30 m that passes under Croydon. The area provides the best available opportunity to observe in the field, and to map in exposed Chalk, structures that are likely to be similar to those that occur down-dip under London, concealed beneath Palaeogene cover.