The basal sands of the Red Crag Formation at Walton-on-the-Naze, Essex, contain a pollen assemblage dominated by Pinus and with pollen of Taxodiaceae and thermophilous trees. This is comparable with assemblages from the Dutch Reuverian ‘C’ (Late Pliocene). It is not closely comparable with spectra from other sections previously correlated with the Red Crag Formation at Walton, which arguably have Praetiglian affinities. Dinoflagellate cysts typical of warm-temperate water are also present, and compare well with assemblages from the Red Crag Formation in the southern North Sea. The ‘Pre-Ludhamian’ and ‘Waltonian’ are therefore separate stages assignable to the Pleistocene and Pliocene, respectively.
The base of the Walton Crag, the lowest division of the Red Crag Formation, at Walton-on-the-Naze, was long considered to be the local base for the Pleistocene in the British Isles, largely because of the presence of supposedly characteristic Pleistocene mammal fossils such as Mammuthus meridionalis, Equus sp. and Hipparion sp. (Boswell 1952; Mitchell et al. 1973; Funnell & West 1977; Harland et al. 1982). Other opinion (Zagwijn 1974; Funnell inCurry et al. 1978; Cameron et al. 1984) would attribute the Red Crag Formation to the Late Pliocene on the grounds of mollusc and foraminifer correlation with Belgian and Dutch Pliocene sequences.
The foraminifers from the Red Crag Formation at Walton-on-the-Naze are closely comparable with those from the Crag in the lower part of the Stradbroke Borehole (Beck et al. 1972; Funnell & West 1977). Pollen assemblages from the same unit in the Stradbroke Borehole were dominated by