Late Middle Pleistocene deposits at Norton Farm on the West Sussex coastalplain, southern England

The coastal plain of West Sussex, southern England, is internationally impo rtant because of the sequence of discrete high-sea-level events preserved a t Various elevations across it. New evidence is presented from a site at No rton Farm, near Chichester, on the Lower Coastal Plain, where Pleistocene m arine sands, fining upwards into silts, occur between 5.3 m and 9.1 m OD. T he sequence reflects a regressive tendency at the transition from an interg lacial to a cold stage. The marine sands have yielded foraminifera, ostraco ds and molluscs that indicate a declining marine influence through the sequ ence, culminating in a tidal mudflat, strongly weathered in places. Cool-cl imate foraminifera (including Elphidium clavatum, Cassidulina reniformis an d Elphidium albiumbilicatum) and ostracods have been recovered from the mar ine sands. Some species with an apparent preference for warmer water condit ions, however, are also present. Freshwater taxa washed into the terminal m arine sediments include some cold climate indicators, such as Pisidium stew arti and P. obtusale lapponicum. Additional evidence for cool climatic cond itions during the deposition of the upper part of the marine sequence is pr ovided by the lack of tree taxa in the pollen record and by features of the micromorphology. The marine sediments probably began accumulating during O IS 7, a conclusion based on their elevation, on amino acid ratios from shel ls, but especially on vertebrate evidence, particularly the presence of a s mall form of horse, together with a large, distinctive, form of northern vo le (Microtus oeconomus). The occurrence of cool climate indicators in these marine sediments may demonstrate a lag between the climatic deterioration and the expected glacio-eustatic fall in relative sea-level. This evidence appears to support the conclusions drawn from the study of coral terraces i n Barbados. Such a scenario would provide the conditions necessary for the emplacement of the large erratic boulders reported from the Lower Coastal P lain of West Sussex. Copyright (C) 2000 John Wiley & Sons, Ltd.