Essex

Abstract

Several sites in the extreme south-west of Essex have been described already, in Chapter 4, as they fall within the Lower Thames valley. Pleistocene fluvial deposits are widespread in the remainder of the county and their study has been of great importance in reconstructing the evolution of the Thames drainage system. The succession in Essex comprises not only the deposits of the River Thames (both pre-and post-diversion), but also of its major right-bank tributary, the Medway. A number of more recently formed left-bank Thames tributaries, which now drain the northern part of the county (Fig. 5.1), are also represented. Pleistocene sites in this area included in the Geological Conservation Review invariably reflect aspects of drainage development. At a few sites, interbedded glacial sediments are included, from which can be demonstrated the advance of the Anglian ice sheets into the area. Buried soil layers form an important part of the interest at some sites. There are also a number of important Palaeolithic localities, the most notable of which is at Clacton, the type locality for the Clactonian Industry and a site of great importance to Pleistocene geology.