Mid-Late Quaternary Fluvial Archives near the Margin of the MIS 12 Glaciation in Southern East Anglia, UK: Amalgamation of Multi-Disciplinary and Citizen-Science Data Sources

Abstract

This paper presents an updated geological reconstruction of the Quaternary evolution of the River Thames at its downstream extremities, close to the North Sea coast, based on new data from multi-disciplinary and citizen-science sources. In this area, the interaction of the Thames with the MIS 12 (Anglian) glaciation is an important part of the Quaternary archive. The Anglian ice sheet, which reached parts of north and east London, was responsible for diverting the Thames southwards into its present course, although the footprint of the maximum ice sheet(s) does not reach the North Sea coast south of Hollesley, Suffolk. Further south, the coastal zone hosts pre-Anglian and early Anglian river-terrace deposits of the pre-diversion Thames system, superimposed upon which are products of later post-Anglian rivers, of both Middle and Late Pleistocene age. On the peninsula between the Stour and Blackwater–Colne estuaries, the lowest and most recent terrace of the pre-diversion Thames includes evidence directly pertaining to the glacial disruption event, for which geochronological data are reported here for the first time. The first post-diversion terrace of the Thames also reaches this peninsula, the river having essentially re-joined its original valley before crossing the alignment of the modern coastline. This terrace passes beneath Clacton-on-Sea, where it includes the type locality of the Clactonian Palaeolithic Industry. The area of interest to this paper, in NE Essex and southern Suffolk, includes a number of interglacial and Palaeolithic sites, the data from which assist in constraining the chronostratigraphy of the sequence. In some cases, there has been uncertainty as to whether these sites represent pre-Anglian environments and hominin occupations, part of the palaeo-Thames sequence, or whether they are the product of later post-Anglian streams, formed after the Thames had migrated southwards. This paper compiles evidence from a wide range of recent sources, including developer-funded archaeological appraisal and citizen-science activities, to explore and update the evidence from sites at Ipswich, Upper Dovercourt and Thorpe-le-Soken, as well as a number of localities associated with the Clacton Channel Deposits (host to the type-Clactonian), amongst others. The resulting new data are placed within the wider context of the Quaternary fluvial archives in southern Britain, with a discussion of how disparate sources of information, including the work of citizen scientists, have contributed.

Taphonomic and technological analyses of Lower Palaeolithic bone tools from Clacton-on-Sea, UK

“…The Thames-Medway channel at Clacton can be traced for 3 km between foreshore exposures at Lion Point, Jaywick, in the southwest and Clacton Pier in the northeast (Fig. 1 ) 36 – 43 . The deposits have been investigated in archaeological excavations at Jaywick Sands in 1934 29 , Clacton golf course in 1969–1970 39 and in 1987 at the former Butlin’s holiday camp at Clacton 40 .…”

“…The deposits have been investigated in archaeological excavations at Jaywick Sands in 1934 29 , Clacton golf course in 1969–1970 39 and in 1987 at the former Butlin’s holiday camp at Clacton 40 . Warren identified three parallel channels, two of which (ii–vi, iii–iv) are younger than the channel (i–v) containing the Clactonian artefacts and the richest assemblages of Pleistocene vertebrates 43 , 44 . At several locations, the Pleistocene sediments are overlain by Holocene estuarine and freshwater deposits 40 , 43 .…”

“…Warren identified three parallel channels, two of which (ii–vi, iii–iv) are younger than the channel (i–v) containing the Clactonian artefacts and the richest assemblages of Pleistocene vertebrates 43 , 44 . At several locations, the Pleistocene sediments are overlain by Holocene estuarine and freshwater deposits 40 , 43 .

Figure 1 Map of the Pleistocene channels in the Clacton-Jaywick area, showing the findspots of the bone tools (adapted from Allen et al [ref.

…”

“…

Figure 1 Map of the Pleistocene channels in the Clacton-Jaywick area, showing the findspots of the bone tools (adapted from Allen et al [ref. 43 , Fig. 12]).

…”

“…Superficial post-depositional pitting and trampling striae present on some specimens Mary Leakey’s trenches at Jaywick 29 Light grey with varying amounts of orangey-brown iron staining. Cortical surfaces generally well-preserved with a few specimens exhibiting minor post-depositional pitting Channel iii–iv, Jaywick (Foreshore exposures of Last Interglacial (MIS 5e) channel-fill) Bones with characteristic white colour in mottled orange-grey silty clay with marine molluscs and reworked freshwater ostracods and molluscs probably derived from the nearby Hoxnian Clacton Channel deposits 43 Lion Point, Jaywick (Collected by Warren from foreshore exposures) Light brown–fawn–grey with orangey-brown iron staining. Occasional trampling striae and post-depositional pitting, including etching from plant roots.…”