Simon G. Lewis

Early Pleistocene human occupation at the edge of the boreal zone in northwest Europe

The dispersal of early humans from Africa by 1.75 Myr ago led to a marked expansion of their range, from the island of Flores in the east to the Iberian peninsula in the west. This range encompassed tropical forest, savannah and Mediterranean habitats, but has hitherto not been demonstrated beyond 45° N. Until recently, early colonization in Europe was thought to be confined to the area south of the Pyrenees and Alps. However, evidence from Pakefield (Suffolk, UK) at ∼0.7 Myr indicated that humans occupied northern European latitudes when a Mediterranean-type climate prevailed. This provided the basis for an ‘ebb and flow’ model, where human populations were thought to survive in southern refugia during cold stages, only expanding northwards during fully temperate climates. Here we present new evidence from Happisburgh (Norfolk, UK) demonstrating that Early Pleistocene hominins were present in northern Europe >0.78 Myr ago when they were able to survive at the southern edge of the boreal zone. This has significant implications for our understanding of early human behaviour, adaptation and survival, as well as the tempo and mode of colonization after their first dispersal out of Africa.

Deserted Britain: declining populations in the British Late Middle Pleistocene

This paper defines the potential reasons for low population levels in Oxygen Isotope Stages 6–4: climate, habitat preferences and sea level.

Hominin footprints from early Pleistocene deposits at Happisburgh, UK.

Investigations at Happisburgh, UK, have revealed the oldest known hominin footprint surface outside Africa at between ca. 1 million and 0.78 million years ago. The site has long been recognised for the preservation of sediments containing Early Pleistocene fauna and flora, but since 2005 has also yielded humanly made flint artefacts, extending the record of human occupation of northern Europe by at least 350,000 years. The sediments consist of sands, gravels and laminated silts laid down by a large river within the upper reaches of its estuary. In May 2013 extensive areas of the laminated sediments were exposed on the foreshore. On the surface of one of the laminated silt horizons a series of hollows was revealed in an area of ca. 12 m2. The surface was recorded using multi-image photogrammetry which showed that the hollows are distinctly elongated and the majority fall within the range of juvenile to adult hominin foot sizes. In many cases the arch and front/back of the foot can be identified and in one case the impression of toes can be seen. Using foot length to stature ratios, the hominins are estimated to have been between ca. 0.93 and 1.73 m in height, suggestive of a group of mixed ages. The orientation of the prints indicates movement in a southerly direction on mud-flats along the river edge. Early Pleistocene human fossils are extremely rare in Europe, with no evidence from the UK. The only known species in western Europe of a similar age is Homo antecessor, whose fossil remains have been found at Atapuerca, Spain. The foot sizes and estimated stature of the hominins from Happisburgh fall within the range derived from the fossil evidence of Homo antecessor.

The Upper Pleistocene deposits at Cassington, near Oxford, England

For much of the Middle and all of the Upper Pleistocene the Upper Thames valley has remained outside the limit of ice advance. The main agents of landform evolution have been the River Thames and its tributaries, which have cut down episodically and in so doing have abandoned a series of river terraces. This study reports the findings of an investigation into exposures in the deposits underlying the Floodplain Terrace at Cassington, near Oxford, England. The sequence exposed reveals a stratigraphy of basal, predominantly fine-grained, lithofacies overlain by coarser gravel lithofacies. The fluvial architecture of these deposits indicates a major change in fluvial style from a low-energy (meandering) to a high energy (braided) channel system. The flora and fauna from the lower fine-grained lithofacies display a marked change from temperate at the base, to colder conditions towards the top, indicating a close association between deteriorating climate and changing fluvial depositional style. Amino acid and luminescence geochronology from the basal fine-grained lithofacies suggest correlation with Oxygen isotope Stage 5 and hence it is argued that the major environmental change recorded at the site relates to the Oxygen-Isotope Stage 5-4 transition. Deposition of much of the overlying gravel sequence probably occurred during Oxygen isotope Stage 4, suggesting that the latter half of the Devensian may be less significant, in terms of fluvial landscape evolution in the Upper Thames valley, than was believed previously

The fluvial system response to abrupt climate change during the last cold stage: the Upper Pleistocene River Thames fluvial succession at Ashton Keynes, UK

Abstract The last interglacial–glacial cycle (125–10 ka BP) is characterised by numerous rapid shifts in global climate on sub-Milankovitch timescales, recorded in the ocean and ice core records. These climatic fluctuations are clearly recorded in those European terrestrial sedimentary sequences that span this time period without interruption. In the UK, only fragmentary Upper Pleistocene sequences exist, mainly within the fluvial archive of the major river systems such as the Thames. The response of the upper River Thames to abrupt fluctuations in climate is documented in the fluvial sediments beneath the Floodplain Terrace (Northmoor Member of the Upper Thames Formation) at Ashton Keynes, Wiltshire. A number of criteria are set out by which significant changes in the fluvial system may be established from the sedimentological, palaeoecological and geochronological information contained within the succession. The sedimentary succession is divisible into four facies associations, on the basis of their sedimentology and bounding surface characteristics. These represent distinct phases of fluvial activity at the site and allow changes in fluvial style to be inferred. Palaeoecological reconstructions from pollen analysis of peats within the sequence provides an indication of the nature and direction of Late Glacial environmental change and optically stimulated luminescence and radiocarbon dating methods provide chronological control on the sequence. These data suggest that major changes in fluvial style are recorded within the succession, which can be related to the climatic fluctuations that took place on the oxygen isotope stage 5a/4 transition (approximately 70 ka BP) and the Devensian Late Glacial climatic warm–cold–warm oscillation (13–11 ka BP). The changes in fluvial style are a result of variations in sediment supply to the river resulting from changes in slope stability, vegetation cover and cold-climate mass movement processes and variations in discharge regime caused by changes in precipitation patterns, snow cover, permafrost distribution and vegetation cover.

Pleistocene geology of the lower Severn valley, U.K.

Abstract The lower Severn valley contains a sequence of fluvial, glaciofluvial and glaciogenic deposits of Pleistocene age which is divided into two formations. Glaciogenic sediments are correlated with members of the Wolston Formation (Anglian). A new formation, the Severn Valley Formation, which consists of fluvial deposits, is defined. It is sub-divided into six members, the four oldest of which are considered in this paper. The oldest deposits in the lower Severn basin are the till and glaciofluvial outwash gravels of the Woolridge Member. The till is correlated with the Thrussington Member of the Wolston Formation which is correlated with the Lowestoft Formation of the Anglian Stage (Oxygen Isotope Stage 12). The oldest member of the Severn Valley Formation, the Spring Hill Member, is provisionally correlated with OI Stage 10. The Bushley Green Member represents deposition during OI Stages 9 and 8, the basal fossiliferous sediments (Bushley Green Fossil Bed) are correlated with OI Stage 9 by amino acid geochronology. The Kidderminster Station Member records a significant input of lithologies not seen in quantity in the higher members, and evidence is presented which suggests that this is a response to renewed glaciation in the upper basin. This glaciation was responsible for the deposition of the Ridgacre Formation of the Birmingham area. Amino acid geochronology and Chlorine-36 ages from erratic boulders show that the Kidderminster Station Member and Ridgacre Formation are of OI Stage 6 (Warthe) age. The basal deposits of the Holt Heath Member include the Stourbridge Fossil Bed, with a temperate fauna believed to be Ipswichian (‘last interglacial’, OI Substage 5e), and the Upton Warren Fossil Bed (OI Substage 5a). Most of the Holt Heath Member consists of outwash from an Irish Sea ice sheet which entered the Severn basin during the Late Devensian (OI Stage 2).

Contemporaneity of Clactonian and Acheulian flint industries at Barnham, Suffolk

New field evidence challenges an old-established fundamental of the Lower Palaeolithic sequence in Britain.

Early and Middle Pleistocene river systems in eastern England: evidence from Leet Hill, southern Norfolk, England

Pleistocene sediments at Leet Hill, southern Norfolk are examined in terms of their sedimentary structures, palaeocurrent indicators, clast and heavy mineral lithology and litho- and morphostratigraphic position. Colour of the quartzite and vein-quartz clasts is used to differentiate the Bytham and the Kesgrave sands and gravels, with the Bytham sands and gravels having a significantly higher proportion of coloured material. The Kirby Cane sands and gravels are the lower sedimentary unit and were deposited by the Bytham river, which drained a catchment extending into central England. At Leet Hill, erosion of the Kesgrave Sands and Gravels by the Bytham river has given the Kirby Cane sands and gravels a distinctive lithological assemblage. Trace clast lithologies suggest that the Kesgrave Sands and Gravels in the region of Leet Hill were deposited in a coastal location with an input from northern sources as well as southern and Welsh sources diagnostic of the Thames catchment. The glaciofluvial Leet Hill Sands and Gravels were deposited by outwash from the Anglian Scandinavian ice sheet. Initially the flow direction of the outwash was determined by the Bytham river valley, but this changed to a southerly direction once the valley had been infilled. This paper provides the first indication of the location of the boundary (Early Pleistocene coastline) between the fluvial Kesgrave Sands and Gravels and the marine equivalent reworked by coastal processes, and demonstrates the way the pre-glacial relief initially controlled patterns of glaciofluvial sedimentation during the early part of the Anglian glaciation. Copyright

Middle Pleistocene deposits at Frog Hall Pit, Stretton‐on‐Dunsmore, Warwickshire, English Midlands, and their implications for the age of the type Wolstonian

Organic sediment from Frog Hall Pit, near Coventry, has produced pollen, plant macrofossil, insect, ostracod and molluscan data indicative of the early part of a temperate episode in the Middle Pleistocene. The regional stratigraphy and clast lithological characteristics of the gravels underlying the temperate deposits show that the whole sequence at the site post-dates the major glaciation (the Wolstonian sensu Mitchell et al., 1973) of the Midlands. Amino-acid D/L ratios from molluscan shells give mean values of 0.24, which is consistent with an age in Oxygen Isotope Stage 9 and comparable with those from the Hoxnian Interglacial of East Anglia. This age-estimate for the Frog Hall organic deposit places a minimum age on the Wolstonian Glaciation of the Midlands in Oxygen Isotope Stage 10, and therefore close in time to the Anglian (Oxygen Isotope Stage 12) Cold Stage.

Mapping the human record: population change in Britain during the Early Palaeolithic

Abstract This chapter examines the changing human demography of Britain during the Lower and early Middle Palaeolithic using Palaeolithic handaxe densities in the Middle Thames and Solent rivers as proxies for relative population. Peak populations are suggested for Marine Isotope Stages (MISs) 13 and 11, and population decline is indicated after MIS 10. This data is compared to the individual site records for the early Middle Palaeolithic, where a similar pattern of decline in the number of sites is discernible. Differences between the British and mainland northwest European records may be explained by the changing palaeogeography of Britain. In particular, the progressive subsidence of the floor of the North Sea Basin made recolonisation of Britain during warm events increasingly difficult. Finally, models are put forward for interpreting population change in relation to the climatic record, the subsidence of the North Sea Basin and the changing ability of humans to withstand cold conditions.