Bytham River Research Articles

The contribution of Rob Westaway to the study of fluvial archives

Robert Westaway was a structural and hard-rock geologist who turned his attention to the study of Late Cenozoic fluvial archives, believing that the preservation of staircases of river terraces, particularly representing the Middle and Late Pleistocene, could only be explained in terms of crustal activity in response to surface processes, the latter affected by climatic change. His entry into this research area coincided with the realisation that such terrace sequences required surface or crustal uplift to have taken place over the time interval represented. Workers were unable to explain the observed amounts of uplift in terms of erosional isostasy, a process that could potentially have explained such one-way crustal movement. Westaway envisaged a mechanism by which mobile lower crust migrated to beneath uplifting areas, maintaining and reinforcing their uplift. The mechanism requires complex mathematics to explain it, as well as lending itself to mathematical modelling of the process, based on varying crustal properties and changes in the rates of surface processes in response to climatic fluctuation. Essentially the lower-crustal effect can be envisaged as a positive-feedback enhancement of erosional isostasy.It became apparent that Westaway's theories could explain geomorphological and sedimentary fluvial archives that were otherwise difficult to elucidate. Mantle-based erosional isostasy could not explain terrace staircases, for example. Many of these occur in regions that are tectonically inactive, and so cannot be attributed to neotectonic activity. A game-changer in terms of persuading the wider community came from the recognition of crustally ultrastable regions in which progressive long-timescale uplift has not occurred: Archaean cratons. Westaway's envisaged lower-crustal flow would not be expected in such regions, which have cold, brittle and immobile crust to its full depth. Ancient fluvial deposits are found close to modern valley-floor levels in such areas. Regions of younger Precambrian crust (Proterozoic) showing intermediate situations were subsequently identified. Other dilemmas could be resolved, such as the ‘back-tilting’ of the early-Middle Pleistocene Bytham River in the English Midlands, caused by its drainage crossing crustal blocks with different properties that have accordingly experienced differential uplift. Although glacio-isostasy, mostly seen in the effects of rebound since the Last Glacial Maximum (LGM), is largely accommodated in the mantle, and thus is reversed as a response to glacial loading and unloading, in areas of suitable crustal type there is evidently a small lower-crustal component that is less readily reversible.Westaway's important contribution has yet to be fully integrated into received wisdom in geomorphological and Quaternary circles, although much of it is now widely accepted and more will be explored and published in due course.

A revised terrace stratigraphy and chronology for the early Middle Pleistocene Bytham River in the Breckland of East Anglia, UK

The Bytham River was one of the major pre-Anglian (MIS 12) rivers of eastern England. Flowing from the Midlands to the East Anglian coast, it has been recognised at numerous sites by its distinctive lithological suite, containing significant quantities of quartzite, quartz and Carboniferous chert that originate from central England. In the Breckland of Suffolk and Norfolk, deposits of the Bytham River can be identified at 26 sites by this distinctive clast lithological composition. These sediments, referred to as the Ingham Formation, consist of a series of sand and gravel aggradations, which due to their differences in elevation can be interpreted as at least four early Middle Pleistocene terrace remnants of the former river, and a final phase of deposition along the river valley prior to its destruction. This paper reports on recent fieldwork at six of these sites, which through stratigraphic and lithological analyses, together with new Electron Spin Resonance age estimates, contribute to a revised geological framework for the Bytham River as represented in the Breckland. These sites can be attributed to the four lowest fluvial aggradations, with the lowest and youngest of these aggradations shown to be early Anglian in age. The river was subsequently overrun by Anglian ice during Marine Isotope Stage 12. This revised geological and chronological interpretation provides an important framework for understanding the Lower Palaeolithic artefacts that have been found within these gravel aggradations, and contributes to the understanding of the human occupation of north-west Europe during the early Middle Pleistocene.

Cultural mosaics, social structure, and identity: The Acheulean threshold in Europe

The period between 600 and 400 ka is a critical phase for human evolution in Europe. The south and northwest saw a dramatic increase in sites, the spread of handaxe technology alongside bone and wooden tool manufacture, efficient hunting techniques, and the use of fire. Lithic assemblages show considerable variation, including the presence/absence of handaxes and tool morphology. To explain this variation, we propose the Cultural Mosaic Model, which suggests that there is a range of expressions of the Acheulean, with local resources being instrumental in creating distinct material cultures with or without handaxes. We argue that if typologically and technologically distinct assemblage types are regionally distributed, chronologically separated, and persistent over time, then they are unlikely to be caused purely by raw material constraints or functional variation but rather reflect populations with different material cultures. We initially assess the model using British data. Britain was a northwestern peninsula of Europe, and oscillations in climate led to episodic occupation. The terraces of the pre-MIS 12 Bytham River provide a framework for dating occupation to MIS 13 and 15, while during MIS 11, archaeological sites with rich environmental records can be dated to substage level. We suggest there are six chronologically and typologically distinct assemblage types that reflect a series of population incursions into Britain. We review the broader European lithic record, which is consistent with the Cultural Mosaic Model. In developing the model, we suggest that during stable climate, localized cultures developed, while climatic change led to shifts in population, with increased knowledge exchange and gene flow. We suggest that group expression through material culture was an important stage in social development by promoting group cohesion, larger group size, better cooperation, improved knowledge transfer, and enabling populations to survive in larger foraging territories in northern Europe.

Palaeolithic archaeology of the Bytham River: human occupation of Britain during the early Middle Pleistocene and its European context

ABSTRACTThe Early and early Middle Pleistocene archaeological record in Britain from c. 900 to 500 ka marks a critical shift in human occupation of northwest Europe, from occasional pioneer populations with simple core and flake technology to more widespread occupation associated with the appearance of Acheulean technology. Key to understanding this record are the fluvial deposits of the extinct Bytham River in central East Anglia, where a series of Lower Palaeolithic sites lie on a 15 km stretch of the former river. In this paper we present the results of new fieldwork and a reanalysis of historical artefact collections of handaxes and scrapers to: 1) establish the chronostratigraphic context of the Bytham archaeological record; 2) examine variability in lithic artefact typology and technology through time; and 3) explore the implications for understanding variation in lithic technology in the European record. Six phases of occupation of Britain are identified from at least marine isotope stage (MIS) 21 to MIS 13, with the last three phases characterised by distinctive lithic technology. We argue that this relates to the discontinuous occupation of Britain, where each phase represents the arrival of new groups derived from different European populations with distinctive material culture.

Early Middle Pleistocene drainage in southern central England

AbstractThe fluvial sequences of the Milton and the Letchworth formations in the south Midlands of England and neighbouring regions represent at least two pre-existing rivers, the Milton and Brigstock streams, underlying Middle Pleistocene glacial sediments. The Milton Formation includes sand sourced from the Midlands bedrock. This implies that both streams were aligned in a northwest to southeast direction. This direction parallels the contemporaneous courses of the rivers Thames and Trent, the former turning towards the east and northeast to enter the North Sea. Their alignments indicate that the Milton and Letchworth streams formed left-bank tributaries of the Thames, joining the river in Hertfordshire and Essex, as illustrated in the article. This reconstruction has important implications for the interpretation of the proto-Soar river of the south Midlands, represented by the Baginton Formation. Although originally thought to represent a late Middle Pleistocene line, this southwest to northeast aligned system was reinterpreted as the headwaters of a pre-Anglian ‘Bytham river’, a1ligned towards East Anglia. However, recent work has shown that this river could not have existed in the pre-Anglian since there is no link between the Midlands and East Anglian spreads. Recent re-recognition that the Baginton Formation deposits do represent a later, post-Anglian drainage line is reinforced by the identification of the Milton and Letchworth streams, whose catchments occupied the area later drained by the proto-Soar. Overall, the main drainage alignment in southern England during the pre-Anglian period was dominated by northwest–southeast-draining consequent rivers adjusted to the regional geological dip. After widespread drainage disruption caused by the Anglian glaciation, northeast–southwest-orientated subsequent streams eroded frost-susceptible clay bedrock under periglacial and permafrost conditions, and beheaded the courses of some of the older consequent streams.

Late Middle Pleistocene glaciofluvial sedimentation in western Norfolk, England

AbstractInvestigation of landforms on the eastern margin of the East Anglian Fenland basin has demonstrated that they represent a series of glaciofluvial delta-fan and related sediment accumulations (the Skertchly Line) deposited at the margin of an ice-lobe that entered the depression. This ‘Tottenhill glaciation’ dated to ca 160 ka, or the late Wolstonian (= late Saalian) Stage, is equivalent to that during the Netherlands' Drenthe Substage (Marine Isotope Stage 6). Of these landform complexes, an additional site at Shouldham Thorpe, previously nominated as the stratotype for deposits linked to a pre-Anglian Stage, Midlands'-derived Ingham/‘Bytham river’, has now been studied. Examination of the internal structure and form of the feature, using ground-penetrating radar (GPR), supported by section logging, borehole records, local landscape morphology and previous description, together indicate that the deposits rest on an eroded surface of Lowestoft Formation diamicton (Anglian Stage) and must therefore be of post-, rather than pre-Anglian age. The investigations indicate that the Shouldham deposits were laid down as a glacio-marginal subaerial (‘terminoglacial’) fan at the ice-front. In common with other sequences in the Skertchly Line complexes, deposition at Shouldham Thorpe was accompanied by minor ice-front movement, this fan potentially being deposited before retreat to the Tottenhill locality. The implications of the results are discussed.

The Bytham river reconsidered

The English Midlands is one of the most important regions for British Pleistocene geology. The Middle Pleistocene glacial sediments of the region, termed the Wolston Formation, overlie deposits of a pre-existing river system, the Baginton Formation. The latter are characteristically composed of quartz-rich sediment derived from underlying Triassic bedrock. This SW–NE aligned proto-Soar system was overridden by the Wolstonian ice. Its lack of terraces or discrete sedimentary units implies that the river can only have existed for a limited period. The deposits accumulated during a period of climate change from boreal (?interstadial) to subarctic conditions. A reinterpretation of these sediments as the headwaters of a pre-Anglian ‘Bytham river’, aligned towards East Anglia across the Fenland, where they were linked to the Ingham Formation deposits, found favour for two decades. This was especially so when the Wolston Formation sediments were reassigned to the earlier, Anglian Stage. However, recent work has shown that the ‘Bytham river’ could not have existed in the form suggested by some authors since pre-Anglian-age fluvial sediments are absent from the eastern Fenland margin, except possibly certain deposits at High Lodge, Suffolk. Therefore a re-examination of the evidence is required.It is concluded that the Wolstonian glaciation (late Saalian, Marine Isotope Stage [MIS] 6) indeed post-dates that during the Anglian Stage (Elsterian, MIS 12). In addition, it appears that the Baginton (proto-Soar) stream, as originally conceived, almost certainly did not exist before the early Wolstonian (early Saalian) Stage, following a significant period of fluvial incision. Rather than being aligned towards East Anglia, the substantial proto-Soar flowed into south Lincolnshire and thence potentially to the North Sea via the Wash and the Silver Pit depression. By contrast, the pre-Anglian Ingham Formation deposits of central East Anglia were almost certainly deposited by a separate proto-Trent river that drained the East Midlands over an extended period as a left-bank Thames' tributary. Together these conclusions reinforce the view that the main drainage alignment in southern England during the pre-Anglian period was NW to SE parallel to the regional tilt of the landmass.

The conservation of unconsolidated Pleistocene strata: an experiment at Wood Farm Pit, Bubbenhall, Warwickshire, UK

Abstract Wood Farm Pit, Bubbenhall, Warwickshire, central England, was one of a complex of sand and gravel quarries within unconsolidated Middle Pleistocene fluvial and glaciogenic sediments of the Baginton and Wolston formations. These strata document the development of the pre-Anglian Bytham River and its eventual destruction during the Anglian glaciation. They have yielded a freshwater and terrestrial fossil biota and Lower Palaeolithic handaxes, and demonstrate well-preserved sedimentary structures. These features underline the value of the local Middle Pleistocene sites as scientific and educational resources. The Warwickshire Geological Conservation Group introduced an experimental soft-sediment conservation scheme at Wood Farm Pit during 2005–2007. This involved designing, installing and monitoring a screen to protect a representative geological exposure. The structure proved highly effective in terms of low cost, ease of installation, protection of the face and allowing rapid re-exposure. The experiment was halted by flooding within the quarry, following high rainfall.

The British Lower Palaeolithic of the early Middle Pleistocene

The archaeology of Britain during the early Middle Pleistocene (MIS 19–12) is represented by a number of key sites across eastern and southern England. These sites include Pakefield, Happisburgh 1, High Lodge, Warren Hill, Waverley Wood, Boxgrove, Kent's Cavern, and Westbury-sub-Mendip, alongside a ‘background scatter’ lithic record associated with the principal river systems (Bytham, pre-diversion Thames, and Solent) and raised beaches (Westbourne–Arundel). Hominin behaviour can be characterised in terms of: preferences for temperate or cool temperate climates and open/woodland mosaic habitats (indicated by mammalian fauna, mollusca, insects, and sediments); a biface-dominated material culture characterised by technological diversity, although with accompanying evidence for distinctive core and flake (Pakefield) and flake tool (High Lodge) assemblages; probable direct hunting-based subsistence strategies (with a focus upon large mammal fauna); and generally locally-focused spatial and landscape behaviours (principally indicated by raw material sources data), although with some evidence of dynamic, mobile and structured technological systems. The British data continues to support a ‘modified short chronology’ to the north of the Alps and the Pyrenees, with highly sporadic evidence for a hominin presence prior to 500–600 ka, although the ages of key assemblages are subject to ongoing debates regarding the chronology of the Bytham river terraces and the early Middle Pleistocene glaciations of East Anglia.

Quaternary vertical crustal motion and drainage evolution in East Anglia and adjoining parts of southern England: chronology of the Ingham River terrace deposits

Prior to its disruption during the Anglian glaciation (MIS 12), the Ingham or Bytham River used to flow eastwards across central England and East Anglia into the southern North Sea. It thus had a much larger catchment than any extant river system in Britain; its headwaters may well have been as far away as North Wales and/or NW England. Terrace deposits of this former river system crop out across East Anglia and, as for any other river, can be used to investigate uplift, landscape evolution and the physical properties of the underlying continental crust. However, such an investigation has hitherto been hampered by inconsistencies between different authors' terrace schemes; furthermore, and controversially, one such scheme has formed the basis for the inference that the region was affected by a pre‐Anglian (MIS 16) glaciation. By re‐examining the raw data, the Ingham River deposits are shown to be disposed in three terraces, inferred to date from MIS 16, 14 and 12. The evidence previously attributed to pre‐Anglian glaciation is associated with the youngest of these terraces, and thus marks the MIS 12 (i.e. Anglian) glaciation; the argument for glaciation of the region in MIS 16 is thus an artefact of previous miscorrelation of the terrace deposits. It is inferred that development of the very large Ingham River was synchronous with decapitation of the former ‘Greater Thames’, or ‘High‐level Kesgrave Thames’ river, some time between MIS 18 and MIS 16. Uplift histories at representative localities across East Anglia have been modelled using composite data sets, combining the terrace deposits of the Ingham River and of the post‐Anglian rivers Lark and Waveney. The sites modelled are typefied by much faster uplift in the early Middle Pleistocene than in the late Middle Pleistocene; this effect is shown to be a consequence of the relative thinness (no more than ∼7–8 km thick) of the mobile lower‐crustal layer, itself a consequence of the low surface heat flow in the London Platform crustal province. The post‐Early Pleistocene uplift tapers eastward, consistent with the observed downstream convergence of the Ingham and Waveney terraces, and is close to zero near the modern coastline around Lowestoft and Great Yarmouth. Stratigraphic relationships between the Ingham terrace deposits and temperate‐stage marine and terrestrial deposits in this coastal area allow sites to be dated; thus, Pakefield and Corton date from MIS 15, whereas Norton Subcourse dates from MIS 17. The oldest known Lower Palaeolithic sites in the region, characterized by flake artefacts, are Pakefield (MIS 15) and Hengrave (?MIS 14); younger pre‐Anglian sites that have yielded handaxes and/or fossil material of the water vole Arvicola cantiana date from MIS 13. The minimal vertical crustal motion in this coastal area, where temperate‐stage deposits from different climate cycles crop out close to present‐day sea level, does not imply high crustal stability; instead, it indicates a ‘hinge zone’ between the uplifting hinterland and the subsiding depocentre in the southern North Sea.

Insect faunas associated with palaeolithic industries from five sites of pre-Anglian age in central England

Fossil insect faunas are described from five sites where organic silts fill ancient river channels. Two of the sites (Waverley Wood and Brooksby) are in the English Midlands and the other three of them (High Lodge, Happisburgh and Pakefield) are in East Anglia. Their stratigraphical contexts can be shown to pre-date the Anglian (Elsterian) Glaciation. All these localities are associated with palaeolithic implements. Three of them, Waverley Wood, Brooksby and High Lodge, are riverine deposits related to the pre-glacial Bytham River valley. The channel at Happisburgh probably dates from the same period though it was probably not part of the main Bytham River valley. The insect fauna from the pre-glacial channel at Pakefield suggests that it is not of the same age as the others. The insect assemblages include exotic species that enable stratigraphical correlations to be made with other sites in central England. They provide detailed information on the local environment and regional climate at the time when palaeolithic peoples were living in central England.

Dating the earliest lowland glaciation of eastern England: a pre-MIS 12 early Middle Pleistocene Happisburgh glaciation

This paper outlines the evidence for the Happisburgh Glaciation—the first Middle Pleistocene glaciation of lowland eastern England and the adjacent margins of the North Sea Basin. We propose that this glaciation occurred during a pre-Elsterian/Anglian (MIS 12) cold stage based on evidence of clasts of till, erratics and heavy minerals from the third youngest terrace of the ‘pre-glacial’ Bytham River in southern Norfolk. The heavy minerals show a progressive increase in glacially sourced materials from the bottom to the top of the Bytham River third terrace sediments. The till clasts are correlated with the extensive deposits of the Happisburgh Formation on the basis of their colour, heavy minerals and particle size properties. Thus, the Happisburgh Glaciation occurred during the accumulation of the Bytham River terrace deposits and prior to MIS 12, when the Bytham River system was destroyed by the Anglian glaciation. In the absence of any geochronology or robust biostratigraphy, the age of the Happisburgh Glaciation is estimated by the synchronisation of the pattern of large-scale river activity with patterns of Milankovitch-forced global climate change. On this basis, and assuming the British Ice Sheet acted in phase with global patterns of ice volume, the Happisburgh Glaciation is considered to have occurred during MIS 16 and be equivalent of the Don Glaciation of eastern Europe.

Early and early Middle Pleistocene river, coastal and neotectonic processes, southeast Norfolk, England

This paper investigates the interaction between coastal and river processes and neotectonics, prior to glaciation of northern East Anglia, eastern England. The study is based on results obtained from two boreholes drilled into the plateau of southeast Norfolk, between the Yare and Waveney valleys. Diagnostic sedimentary and lithological indicators from core samples are used to describe the main lithological units, and to compare them with the type sites of the Norwich Crag, and members of the Bytham Sands and Gravels, and Corton Formation. The results provide evidence for coastal sedimentation in the Early Pleistocene, when the Norwich and Wroxham Crags were deposited, and evidence to establish links between the coastal deposits and the contemporary river systems. The Norwich Crag received only suspended sediment from low energy rivers, whereas the Wroxham Crag received bedload transported from the whole catchment. Neotectonic subsidence within the region is proposed to explain the transgression of the Wroxham Crag across the Norwich Crag. The succeeding stratigraphical units are fluvial sediments of the Bytham river, which was the major river draining Midland England during the Middle Pleistocene. These sediments are located in a valley cut into the Crag, indicating uplift between the deposition of the coastal and river deposits. After their deposition, the whole region was overridden by glaciers that deposited the sediments of the Corton and Lowestoft formations, and shifted the Bytham river to a more southerly route.

Pre-Anglian fluvial and coastal deposits in Eastern England: lithostratigraphy and palaeoenvironments

Clast lithology and derived microflora are used to provide a basis for correlating pre-Anglian fluvial and coastal deposits in eastern England and to provide a lithostratigraphic framework for these Early and early Middle Pleistocene sediments. Three fluvial systems are recognised. (i) The Thames, which drained an area from Wales through midland England to the Thames basin and southern East Anglia. The catchment was truncated over the period concerned and the western headwaters diverted to other river systems. (ii) The Bytham river which drained midland England and the southern Pennines and reached the southern North Sea delta in the region of north central East Anglia. This river extended its catchment over the period concerned. (iii) The Ancaster river which drained the southern Pennines and received sediment from northeast England. Each of these catchments contributed sediment to the southern North Sea delta/estuary and contributed to the lithologies of the Red, Norwich, and Wroxham Crag formations. The lithostratigraphic subdivisions are based on the fact that: (i) the Pliocene and Early Pleistocene rivers and the equivalent Red and Norwich Crags are characterised by far-travelled microflora which was transported in suspension and a locally derived clast assemblage transported as bedload , and (ii) the later Early and early Middle Pleistocene rivers and the equivalent Wroxham Crag are characterised by a far-travelled microflora and a far-travelled clast assemblage. Variations in the amount and composition of far-travelled materials is determined by the relative importance of the three river systems. This provides a basis for identifying different formations of the Thames river sediments (older Sudbury Formation and younger Colchester Formation) and different members of the Wroxham Formation (Dobb's Plantation Member: local material with minor components of Thames and Ancaster river sediments; How Hill Member: local material with major components of Thames and Ancaster river sediments; Mundesley Member with major components of Bytham river sediments). These lithostratigraphic units are related to established North European biostratigraphy and Oxygen Isotope stratigraphy. The factors forcing the changes in river energetics are explained in terms of the relative importance of geomorphic processes operating within the river catchments determined by the patterns of Milankovitch orbital forcing .

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 © 1999 John Wiley & Sons, Ltd.

Pre-Anglian gravel deposits of the River Thames and its tributaries between Goring and Cromer

On the basis of gravel composition, the earliest evidence of a Thames drainage system that extended into East Anglia is in the Norwich Crag. An influx of quartz into the high level pebble gravels of the middle Thames is traced across Essex into the Creeting Sands in the Norwich Crag near Ipswich. Another influx of far-travelled material entered the Thames system in Westland Green times, and Thames gravels, incorporating quartz-rich far-travelled material, form the Kesgrave Sands and Gravels in Essex and Suffolk. Gravels of Kesgrave type are traced northward in East Anglia to the north Norfolk coast, but their presence in Norfolk is often masked by mixing with quartzite-rich gravels of the Bytham River, which was confluent with the Thames near Bury St Edmunds, or by incorporation in the Weybourne Crag, which is largely of northern derivation. Distinctive Kesgrave components, in particular cherts from the Lower Greensand of the Weald, are, however, widely present in Norfolk and confirm the passage of the Thames into this area. The onset of Kesgrave sedimentation, post-dating the Westleton Beds and predating the Weybourne Crag, provides an important stratigraphic datum in the Plio-Pleistocene sequence in East Anglia.

Pre-Anglian fluvial and Anglian glaciogenic sediments, Knettishall, Suffolk, England

A sequence of pre-Anglian fluvial sediments and Anglian glacial and glaciofluvial deposits are described from Knettishall in north central Suffolk. The pre-Anglian fluvial sediments, the Knettishall sands and gravels, are a member of the Ingham Formation, a constituent of the Bytham sands and gravels. These are a suite of quartzite and quartz-rich deposits formed by an easterly flowing river which drained from the English Midlands into central East Anglia where it was a tributary of the ancestral River Thames or, at a later stage, the River Rhine. The Anglian glaciogenic sediments comprise the brown, sandy Starston Till (North Sea Drift Formation), the chalky, olive-coloured, clayey Lowestoft Till (Lowestoft Formation) and the Coney Weston sands and gravels. Clast lithologies and sand mineralogy provide a basis for differentiating between the pre-Anglian and Anglian sediments and determining their provenance. In addition to elaborating the history of the pre-glacial Bytham river, the site extends the distribution of the Scandinavian glaciogenic sediments in Eastern England and confirms the contemporaneity of Scandinavian and Scottish glaciers during the Anglian Stage.

Major river systems of central and southern Britain during the Early and Middle Pleistocene

ABSTRACTCentral and southern Britain was drained by two main river systems during the larger part of the Early and Middle Pleistocene: the Thames and Bytham rivers. Evidence for these rivers and their Quaternary history is represented by their sediments (the Kesgrave and Bytham Sands and Gravels, respectively), the geomorphological position of the sediments, biostratigraphy and amino acid geochronology. Evidence from the earlier parts of the Early Pleistocene (Tiglian C4b and earlier) indicates low‐energy river systems and marine conditions over much of East Anglia. For most of the Early Pleistocene (Tiglian C4c to the Cromerian Complex) the ancestral Thames was the main river with, at its maximal extent, a catchment that extended into Wales, and across East Anglia and what is now the North Sea, to join the ancestral Rhine. During this period, glaciers in the uplands of Wales and periglacial mass movement elsewhere supplied material to the catchment and it was at this time that the bulk of the sorted Quaternary ssediments of lowland Britain were deposited. The Bytham river system has no successor because the landscape now in existence has been fundamentally altered by glacial erosion. This catchment drained most of Midland England and joined the Thames in central East Anglia. Initially, the Bytham river was a tributary of the Thames, but over time it extended its catchment and at the beginning of the ‘Cromerian Complex’it became the main river of southern Britain. With the Anglian Glaciation (01 Stage 121, the Bytham river was destroyed and the Thames was diverted to its present route through London.