East Anglia

Non-technical summary

The East Anglia NSPRMF study area extends from The Wash to Clacton-on-Sea and includes areas of seabed offshore from the earliest Lower Palaeolithic sites in northern Europe (Pakefield and Happisburgh), as well as the earliest submerged archaeological site in Europe (Area 240 in the PalaeoYare river catchment).

Key deposits that have been the focus of research in the East Anglia NSPRMF study area include sands, gravels, calsys, silts and peats associated with the PalaeoYare river, and silts, clays and peats of the Brown Bank Formations. Attention has also been given to locating and mapping the offshore extensions of the archaeologically significant deposits at Pakefield and Happisburgh.

Many of the archaeological finds from the East Anglia NSPRMF study area are associated with the submerged PalaeoYare which is an offshore extension of the River Yare in Norfolk. Over 100 individual bone fragments have been discovered, including straight-tusked elephant, woolly mammoth, woolly rhinoceros, steppe bison, giant deer, red deer and horse, indicating the region was once inhabited by a diverse range of mammals. Significant numbers of Middle Palaeolithic artefacts have also been recorded from deposits associated with the PalaeoYare, some of which are fresh and intact suggesting they are in situ and haven’t been reworked indicating people were active in and around the PalaeoYare.

The earliest recorded human activity in the PalaeoYare is associated with riverine deposited dated to approximately 200,000 years ago. Human active in the now offshore zone of the Yar, likely ceased as sea-levels rose and the region drowned during the last interglacial period (123,000 years ago). However, there is evidence for reactivation of the river channels during the subsequent episode of sea-level fall during subsequent periods of the Palaeolithic and Mesolithic artefacts have been found within a younger, channel. This suggests repeated occupation of the PalaeoYare over repeated glacial -interglacial cycles.

During the early parts of the last glacial period (115,000 to 90,000 years ago), as sea levels began to fall, the wider East Anglia region would have become a shallow marine embayment and fine-grained silts and clays of the Brown Bank Formation were deposited. Marine processes would have dominated during deposit which has been dated to between approximately 82,000 and 58,000 years ago. However, assessment of palaeoenvironmental remains from these deposits suggest at times sea levels fell and there is potential for human occupation along the margins of this embayment, therefore understanding its palaeogeography is important in the context of human migration pathways from Europe to Britain.

As sea-level continued to fall during the Late Glacial period, lowered sealevels saw the formation os complex drainage network of river channels fringed by peat and organic deposits formed. This riverine/wetland environmental was identified during investigations in support of the Norfolk Vanguard and Norfolk Boreas offshore wind farms and the peat is estimated to cover an area of approximately 85 km² making it the most extensive, near continuous, palaeoenvironmental record in the southern North Sea. Radiocarbon dating indicates this landscape existed between 12,500 and 9,750 years BP meaning this area of the southern North Sea was suitable for occupation for a period of approximately 3,000 years, before the region was inundated by post-glacial sea-level rise.

Stratigraphy, chronology, landscapes and palaeogeography

East Anglia is a key region with international significance when considering prehistory (Cohen et al. 2012). The earliest records of Lower Palaeolithic archaeology from northern Europe are associated with terrestrial deposits on the margins of the North Sea basin in East Anglia, most notably from Pakefield (Parfitt et al. 2005) and Happisburgh (Parfitt et al. 2010; Ashton et al. 2018). East Anglia is also home to one of the earliest submerged prehistoric sites at Area 240, a marine aggregate licence area located 11 km off the coast of Norfolk. Area 240 is one of the most northerly Middle Palaeolithic sites in northwest Europe and of primary archaeological importance for defining Middle Palaeolithic potential in the southern North Sea basin (Tizzard et al. 2014).

The discoveries at Pakefield and Happisburgh, as well as Area 240 prompted acquisition of geophysical, stratigraphic, palaeoenvironmental and chronological data in key areas (Pakefield, Happisburgh, Great Yarmouth and Area 240) funded by the Aggregate Levy Sustainability Fund (ALSF) as part of the Seabed Prehistory (Wessex Archaeology 2008b; 2008c; 2011a) and Regional Environmental Characterisation (Limpenny et al. 2011) projects, and through the Ancient Human Occupation of Britain (AHOB) and Pathways to Ancient Britain (PAB) projects in collaboration with Historic England (Ashton et al. 2018) (Table 8).

A considerable amount of data was collected to support the management and mitigation of marine aggregate Licence Area 240 and the associated aggregate licence areas making up the East Anglia block (Tizzard et al. 2014; 2015). Between 2008 and 2013, Wessex Archaeology undertook a series of multi-disciplinary projects in order to understand the palaeogeography and archaeology of the area and to improve the future management of the potential effects of aggregate dredging on the marine historic environment. The Seabed Prehistory: Site Evaluation Techniques (Area 240) project was undertaken between 2008 and 2011 (Wessex Archaeology 2011a), and it included the acquisition and interpretation of geophysical data, geotechnical data, seabed sampling, vibrocoring, palaeoenvironmental assessment, analysis and dating. In 2011, a programme of archaeological monitoring of aggregate dredging within Licence Area 240 and its subsequent processing in Holland was undertaken (Wessex Archaeology 2011b). The project trialled methods of bulk sampling the seabed using standard aggregate dredging plant in order to intercept and evaluate artefacts, and evaluate the presence/absence, distribution, character, quality and preservation of Palaeolithic artefacts in Licence Area 240. The results were used to design an appropriate monitoring programme that considers the preservation and significance of the artefactual material recovered.

Development-led research undertaken to support the offshore wind farm sector has also provided geophysical, lithostratigraphical, palaeoenvironmental and chronological data to help refine: lithostratigraphic and chronological frameworks; map palaeogeography; and, reconstruct palaeoenvironments (Wessex Archaeology 2015b; 2018a; 2018b; 2018c; 2018d; 2018e; 2018f; 2018g; 2019a; 2019b; Eaton et al. 2020). Archaeological prospecting was also undertaken at Brown Bank, directly adjacent to the East Anglia NSPRMF study area (Missiaen et al. 2021).

Table 8  Publicly available projects and published research since 2009 – East Anglia

The East Anglia study area has only experienced one glacial advance during the Pleistocene (Anglian; MIS 12) meaning palaeolandscape features from periods of low relative sea level are more likely to be preserved here than further north (e.g. North of The Wash), where they have been removed or reworked by the complex interplay of glacial, periglacial and fluvial processes operating in response to complex ice sheet history during the Middle Pleistocene. Any surviving Pleistocene deposits may have been reworked or redeposited to a certain extent by fluvial processes or marine processes (Cameron et al. 1992), but there is still high potential for them to survive at or below the seabed which is reflected in the archaeological record.

The Quaternary succession of the seabed offshore of East Anglia is typically relatively thin in nearshore areas with bedrock subcropping at shallow depths (0.5 m) (Wessex Archaeology 2008c) when compared to offshore where it infills the North Sea basin (Cameron et al. 1992), although research is starting to indicate that locally there may be infilled palaeochannels which contain thicker sequences of Quaternary deposits (e.g. Ashton et al. 2018). The stratigraphy of the East Anglia region comprises components of the Early to Middle Pleistocene deltaic sequence (pre-Anglian glaciation) and the Middle Pleistocene to Holocene glacigenic sequence (post-Anglian glaciation) (Stoker et al. 2011).

The oldest deposits likely to be encountered in the East Anglia Study area belong to the Westkapelle Ground Formation which are located near to the present-day Norfolk coast (Wessex Archaeology 2008b) and have been mapped extending up to 20 km offshore (Cameron et al. 1992). The Westkapelle Formation is Praetiglian and Tiglian in age (2.3-1.6 Ma) and therefore predates the earliest currently known occupation of Britain. Westkapelle Ground Formation is overlain by Yarmouth Roads Formation but it is often difficult to differentiate between them on seismic data or through core descriptions (Limpenny et al. 2011).

The earliest deposits of known archaeological interest belong to the Yarmouth Roads Formation which are non-marine sands with clay beds laid down in a fluvial to intertidal setting during the early Pleistocene prior to the Anglian glaciation (MIS 12). Yarmouth Roads Formation is considered to be broadly contemporaneous with terrestrial deposits belonging to the archaeologically significant Cromer Forest-Bed Formation (CF-bF) recorded on the foreshore and in the nearshore zone off Happisburgh (Lewis et al. 2019). OSL dating of Yarmouth Roads Formation sediments has returned dates of 577±65 ka (MIS 15) (Wessex Archaeology 2008b) and 735±134 ka (MIS 19) (Tizzard et al. 2015) suggesting deposition during the Cromerian (MIS 13-21).

Lewis et al. (2019) describe the palaeoenvironment at Happisburgh (Site 1) at the time of occupation (Cromerian; MIS 13) as a river floodplain with an active channel that was abandoned creating a floodplain lake fringed by marginal swamp environments. These channel deposits have been traced offshore into the nearshore zone but their preservation further offshore is expected to be lower as the overlying glacial deposits that protect the deposits onshore have been completely removed and they occupy elevations higher than the present day seabed (Wessex Archaeology 2008b; Ashton et al. 2018).

Given the archaeological importance of channel and floodplain deposits at Pakefield and Happisburgh (Parfitt et al. 2005; 2010; Lewis et al. 2019), a geophysical survey in the nearshore area of both Pakefield and Happisburgh was undertaken as part of the Seabed Prehistory project with the aim of tracing deposits and palaeolandscape features of interest offshore (Wessex Archaeology 2008c). The results identified Westkapelle Ground Formation and Yarmouth Roads Formation overlain by modern marine seabed sediments and CF-bF was not identified. However, the survey extent was restricted and there is potential for CF-bF to outcrop at seabed which has been proven through recent dive surveys (Ashton et al. 2018)

Channels within the upper parts of Yarmouth Roads Formation have been identified offshore. Eaton et al. (2020) map three northward-draining valleys ~ 80 km offshore within the Yarmouth Roads Formation. The relative age and relationship of these channels with those onshore at Pakefield and Happisburgh, or with the Pre-Anglian course the Bytham and Ancaster rivers (Rose et al. 2001; 2002; Rose 2009) is unknown and there is a need to correlate Early Pleistocene stratigraphy onshore-offshore in the East Anglia region to fully understand the archaeological significance of Yarmouth Roads Formation.

A large, multi-phase, E-W trending, braided channel feature has been identified offshore of Harwich Harbour (Dix and Sturt 2011). This channel is truncated by tunnel valleys interpreted to have formed in the Anglian period (MIS 12) and its incision therefore dates to the Early Pleistocene although radiocarbon and OSL dates from vibrocores within the channel suggest it was at least reoccupied during the Late Pleistocene to Early Holocene (Dix and Sturt 2011). Based on its location, the channel has been correlated to the High Halstow/Belfairs/Mayland Terrace Formations of the Medway which have been relatively dated to MIS 18 (Cromerian) (Westaway et al. 2002). This river system may therefore have been active during the period of earliest human occupation of Britain (Parfitt et al. 2005). Geophysical investigations undertaken in support of the East Anglia ONE OWF identified a buried palaeochannel extending from the mouth of the River Deben which was interpreted as a tributary of the pre-Anglian channel offshore of Harwich (Wessex Archaeology 2015b).

The seabed offshore of East Anglia was directly affected by glaciation during the Anglian (MIS 12) when ice extended into the southernmost North Sea. During subsequent glacial episodes, ice sheets terminated further north so did not directly affect the region. The exact southern extent of the Anglian glaciation is debatable. However, bathymetric data suggests part of the Anglian ice sheet may have extended as far south as offshore from Felixstowe and Dix and Sturt (2011) argue for an Anglian glacial origin for over-deepened valleys (tunnel valleys) identified within the Outer Thames estuary. Investigations at the Norfolk Vanguard and Norfolk Boreas OWFs identified over-deepened valleys infilled with high strength clays that are consistent with Swarte Bank Formation tunnel valleys identified elsewhere in the southern North Sea (Graham et al. 2011). These valleys were also identified in the northern parts of the East Coast REC study area (Limpenny et al. 2011).

The PalaeoYare fluvial system extends from the lower reaches of the present-day River Yare where it drains into the North Sea through Breydon Water in Great Yarmouth, to approximately 35 km offshore (Tizzard et al. 2014; 2015). Initial formation of the river system is suggested to have occurred during the Anglian period when extensive landscape remodelling and drainage reorganisation took place as the ice sheet advanced to its most southerly position. The earliest sediments infilling the submerged PalaeoYare are fine-coarse sand and gravel interpreted to have formed in a cold-climate glaciofluvial environment. Outside of the main channel, these deposits form a floodplain which is overlain in places by fine-grained sediments (Wessex Archaeology 2008b) and show evidence of oxidation and subaerial exposure (Tizzard et al. 2015). It is these floodplain deposits that preserve the important Middle Palaeolithic assemblage.    

A chronological framework for Area 240 has been established through OSL dating (Wessex Archaeology 2008; 2011; Limpenny et al. 2011) returning ages between 283 ± 56 ka (MIS 9/8) to 175 ± 23 ka (MIS 7/6) and recent Bayesian modelling suggests a more probable age of MIS 7 (‘Aveley’ Interglacial) possibly transitioning into MIS 6 (Marshall et el. 2020). However, palynology suggests an early (Boreal) interglacial assemblage either associated with climate amelioration (MIS 8-7) or cooling (MIS 7-6) although the pollen assemblage suggested some reworking (Tizzard et al. 2014).

The last interglacial period (Ipswichian MIS 5e) is represented by the Eem Formation which are shallow marine shell bearing sands that formed during sea-level highstand (Stoker et al. 2011). However, there is potentially more variability in MIS 5e deposits in the East Anglian region as fine-grained silts and clays deposited in a freshwater lake brackish estuarine environment were investigated as part of the Great Yarmouth Seabed Prehistory project (Wessex Archaeology 2008b). OSL dating of the fine-grained deposits returned an age of 117 ± 11 ka suggesting formation during the Ipswichian which is corroborated by biostratigraphy as seeds of the brittle water-nymph (Najas Minor) were observed and this species is not recovered in deposits later than MIS 5e in Britain. The sequence documents a shift to brackish and shallow marine environments likely indicating continued sea-level rise at the start of the Ipswichian. This is an extremely rare palaeoenvironmental and sea-level record of the last interglacial period in Britain that can be considered alongside the wider northwest European record (Cohen et al. 2021) and incorporated into the outputs of the Rates of Interglacial Sea-Level Change and Responses (RISeR) Project focusing on the rates, magnitude and spatial patterns of sea-level change during the last interglacial period.

The Eem Formation is succeeded gradually in some places, and more sharply in others by Brown Bank Formation which has been mapped widely across the East Anglia NSPRMF study area. To the west, Brown Bank Formation comprises fluviatile silt and laminated clays that infill a series of palaeochannels (Limpenny et al. 2011). One of these channels lies within Area 240 and is infilled by a lower unit of silty clayey sand overlain by an upper unit of interbedded sand and clay suggesting an increasing marine influence and deepening of water (Tizzard et al. 2014). To the east, Brown Bank comprises silty clays interpreted to have been deposited in an outer estuarine to lagoonal environment during the Early Devensian (MIS 5d-MIS 5a) as sea levels fell, but before ice sheets extended south into the southern North Sea (Stoker et al. 2011).

The Brown Bank channels in the west show evidence of multiple phases of cut and fill, changes in sediment grain size suggesting variable energy regimes and gas blanking which may suggest the presence of organic matter. Microfaunal assemblages from these deposits suggest a cool, restricted shallow marine environment and OSL dating suggests deposition between 53.4 ± 5.4 ka to 30.4 ± 6.9 ka (MIS 3) which is supported by the arboreal pollen assemblage typical of a Devensian interstadial (Limpenny et al. 2011).

Investigations of the Brown Bank Formation to the west at the Norfolk Boreas and Norfolk Vanguard OWFs show there is a degree of lateral and temporal variability within the deposits likely reflecting fluctuations in sea levels during the Early Devensian (Wessex Archaeology 2019a; 2019b). The Brown Bank Formation in these OWFs infills a basin that shallows towards the east, and the lower boundary of the Brown Bank Formation as mapped from seismic data indicates there is a bank feature that trends NW-SE (Eaton et al. 2020). The faunal assemblage suggests a shallow marine restricted embayment/lagoon but there is evidence of marginal shallower brackish environments suggesting the extent of the embayment/lagoon varied depending on sea level history (Wessex Archaeology 2019a; 2019b). Changes in water level are also apparent in seismic data and a field of dunes interpreted to be subaqueous tidal bedforms have been identified within the Brown Bank Formation in seismic data (Wessex Archaeology 2018g; Eaton et al. 2020). Shallow gas is also observed but no peat or organic-rich clays have been recovered to date.

OSL dating of the Brown Bank Formation recovered from the Norfolk Vanguard and Norfolk Boreas OWF suggests deposition between 82.4 ± 8.5 ka and 57.6 ± 5.9 ka (MIS 5b to MIS 3) which is broadly comparable to the dates obtained by Wessex Archaeology (2008b) and Tizzard et al. (2014; 2015). Collectively, the results suggest the Early Devensian North Sea lagoon/embayment persisted through MIS 5d to MIS 3 with a later phase of channelling initiated as the basin infilled and water depths shallowed, in combination with a fall in sea level at the end of MIS 3.

The resolution of seismic data, combined with detailed interpretation, paleoenvironmental analysis and dating was used to model palaeogeography at the stadial to interstadial timescale during the Early Devensian (Wessex Archaeology 2019a; 2019b). The results were important as they demonstrate that the palaeogeography of the North Sea during this time was variable and during periods of lower sea-level, parts of the landscape would have been habitable, potentially creating pathways into Britain after a potential period of hominin absence at the end of the last interglacial period. These types of reconstructions can be used to fill gaps or refine conceptual palaeogeographic reconstructions (Hijma et al. 2012; Eaton et al. 2020).

The Brown Bank Formation can be confused with the Brown Bank which is a geographic area of seabed in the Dutch sector of the North Sea. The Brown Bank area is known to preserve a wealth of faunal and artefactual remains that have been recovered by chance (‘stray finds’) (Peeters and Amkreutz 2020). Archaeological prospecting of this area was undertaken and while no artefactual material was recovered from the Brown Bank area, a peat bed outcropping at seabed was identified which is the likely context for Mesolithic discoveries to date (Missiaen et al. 2021). This peat bed is directly adjacent to the Norfolk Vanguard and Norfolk Boreas OWFs which preserve an extensive late glacial to early Holocene (MIS2/1) palaeolandscape (Wessex Archaeology 2019a; 2019b).

Geophysical, palaeoenvironmental and chronological assessment of deposits and features overlying the Brown Bank Formation in the Norfolk Boreas and Norfolk Vanguard OWFs identified an extensive network of meandering river channels fringed by wetland and woodland areas. In the Norfolk Boreas OWF, the sediment represent deposition in an active river environment during the Late Devensian (12,550-12,080 cal. BP) followed by a phase of peat development that commenced at the start of the early Holocene (11,710-11,260 cal. BP) and continued for a period of up to ~700 years.

The Norfolk Boreas record documents up to ~3,000 years of environmental history and shows the landscape was initially open grassland with localised reed and fen wetlands. During the early Holocene, woodland returned dominated initially by pine and later by hazel with some oak and elm. Inundation of the landscape is marked by an increase in vegetation tolerant to increased salinity marking a shift to saltmarsh and mudflat environments with final inundation occurring at ~9,700 cal. BP. This riverine/wetland landscape continued into the Norfolk Vanguard OWF. Radiocarbon dating suggests two possible phases of peat development: the first at 13,790-13,550 cal. BP and the second between 10,420-10,190 cal. BP and 10,170-9,740 cal. BP.

Collectively, over 85 km² of peat or organic deposits have been mapped across the Norfolk Boreas and Norfolk Vanguard OWFs providing a significant paleoenvironmental archive much larger than any previously studied in the wider North Sea and given the excellent preservation of palaeochannels that formed during the Late Pleistocene to early Holocene, there is very high potential for this submerged landscape to contain archaeological material.

Early Holocene channel systems have also been identified within the submerged PalaeoYare where they incise into the Pleistocene deposits (Tizzard et al. 2015). The early Holocene channel runs broadly north to south and can be traced as far south as Felixstowe. Sediments infilling the early Holocene channel comprise a transgressive sequence of intertidal mudflat/saltmarsh deposits overlain by shallow marine sands. Radiocarbon dating of channel infill indicate the deposition occurred between 12,620-12,100 cal. BP and 8,260-7,920 cal. BP under the influence of rising sea levels (Limpenny et al. 2011). The paleogeographic and palaeoenvironmental assessment of the early Holocene PalaeoYare suggests it would have been an attractive environment for Mesolithic human activity.

In addition to these studies focussed on local Pleistocene and Holocene landscapes, recent investigations using multi-proxy datasets, including palaeoenvironmental evidence, have linked catastrophic flooding of terrestrial landscapes in the norther part of the East Anglia NSPRMF study area to a tsunami event (Storegga) associated with series of underwater landslides in the northern North Sea, which is dated to 8,150 cal. BP (Gaffney et al. 2020; Walker et al. 2020).

Palaeoenvironmental records

Palaeoenvironmental datasets from the East Anglia obtained from direct sampling of Quaternary sediments are summarised in Table 9 .

Table 9 Quaternary palaeoenvironmental studies of vibrocore data carried out in the East Anglia region

Key submerged terrestrial Quaternary paleoenvironmental records from the East Anglia region are from the PalaeoYare, most notably within aggregate licence areas 254 and 240 (Wessex Archaeology 2008b, Tizzard 2015).

Preservation of paleoenvironmental evidence was poor from samples taken from the lower parts of the Pleistocene stratigraphy from Areas 254 and 240, including from Unit 3b, which has produced Middle Palaeolithic archaeology. However, palaeoenvironmental data has been key to reconstructing Late Pleistocene and early Holocene landscapes and environments. These record early Devenisan (MIS 5d-5a) sediments reflecting brackish tidal creek/estuarine environments, mid-Devensian (MIS 3) fluvial deposits and early Holocene units laid down in conditions within an outer-estuary, prior to marine inundation.

Pleistocene and Holocene environmental and palaeogeographic reconstructions for the East Anglia region have been further enhanced by recent studies carried out as part of the Norfolk Vanguard and Norfolk Boreas OFW projects (Wessex Archaeology 2019a, 2019b).

Faunal assemblages

Investigation of historic collections of terrestrial Qauternary vertebrate remains has identified material recovered by trawlers operating out of the port of Lowestoft that collected material from East Anglia region, including material which is provenanced to the north Norfolk coast (Bynoe 2014; Bynoe et al. 2016). Although biostratigraphically diagnostic pieces are dominated by post-Anglian (<MIS 12; <424 kya) Pleistocene species, these collections include a significant proportion of pre-Anglian mammals (e.g. southern mammoth). The number of pre-Anglian examples is particularly high for material from off the north Norfolk coast and east of  Great Yarmouth and, most notably in the collection of the Reverend James Layton, which can be predominantly provenanced to the ‘Oyster Bed’, located off Happisburgh (Layton 1827; Bynoe 2014, Bynoe et al. 2016). This high proportion of pre-Anglian material is indicative of an association with submerged deposits of the Cromer Forest Bed Formation (CF-bF).

In contrast to the material from off the north Norfolk coast, that recovered further south in the East Anglia region (from areas off Lowestoft and Southwold) (Bynoe et al. 2021) are dominated by post-Anglian species, including woolly mammoth and woolly rhino (Bynoe 2014, Bynoe et al. 2016).

New discoveries of terrestrial vertebrate fauna have also been made over recent years from the East Anglia region, most notably from marine aggregate licence Area 240 (Tizzard et al. 2015) (Figure 4). These include species diagnostic of multiple periods of the Pleistocene and Holocene. Approximately 130 individual pieces of fauna were identified during the initial 2007/2008 Area 240 discoveries (J. Glimmerveen in Tizzard et al. 2015), five of which produced radiocarbon dates of between 42,000 and 32,000 BP (MIS 3). After these initial discoveries, further pieces of fauna were recovered during seabed sampling and monitoring of dredging operations (Tizzard et al. 2015), as well as from the wharf in Vlissingen, Holland by the Natural History Museum of Rotterdam (Strijdonk et al. 2011; 2012).

These combined assemblages include material in a variety of states of fossilisation and combine Early to early Middle Pleistocene species of moose, deer, horse and southern mammoth, with late Middle to Late Pleistocene species (including straight-tusked elephant, woolly mammoth, woolly rhinoceros, steppe bison, giant deer and horse), as well as examples of red deer and bovid, considered to be Holocene (Strijdonk et al. 2011; 2012, Tizzard et al. 2015). This indicates that multiple stratigraphic units within Area 240 are fossiliferous, although the specific stratigraphic context of individual discoveries is unknown.

Further terrestrial mammal bones have been recovered from Area 240 as part of the BMAPA protocol and Operational Sampling events associated with aggregate extraction in the PalaeoYare catchment (Figure 4). The mammalian assemblage is dominated by woolly mammoth teeth and fragments of bone with rarer occurrences of aurochs, horse, antler from either red deer or reindeer, and rhinos scapula bone fragments. Chronological diagnostic finds are all indicative of late Middle to Late Pleistocene dates. Pleistocene material has also been recovered from other aggregate licence zones in PalaeoYare catchment, including Areas 212, 228, 251, 296, 319, 360 and 513/1.

Archaeological assemblages

Prehistoric archaeology recovered from the East Anglia region can be divided temporally between those of Palaeolithic (principally Lower/Middle Palaeolithic) and likely Mesolithic dates. Dating is principally based on typo-technological characteristic of artefacts; however, information on likely context for Palaeolithic material from the PalaeoYare catchment provides age estimates for these associated sediments.

Palaeolithic

The first Palaeolithic artefacts from Licence Area 240 were discovered were in 2007/2008 in stockpiles of gravel at SBV Flushing Wharf (Firth 2011, Tizzard, et al 2014). The finds were identified from stockpiles and reject piles between 7 December 2007 and 18 March 2008, in aggregate that had been dredged from Licence Area 240. The fresh condition of some of the artefacts indicated that they came from relatively undisturbed deposits. Comparison of the dates when material was recovered with the movements of the dredgers supplying the wharf revealed that the finds had been dredged from a small area within Licence Area 240. In order to prevent any damage to remains within the area, the marine aggregate company (HAML) voluntarily implemented an Archaeological Exclusion Zone (AEZ) covering this area.

Since 2011 aggregate dredging in licence areas in the PalaeoYare catchment have been subject to archaeological monitoring through Operational Sampling events conducted at aggregate wharves. These Operational Sampling events have identified further artefacts and palaeontological finds attributable to Area 240, as well as pieces from adjacent licence areas.

The techno-typological characteristics of the Palaeolithic artefacts from Area 240 are indicative of a Lower and/or Middle Palaeolithic age. Patterning in typo-technologically distinct artefact groups and the physical condition of these artefacts may indicate that two artefact assemblages, potentially reflecting multiple periods of Palaeolithic activity, are present – a handaxe-dominated one which is generally fresh, and a second Levallois-dominated one which exhibits some post-depositional modifications.

Two other notable Palaeolithic finds from the PalaeoYare catchment comprise Middle Palaeolithic Levallois flakes recovered north of Area 240 in Licence Area 212, one of which is in relatively fresh condition, whilst the other is abraded. These may originate from sediments that are broadly equivalent with Unit 3b in Area 240. Two very abraded, likely Lower/Middle Palaeolithic flakes have been identified from Licence Area 228, which is situated immediately south-east of Area 240.

Additional potentially Palaeolithic material has been recovered from licence areas 319 and 251 in the PalaeoYare catchment (see Figure 4). These comprise a stained and edge-damaged flake and a fresh flake with scraper retouch; the latter may not be Palaeolithic.

Significant numbers of Palaeolithic artefacts have also been identified amongst dredged aggregate from the East Anglia area which provided aggregate for the Bacton to Walcott Coastal Beach Nourishment Project. Marine licence areas located off the East Anglian coast were dredged, including licence areas 212, 228, 254, 494, 511, and 512 (Figure 4). Overall, approximately 1.5 million cubic metres of sediment was dredged and deposited on the beach in front of the Bacton Gas Terminal and the villages of Bacton and Walcott, with the aim of protecting these sites from erosion and flooding.

The work was undertaken separately to the PalaeoYare Operational Sampling. Similar Operational Sampling for archaeology was not possible for this project as aggregate was deposited directly on the beach. Instead, eight archaeological walkover surveys were undertaken following the deposition of aggregate on the beach. Only 12 finds were recovered from the walkover survey, none of which were prehistoric artefacts. Despite this, there is a wealth of archaeological material being recovered from the beach by local collectors indicating the archaeological material is there, but the success of a walkover survey is variable and is significantly influenced by local sediment transport which can bury or uncover archaeological material over timescales of a day. Marine archaeological guidance for beach replenishment/nourishment and contract fill projects is forthcoming (Wessex Archaeology 2022).

The dredging for the project avoided Licence Area 240, and therefore, the likely impact on sediments of known Palaeolithic archaeological potential was expected to be low. However, by March 2020, members of the public walking on the beach had discovered and reported between 750 and 1000 Palaeolithic artefacts, as well as 50 to 100 palaeontological finds. Review of the locations of the discoveries on the beach along with the dredging trackplots suggests that this archaeology originates from deposits dredged from either Licence Area 228 or 511 (Figure 4). This suggests the archaeological resource is more widespread across the East Anglia region and not focussed solely within Area 240.

Mesolithic

A total of four Mesolithic artefacts have been identified from the East Anglia region since 2009. As with the Palaeolithic artefacts, these have all been identified through reporting through the BMAPA protocol and Operational Sampling carried out as part of monitoring of aggregate extraction in aggregate licence areas located in the PalaeoYare catchment (Wessex Archaeology 2015c).

A bipolar blade core from Area 240 has been identified as later Upper Palaeolithic or of Mesolithic date, however, most potential Mesolithic finds are from areas located east of those where Palaeolithic material has been recovered.