Prior to the formation of the present-day North Sea during the mid-Holocene, North-Western Europe was connected through the Doggerland landmass. While it has been known for the past century that Doggerland was forested, it has not been clear when the onset of forestation occurred or whether the environment was more habitable for humans than surrounding European areas. In this study, we reconstruct the paleoecology of a river system, the Southern River, from the late Late Pleistocene to the late Holocene using sedimentary ancient DNA (sedaDNA) from 252 sediment samples from 41 cores spanning the length of the river system and headwater area. We identify secure and insecure sedaDNA signals by integrating sedimentological and sedaDNA data into a taphonomic model. Secure sedaDNA signals are found in silty and fine sand deposits where 95 to 98% originates from local deposition, but coarse sands and gravels are insecure with 60 to 70% of the sedaDNA associated with mixed ecosystem signals from reworked and influxed sediments. Secure sediments reveal the presence of several temperate tree genera such as Quercus, Ulmus, and Corylus over 16,000 y ago in the Late Pleniglacial, and thermal indicator genus Tilia several thousand years earlier than has been recorded for surrounding European areas. In this area, we also detect an anomalous signal of the genus Pterocarya, considered extinct in the region since the Hoxnian Stage (~400 ka). These observations are consistent with colonization from nearby northern glacial refugia, suggesting a favorable environment in which the cultural Mesolithic could develop.

Abstract The disappearance of Doggerland beneath the waves of the southern North Sea was the most notable landscape change to affect northwest Europe in the early Holocene. This submerged palaeolandscape has captured the imaginations of archaeologists and the public for over a century, but it is only in recent decades that our knowledge of it has begun to come into focus. Although often presumed as significant culturally, the area of Doggerland remains something of a geographical gap within our knowledge of Mesolithic northwest Europe. In part this reflects the fact that the archaeology of this area is largely restricted to finds made by chance discovery and sites located just off the current shore. Nevertheless, we are rapidly approaching a point where the targeted prospection of deeper waters may be possible. This chapter reviews our current knowledge regarding Mesolithic Doggerland, how it changed over time, and how these changes may have affected both the people who lived there and on the lands it once connected.

Development of the continental shelf has accelerated significantly as nations around the world seek to harness offshore renewable energy. Many areas marked for development align with submerged palaeolandscapes. Poorly understood and difficult to protect, these vulnerable, prehistoric landscapes provide specific challenges for heritage management. Indeed, there now appears to be a schism between what underwater cultural heritage policy intends and what it is achieving in practice. Shortcomings in international and national legislature ensures that large parts of the continental shelf, including areas under development, may have little or no legal protection. Increasingly impacted by extensive development, these unique cultural landscapes are ever more at risk. However, heritage challenges posed by such development also create opportunities. An immense amount of data is being generated by development, and there is an opportunity to establish broader cooperative relationships involving industrial stakeholders, national curators, government bodies, and heritage professionals. As a matter of urgency, the archaeological community must better engage with the offshore sector and development process. If achieved, we may revolutionise our knowledge of submerged prehistoric settlement and land use. Otherwise, our capacity to reconstruct prehistoric settlement patterns, learn from past climate change, or simply manage what are among the best-preserved postglacial landscapes globally may be irreparably undermined.

This paper presents the results of a pilot landscape-scale seismic survey undertaken in Apalachee Bay, Florida, across a submerged landscape that contains dozens of Pre-Contact sites. In addition to the goals of improving the geophysical and remote sensing ground model for this submerged landscape, the survey also sought to undertake the first independent scientific test of the contentious 'HALD' methodology, an acoustic resonance method that it is claimed to identify knapped lithic artefacts at and/or below the seabed through the identification of distinct 'haystack' responses. The results of this work indicate that the HALD method, as currently described, produces results that could not be scientifically replicated in this survey. We conclude that any HALD 'haystack' signal should therefore not be considered as an example of detection of human-modified lithic material but rather as a geophysical anomaly that requires additional constraints before it can be used to reliably identify human-modified lithic materials. Thus, although the authors note that laboratory studies have successfully produced an acoustic signal in human-modified lithics, the field-based methods remain yet to be reliably determined. In addition to these results, the landscape mapping survey also recorded valuable information on buried and previously unrecorded landscape features that have archaeological significance and that may guide future site prospection. We therefore conclude that despite the results of the HALD test, the well-preserved submerged landscape of Apalachee Bay region provides a highly useful testing ground for methods that can be deployed elsewhere globally.

Abstract Prior to the formation of the North Sea during the mid-Holocene, North-Western Europe was connected through the Doggerland landmass. Whilst it has been known for the past century that forests grew in Doggerland, it has not been clear how this environment compares to the surrounding European areas. Here, we reconstruct the palaeoecology of a river system from the Late Pleistocene to the late Holocene using sedimentary ancient DNA (sedaDNA) from 252 sediment samples from 36 cores spanning the length of the river system and headwater area. We determined that in low kinetic energy environments 95-98% of sedaDNA originates from local deposition and 2-5% is associated with influxed sediments, enabling the identification of secure deposits. High energy environments are insecure with 15-70% of sedaDNA associated with reworked and influxed sediment. Secure sediments reveal the presence of several tree species such as Alnus, Quercus, Ulmus and Corylus over 16000 years ago, and thermal indicator tree species like Tilia several thousand years earlier than has been recorded for surrounding European areas. In this area we also detect the presence of Pterocarya, previously unobserved since the Hoxnian. These observations are consistent with colonization from glacial refugia closer than the classic southern Europe refugia.

New high-resolution seismic data (Sparker) and very-high-resolution parametric echosounder (PES) data acquired in an area of the southern North Sea (the Flemish Bight) reveal its Quaternary seismic stratigraphy in unprecedented detail. The identified seismo-stratigraphic units and geomorphological features have been examined with the view to better understand the Quaternary evolution of the southern North Sea. Seven acoustic units were recognised, including Lower Pleistocene deltaic sediments, Eemian to lower Weichselian shallow marine to coastal (lagoonal) clay-silt-sands, and Holocene coastal peat layers overlain by intertidal and marine sediments. Four erosional events were identified, two of which can be traced as regionally occurring surfaces, and two occurring as localised incisions. Mapping of geomorphological features revealed potential Elsterian moraines in the UK sector, an Elsterian ice-pushed ridge in the Dutch sector and possible permafrost-related structures (probably dating to MIS3). Seven newly dated peat samples, acquired near a tidal sand ridge known as the Brown Bank from depths between 31 m and 34 m below sea level and dating to between 9.5 and 10.9 cal ka BP, indicate that this area was terrestrial during the early Holocene. The results form the basis to further improve the regional Quaternary stratigraphic framework of the area, to better understand the region’s (de)glacial history, to enhance sea-level reconstructions and to examine the area’s geographical importance for human occupation during Prehistory.

This paper describes some results of the research undertaken over the Brown Bank area during recent (2018/ 2019) geoarchaeological surveys in the North Sea which included seismic imaging, shallow (vibro)coring and dredging. It examines the benefits of simultaneous high-resolution (0.5 ? 1 m) and ultra-high-resolution (10?20 cm) seismic survey techniques and a staged approach to resolving the submerged Holocene landscape in the highest possible detail for the purpose of targeted prospecting for archaeological material from the Mesolithic landscape of Doggerland. The materials recovered from such surveys offer significantly greater information due to an enhanced understanding of the context in which they were recovered. The importance of this information cannot be understated archaeologically, as few locations on land provide the opportunity to recover archaeological finds in situ within preserved landscapes. Moreover, it allows offshore areas of potential human activity to be prospected with some certainty of success.

Around 8150 BP, the Storegga tsunami struck North-west Europe. The size of this wave has led many to assume that it had a devastating impact upon contemporaneous Mesolithic communities, including the final inundation of Doggerland, the now submerged Mesolithic North Sea landscape. Here, the authors present the first evidence of the tsunami from the southern North Sea, and suggest that traditional notions of a catastrophically destructive event may need rethinking. In providing a more nuanced interpretation by incorporating the role of local topographic variation within the study of the Storegga event, we are better placed to understand the impact of such dramatic occurrences and their larger significance in settlement studies.

During the late glacial and early Holocene, vast areas of dry land stretched from the British Isles to continental Europe over what is now the southern part of the North Sea. Whilst it is known that this landscape was inhabited, little is known about the cultures that lived there and the surrounding environment. This study focuses on the Brown Bank area, between the UK and Dutch coasts, with its significant 25 km long and 10-15 m high ridge on the seabed which has provided many Mesolithic ex-situ finds. However, all of these finds have been recovered serendipitously due to commercial fishing and dredging, and thus the landscape and sedimentary context of these archaeological finds is unclear. The goal of this study is to map the terrestrial features in the Brown Bank area and reconstruct the palaeolandscape and its inundation to determine the potential locations from which this archaeological material derives, and potentially locate Mesolithic settlement sites. The project uses high-resolution parametric echosounder surveys in a dense survey network to record the area and facilitate later targeted dredging and vibro-core sampling. The seismic surveys revealed a pre-marine inundation landscape with fluvial channels eroded into post glacial sediments. A peat layer was located on the top of the banks of the channels where it continues laterally hundreds of metres. Radiocarbon dating of the top part of the peat layer, just below the transgressive deposits gave ages around 10.2-9.9 cal ka BP. Palaeogeographic reconstructions based on the mapped terrestrial features and the available relative sea level change data suggest that the final inundation of the area happened c. 1000 years later. Where dredging was carried out in areas of interest, primarily where the early Holocene surface outcropped onto the seabed, a large number of blocks of peat with pieces of wood and other macrofossils were recovered, suggesting a good potential for preservation of possible archaeological material and possible locations of origin for the serendipitous finds made by fishermen. We conclude that this study provides new insights into the palaeogeography and the timing of the inundation of the Brown Bank area and gives the landscape context to the potential Mesolithic habitation of this part of the southern North Sea.

Doggerland was a landmass occupying an area currently covered by the North Sea until marine inundation took place during the mid-Holocene, ultimately separating the British landmass from the rest of Europe. The Storegga Event, which triggered a tsunami reflected in sediment deposits in the northern North Sea, northeast coastlines of the British Isles and across the North Atlantic, was a major event during this transgressive phase. The spatial extent of the Storegga tsunami however remains unconfirmed as, to date, no direct evidence for the event has been recovered from the southern North Sea. We present evidence of a tsunami deposit in the southern North Sea at the head of a palaeo-river system that has been identified using seismic survey. The evidence, based on lithostratigraphy, geochemical signatures, macro and microfossils and sedimentary ancient DNA (sedaDNA), supported by optical stimulated luminescence (OSL) and radiocarbon dating, suggests that these deposits were a result of the tsunami. Seismic identification of this stratum and analysis of adjacent cores showed diminished traces of the tsunami which was largely removed by subsequent erosional processes. Our results confirm previous modelling of the impact of the tsunami within this area of the southern North Sea, and also indicate that these effects were temporary, localized, and mitigated by the dense woodland and topography of the area. We conclude that clear physical remnants of the wave in these areas are likely to be restricted to now buried, palaeo-inland basins and incised river valley systems.

1 Flanders Marine Institute (VLIZ), InnovOcean site, Wandelaarkaai 7, 8400 Oostende, Belgium E-mail: tine.missiaen@vliz.be 2 Universiteit Gent: Vakgroep Geologie (UGent), Krijgslaan 281, 9000 Gent, Belgium 3 University of Bradford, Richmond Road Bradford BD7 1DP, United Kingdom 4 TNO (Geologische Dienst Nederland), Princetonlaan 6 3584 CB Utrecht, The Netherlands 5 Deltares: Unit Zeeen Kustsystemen (DELTARES-ZKS), PO Box 177, 2600 MH Delft, The Netherlands 6 Rijksuniversiteit Groningen, PO Box 72 9700 AB Groningen, The Netherlands