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This paper provides the most-accurate sea-level index points (SLIPs) for the Rhine-Meuse Delta (RMD), The Netherlands, identified amidst a wealth of data accumulated in sixty years of research. Following documented protocols, 106 selected radiocarbon dates from peat beds from transgressed valley floor, upper estuarine and back-barrier lagoonal settings were first listed individually, then screened in ensemble on quantified age-depth position and inshore palaeotidal setting. The database contains 50 SLIPs and 56 upper limiting data points spanning a depth range of −34 to −1.5 m. The dates in the database originate from dedicated sea-level research, which kept surface elevation and sampling depth uncertainty small, and sampling of basal-peat beds was favoured, keeping compaction uncertainties small too. The SLIPs cover an age-range of 8.8–3.0 ka BP and are available from Greater Rotterdam and its near offshore. For upper limiting data points, the coverage extends offshore, tracing the Rhine palaeovalley, and reaches back to 11.5 ka BP. The age-depth data density and spatial concentration of subsets of dates allow to perform Bayesian radiocarbon calibration and to reduce temporal uncertainty by 25% for the average sample (1σ age uncertainty ≈ 75 cal. yr), when depth position and rates of relative sea-level rise (RSLR) are used to assign sequence order. Between 8.0–4.5 ka BP, rates of RSLR gradually decreased from 9 to 1 mm/yr. In the millennium before, rates of RSLR were much higher, on average 10 mm/yr, and marked by a sea-level jump between 8.45–8.2 ka BP. A two-phased nature of this jump starts to be resolved, with local magnitudes of 1.7 ± 0.6 m (1σ, first phase) and 0.2 ± 0.2 m (second phase), corresponding to globally-averaged jumps of 2.5 m ± 0.9 m for the first and 0.3 ± 0.3 m for the second phase. For the pre-9 ka BP period, only offshore upper limiting data points are currently available. Until new offshore data are gathered, trends of RSLR before 9 ka BP can only be estimated, fed with global insights in post-glacial eustasy, regional estimates regarding rates of glacio-isostatic adjustments and tectonic subsidence, and sedimentary geological interpretations of scattered basal-peat presence.

Holocene fluvial and estuarine systems are commonly assumed to be entirely alluviated, which means that channels freely move in erodible substrates. This implies that the shape and tidal bar patterns are self-formed. Data analysis for estuaries and deltas worldwide, however, proves presence geological depth constraints in many, if not most systems. This potentially constrains estuary channel dimensions and planform shape. In this study we compare detailed historical bathymetry maps of the last two centuries and depths of resistant Pleistocene clays and tills in the Eems-Dollard estuary, located on the Dutch-German border. Based on this new historical and geological data we show how resistant layers forced bar patterns and channel dimensions in an estuary that was hitherto considered autogenically-formed. Resistant layers limit channel depth and consequently cause widening and mid-channel bar formation, increasing channel curvature over at least one bar length in both seaward and landward direction (Figure 1). Furthermore, channel confluences preferentially form where resistant layers are absent. These combined effects determine the position of confluences and bars on the scale of the entire estuary; they are tuned to the presence of the resistant layers. Our results challenge the view that bar-filled estuaries are predominantly self-formed. They show that apparently local obstacles have estuary-wide implications: they can, for example, force bar formation and increased channel curvature that may favor the stability a two channel system. Future sea-level rise may cause tidal prisms and consequently the channel volumes to increase. As a result, the resistant layers are expected to be more exposed on the bases and edges of estuary channels, leading to potentially unexpected channel behavior when their effects are not taken into account. This strongly highlights the need to incorporate inherited resistant layers into morphological models.

The long‐term morphodynamic evolution of estuaries depends on a combination of antecedent topography and boundary conditions, including fluvial input, sea‐level change and regional‐landscape interactions. Identifying effects of such boundary conditions on estuary evolution is important to anticipate future changes in specific boundary conditions and for hindcasting with numerical and physical models. A comprehensive synthesis of the evolution of the former Old Rhine estuary is presented here, together with its boundary conditions over its full lifespan from 6,500 to 1,000 cal. yr bp. This system formed during a period of sea‐level high stand, during which the estuary served as the main River Rhine outlet. The estuary went through three stages of evolution: a maturation phase in a wide infilling back‐barrier basin, a stable mature phase and an abandoning phase, both in a laterally confined setting. The Old Rhine River formed by a river avulsion around 6,500 cal. yr bp that connected to a tidal channel within a large back‐barrier basin. Decelerating sea‐level rise caused the back‐barrier basin to silt up around 5,700 cal. yr bp, resulting in shoreline progradation by beach‐barrier formation until ∼2,000 cal. yr bp. Beach‐barrier formation along the coast and natural levee formation along the river triggered peat formation in the coastal plain, laterally constraining the estuary and limiting overbank deposition, which caused most sediment to accumulate offshore. The abandoning phase started around 2,200 cal. yr bp when a series of upstream avulsions led to a substantial reduction in fluvial input. This induced a period of enhanced estuarine overbank clay deposition that continued into near‐complete silting up and estuary closure around 1200 ad. These findings exemplify how tidal systems, formed in wide coastal plains during sea‐level high stand, depend on antecedent conditions, and how they respond to connection and disconnection of a large river over long, millennial timescales.

In a geological GIS-data recombination project, a digital map was produced that holds information on the Netherlands’ former coastal and delta plain landscapes in the last 14,000 years: the Holocene and the very end of the Pleistocene. The end product polygon maps are accompanied by a set of palaeoDEMs indicating the ‘attention depth’ for buried land surfaces and aquatic deposits; both for four time slices. This paper provides conceptual background on legend and construction principles of the polygon maps and the palaeoDEMs (‘decisions during the making off’) and a basic overview of the map product (‘landscape structure’, ‘burial depth’, ‘preser¬vation’), visualised for the four time slices of RCE’s Archaeological Knowledge Kit. The text links the coastal plain buried landscape mapping for time slices T0, T1, T2 and T3, to the other Knowledge Kit activities described in this volume, notably that of the Archaeological Landscape map (for time slice T4 in the coastal plain part of The Netherlands, for time slice T0 to T4 in the Pleistocene uplands).

Chapter 7 in the 'SPLASHCOS Taphonomy book', on the landscape-archaeological inventory of the North Sea as a regional sea (covering British, Dutch, Belgian, German and Danish sectors of the southern and central North Sea). Abstract: This chapter gives a general overview of knowledge regarding the North Sea area in the context of Quaternary prehistory. The North Sea is one of the larger continental shelf seas in the world. Much of it was exposed and potentially habitable during periods of lower sea-level. It is one of the world’s better researched shelf, and the research history stared relatively early. The discovery of hydrocarbons in the mid-1960s triggered both commercial exploration and state-governed mapping. In later years, the search for sand and gravel reserves and large-scale windfarm development brought a second wave of research that continues to today. It is practically impossible to give an exhaustive review of the data, maps and publications that are available. Hence this chapter will only give a general overview based on recent geological-archaeological publications. It will focus on Quaternary palaeogeographical change since the first hominin occupation of the North Sea, outline the evidence for preservation of archaeological sites and landscapes and discuss taphonomic issues relating to preservation. Where preserved, surfaces of Lateglacial and Early Holocene landscapes are part of the upper few meters of the sea floor. Remnants of earlier inhabitable landscapes occur at a larger range of depths. To surveying the North Sea floor for preserved fossil landscapes and to forecasting the taphonomy as part of predictive mapping, geological mapping and palaeogeographical reconstruction are important prior steps. Knowledge on landscape preservation further helps to understand the taphonomy of encountered submerged archaeological sites. The key point to be made for the North Sea is that while there is confirmation that remnants of Pleistocene and Holocene landscapes and their associated archaeological record are preserved, the overall evidence base is complex, patchy and fragmented, reflecting a range of spatio-temporally variable formative and destructive processes. In most cases the existing types of data do not suffice for confident taphonomic assessments, despite their great density. For offshore areas, it is easier to predict what past depositional environments and hominin habitats once occurred, than to locally predict the state of preservation of archaeology today. Yet, that second step is important in seafloor heritage research and management decisions and designs of underwater surveying and excavation plans. The chapter therefore works towards identifying the taphonomic variables, in applications at at local, regional and superregional scale. This is done by providing an overview of geological history and a landform inventory for the North Sea, highlighting links with taphonomy through the text.

Databases of palaeoclimate data have driven many major developments in understanding the Earth system. The measurement and interpretation of palaeo sea-level and ice-sheet data that form such databases pose considerable challenges to the scientific communities that use them for further analyses. In this paper, we build on the experience of the PALSEA (PALeo constraints on SEA level rise) community, which is a working group inside the PAGES (Past Global Changes) project, to describe the challenges and best strategies that can be adopted to build a self-consistent and standardised database of geological and geochemical data related to palaeo sea levels and ice sheets. Our aim in this paper is to identify key points that need attention and subsequent funding when undertaking the task of database creation. We conclude that any sea-level or ice-sheet database must be divided into three instances: i) measurement; ii) interpretation; iii) database creation. Measurement should include postion, age, description of geological features, and quantification of uncertainties. All must be described as objectively as possible. Interpretation can be subjective, but it should always include uncertainties and include all the possible interpretations, without unjustified a priori exclusions. We propose that, in the creation of a database, an approach based on Accessibility, Transparency, Trust, Availability, Continued updating, Completeness and Communication of content (ATTAC3) must be adopted. Also, it is essential to consider the community structure that creates and benefits of a database. We conclude that funding sources should consider to address not only the creation of original data in specific research-question oriented projects, but also include the possibility to use part of the funding for IT-related and database creation tasks, which are essential to guarantee accessibility and maintenance of the collected data.

Postglacial sea-level rise at the start of the Holocene continued to drown continental shelves around the world. By the early–middle Holocene transition, deltas and other coastal systems had begun to stabilize their positions, which have since been maintained. The last major acceleration of sea-level rise occurred between 8.5 and 8.2 ka, due to the largest meltwater pulse from a single source area, released from the thawing Laurentian ice sheet in the Hudson Bay area. This event left a marked transgressive impact on river-mouth sedimentary sequences around the globe, exemplified in the Rhine Delta (North Sea, The Netherlands) from boreholes and underground exposures in the city of Rotterdam and its megaharbour. What ended as the 8.2 ka climatic event actually began as a freshwater release at ~8.45 ka: it should therefore be properly regarded as an 8.5–8.2 ka event. In contrast to the 8.2 ka climatic event, which was temporary, globally highly variable, and commonly insignificantly registered, and which only indirectly affected sedimentation, the sea-level imprint of the freshwater release was permanent, circumoceanic, and predictably spatially variable, and had direct impacts on sedimentation on both sides of the migrating coastline. Consequently, the water release left lithostratigraphic- and environmental-event boundaries in coastal sequences around the world, in the zone where Holocene accumulations are thickest and functional subdivision is architecturally most important. For these reasons, the sea-level signal of the 8.5–8.2 ka event should be considered as the beginning of a formalized Middle Holocene, and not the somewhat-later 8.2 ka cold spell maximum over Greenland, as is currently being proposed elsewhere. In that context, the transgressive contact found at the base of the Rhine Delta at Rotterdam is presented as a potential GSSP (8450 ± 44 cal BP).

Het is in de herfst van 2005. Een lief meisje, Marieke, rijdt op haar vouwfiets door Rotterdam. Bij het Centraal Station is het al tijden een grote bouwplaats. Onder de nieuwe hal komt een veel groter metrostation en ook onder de Statenweg in Blijdorp is een grote bouwput voor een nieuw station. Meestal fietst ze er snel langs, maar die dag ziet ze een glimp van een meer dan 10 m diep gat. Ze weet niets van geologie of sedimentologie, maar denkt toch aan ons, liefhebbers van de ondiepe ondergrond van West-Nederland. Zo begint het verhaal van onze mooiste ontsluiting: die van de basis van de delta in de Blijdorp-bouwput van de RandstadRail. We zouden de put bezoeken, de sedimenten aanraken en er zorgvuldig wat monsters in zakjes stoppen. De put hielp ons de transgressieve omslag in het Rijnmondgebied, van rivierdal naar estuarium, gedurende de eerste helft van het Holoceen in de vingers te krijgen. Ons onderzoek voegde ook een nieuw verhaal toe aan het boek over de versnelde wereldwijde zeespiegelstijging tussen 8,450 en 8,200 jaar geleden. Dit als gevolg van het leeglopen van het fameuze Lake Agassiz aan de overkant van de Atlantische Oceaan. Een vroeg-Holoceen Rotterdams Holland-Amerika lijntje dus.

In the Holocene Rhine-Meuse delta, the geography, architecture, and chronology of the channel belts and their flood basins is known in exceptional high detail. This is due to a long history of intensive geological, geomorphological, and archeological research by various universities and knowledge institutes and archaeological consultancy companies. A first reconstruction showing the build-up and palaeogeographical development of the delta in 500 year time-slices was published in 2001 by Berendsen and Stouthamer. The mapping turned out to be of great value for academic and applied studies in archaeology, hydrology, and sedimentary geology. Now, more than a decade later, knowledge of the evolving delta river network has majorly grown in both coverage and accuracy.

This poster presents paleogeographical scenario maps for the southwestern North Sea Basin, where onshore and offshore territories of Belgium, The Netherlands, France and England meet. Originally prepared and published as a backdrop for paleolithical geoarcheological research (Hijma et al. 2012; JQS), we are now expanding this with fieldwork in NW Belgium. NW Belgium is a key area to resolve current debates on the timing and rates of erosion and landscape change in this area over multiple glacial-interglacial cycles. With the Thames Estuary, it shares a history of drastic river valley network reconfigurations between successive glacials in the youngest 500,000 years. With the SW Netherlands it shares the sea level rise history in Eemian and Holocene. With NW France and SE England, it shares the river incision history that accelerates and changes in position with the opening of the Strait of Dover in the last 500,000 years. What are regionally separated issues in surrounding countries, comes together and superimposes in the Belgian Quaternary record. Our fieldwork aims at logging and sampling for a long-term landscape erosion studies, progressively over multiple glacial-interglacial cycles, and for generic regional quaternary geological mapping and dating.

In May 2009, Orson van de Plassche sadly passed away. In a paper of which parts, especially the discussion section, were written after his death, new data and a revision of an existing sea-level curve are presented for the Rotterdam area (Van de Plassche et al., 2010). This comment concerns two topics addressed in the discussion section: 1) connection of their revised Rotterdam relative sea-level curve for the period 7900-5300 cal yr BP (MSL-R2; Jelgersma, 1961; Van de Plassche, 1982; 1995; Berendsen et al., 2007; Van de Plassche et al., 2010) to the sea-level curve for the same area for the period 9000-7500 cal yr BP (MSL-R1; Hijma & Cohen, 2010); 2) The role of the river gradient on the calculation of the magnitude of a sea-level jump that occurred between 8450-8250 cal yr BP (Hijma & Cohen, 2010).

We present a detailed reconstruction of the palaeogeography of the Rhine valley (western Netherlands) during the Holocene transgression with systems tracts placed in a precise sea-level context. A high level of detail could be reached because of 1) favourable antecedent topography and subsidence setting; 2) long history of coring, mapping, dating, establishing facies models; 3) New 3D-techniques of dealing with the wealth of data and 4) key papers produced in recent years. The reconstruction permits comparison of actual versus conceptual boundaries of the lowstand, transgressive, and highstand systems tracts. It shows that the inland position of the highstand Rhine river-mouth on a wide, low-gradient continental shelf meant that base-level changes were the dominant control on sedimentation for a relatively short period of the last glacial cycle. Systems in such inland positions predominantly record changes in the balance between river discharge and sediment load and preserve excellent records of climatic changes or other catchment-induced forcing. We furthermore show that the Transgressive Systems Tract-part of the coastal prism formed in three stages: (1) The millennium before 8.45 ka BP, when the area was dominated by fluvial environments with extensive wetlands; (2) The millennium after 8.45 ka, characterized by strong erosion, increasing tidal amplitudes and bay-head delta development and (3) the period between 7.5-6.3 ka BP when the Rhine avulsed multiple times and the maximum flooding surface formed. The diachroneity of the transgressive surface is strongly suppressed because of a pulse of accelerated sea-level rise at 8.45 ka BP. That event not only had a strong effect on preservation, but has circum-oceanic stratigraphical relevance as it divides the early and middle Holocene parts of coastal successions worldwide. We propose that a marine deltaic sequence recording the 8.45-8.25 event could well host the Global Stratigraphical Section and Point for the Middle Holocene.

This study presents a detailed reconstruction of the palaeogeography of the Rhine valley (western Netherlands) during the Holocene transgression with systems tracts placed in a precise sea-level context. This approach permits comparison of actual versus conceptual boundaries of the lowstand, transgressive and highstand systems tracts. The inland position of the highstand Rhine river mouth on a wide, low-gradient continental shelf meant that base-level changes were the dominant control on sedimentation for a relatively short period of the last glacial cycle. Systems in such inland positions predominantly record changes in the balance between river discharge and sediment load, and preserve excellent records of climatic changes or other catchment-induced forcing. It is shown here that the transgressive systems tract-part of the coastal prism formed in three stages: (i) the millennium before 8·45 ka bp, when the area was dominated by fluvial environments with extensive wetlands; (ii) the millennium after 8·45 ka, characterized by strong erosion, increasing tidal amplitudes and bay-head delta development; and (iii) the period between 7·5 and 6·3 ka bp when the Rhine avulsed multiple times and the maximum flooding surface formed. The diachroneity of the transgressive surface is strongly suppressed because of a pulse of accelerated sea-level rise at 8·45 ka bp. That event not only had a strong effect on preservation, but has circum-oceanic stratigraphical relevance as it divides the early and middle Holocene parts of coastal successions worldwide. The palaeogeographical reconstruction offers a unique full spatial–temporal view on the coastal and fluvial dynamics of a major river mouth under brief rapid forced transgression. This reconstruction is of relevance for Holocene and ancient transgressive systems worldwide, and for next-century natural coasts that are predicted to experience a 1 m sea-level rise.