At the locality of Heidebos (Moervaart area, N Flanders, Belgium), a sedimentary core was taken in the Maldegem-Stekene coversand ridge and dated using optically stimulated luminescence (OSL). The study aimed at contributing to an improved understanding of the evolution of the physical landscape around archaeological settlements in this area. The core comprised a 7 m thick series of laminated and massive aeolian sands, in which several organic layers were intercalated. From this sequence, 11 samples were collected for quartz-based SAR-OSL dating; an internally consistent dataset was obtained. The ages of the lowermost 1 m of the sedimentary sequence (15.5±1.1 ka and 17.3±1.3 ka) imply that these sediments may represent the time-equivalent deposit of a deflation phase that occurred during the Late Pleniglacial and led to the formation of a widespread desert pavement, regionally known as the Beuningen Gravel Bed. However, a significant part of the sediments (at least 4 m) was deposited later, i.e. during the Allerød and/or the Late Dryas. As such, the results allow establishing the genesis of the coversand ridge at the Heidebos locality on the basis of direct age information. The relatively high sedimentation rate and the absence of extensive soil formation in the record reflect periods of pronounced aeolian activity and landscape instability during the Late Glacial, which provides part of the environmental framework for human occupation in the area.

The impact of oil and, in particular, gas fields discovered in the Dutch subsurface has been very significant. However, 50 years after the discovery of the giant Groningen gas field the Netherlands has become very mature for exploration of oil and gas, and the gas volume left to be discovered in conventional traps is insignificant compared to what has been found already. The total portfolio of conventional prospects held by the industry contains several 100s of billions of cubic metres (bcm), as reported by the Ministry of Economic Affairs, but many of these prospects are unattractive to drill because of their small size or other geologically unfavourable aspects. Hence, for planning purposes of future national gas production the risk should be taken into account that the size of the conventional portfolio is overestimated. The major E&P companies have reduced their exploration efforts and the number of wells drilled as well as the size and total volume of discovered gas reserves has seen a steady decline over the last 10 years. Some surprises may still be in store and can occasionally add a welcome addition of gas. But the follow-up potential of new play and trapping concepts has been disappointing for many years now, and it is concluded that this is unlikely to be different in the future. Remaining conventional discoveries will mainly be in small near-field targets that as a result of technological advances made in the last few decades can be drilled with high confidence, despite their small volumes.

This leaves the so-called unconventional gas (UG) resources for a real and significant increase in the exploration potential of the Netherlands. UG resources occur outside conventional structural or stratigraphic traps in tight (low permeability) rocks and are of regional or sub-regional extent, without well-defined hydrocarbon-water contacts. The potential for Basin Centred Gas, Shale Gas and Coal Bed Methane is reviewed. As, according to present-day technology, development of UG requires very dense drilling at low costs with well spacing of a few 100s of metres, only the onshore potential can be commercial, even in the longer term.

Recent geological uplift is a characteristic for all North American commercial UG developments. Uplift helps bringing the resources close to the surface and facilitates development of fractures, which are essential for achieving commercial flow rates. This significantly reduces the area where commercial UG resources may occur in the Netherlands. In addition, sweet spots, where commercial flow rates and ultimate recovery per well can be achieved, represent only a fraction of the total ‘play area’. The UG plays in the Dutch subsurface remain to be proven, and there is still a significant technical risk associated with these plays, on top of the commercial risk. Therefore, despite potentially enormous in-place gas volumes in these unconventional plays, recoverable volumes are much less. If UG resources can be proven and are commercially developable, their cumulative volume potential is estimated by us in the order of a few tens to one or two hundreds bcm of recoverable gas at best. Finally, as UG resources produce at very low rates and require large numbers of wells to develop, the environmental impact in a densely populated country like the Netherlands is enormous, and needs to be seriously considered, already in the exploration phase.

In a mature area like the Netherlands, industry focus should be on technology development to reduce risk, increase recovery, reduce cost and minimize surface impact. Cooperation between Operators to build multi-well campaigns is therefore strongly recommended to reduce mobilisation cost. In addition, government incentives should be targeted at the development phase, in order to increase economic attractiveness for difficult reservoirs, both conventional and unconventional. In this way State and industry will both be able to maximize their returns on the remaining potential for gas and oil in the next two to three decades.

This special issue focuses on the interactions between Quaternary Geology and Archaeology and results from the INQUA-NL Symposium: ‘Late Quaternary Climate Change: a Human Perspective’ held on April 14th 2009, KNAW Trippenhuis, Amsterdam. The symposium was attended by over 125 scientists and students with interest in the fields of Quaternary Geology and Archaeology. The symposium was organized for the INQUA Netherlands commission (INQUA-NL) by Wim Hoek, Faculty of Geosciences, Utrecht University (UU), Henry Hooghiemstra, Faculty of Science, University of Amsterdam (UvA), and Jos Deeben, National Service for Cultural Heritage (RCE). The INQUA Netherlands commission (INQUA-NL) is the Netherlands' national representation in INQUA, the International Union for Quaternary Research (see further www.geo.uu.nl/inqua-nl).

The Netherlands is a country made by humans, but before the large-scale impact of humans that formed the typical Dutch landscape, people inhabited our area and needed to be able to deal with natural disasters like climate change, river floods or sea-level change. In the field of archaeology, there is increasingly more space to include the environmental changes that partly determined the behaviour of prehistoric communities. The interactions between quaternary geology and archaeology are not only restricted to provide stratigraphical information during archaeological prospection or on exposures during excavations. Quaternary geology is increasingly applied to gain insight in the landscape development and environmental setting where people have lived in the past. Above this, predictive models can be improved by the interaction of archaeological and geological/palaeogeographical research (see also Deeben et al., 2010).

We present a revised relative mean sea-level (MSL) curve for the Rhine-Meuse delta, western Netherlands, for the period 7900-5300 cal yr BP. The revision is based on a series of new and previously unpublished local groundwater-level index data from buried Late Glacial aeolian dunes in the lower Rhine-Meuse delta, and reinterpretation of existing data.

The new index data consist of (AMS and conventional) radiocarbon dates of samples, collected from the base of peat formed on dune slopes, near Vlaardingen (21 index points), Hillegersberg (one index point), and Hardinxveld-Giessendam (10 index points). The Vlaardingen data represent the coast-nearest Rhine-Meuse delta local water-level record, which therefore is highly indicative for sea-level change. Pollen and macrofossil analysis, and dating of paired samples was carried out to assess the reliability of the groundwater-level index data.

The revision of the MSL curve involves: (1) a significant (0 to >1 m) upward adjustment for the period 7900-7300 cal yr BP; (2) a downward adjustment of <0.25 m for the period 6650-5300 cal yr BP. The new data indirectly support the reliability of the part of the curve for the period 7300-6650 cal yr BP. A longitudinally fairly uniform river gradient of 2.5-3.0 cm/km in the lower Rhine-Meuse delta during the period 6650-5600 cal yr BP can be inferred from the data sets. A significant river gradient extended further towards the coastline than previously thought and it may be that also the revised MSL curve reflects river-gradient effects. An increased floodbasin effect (stronger intra-coastal tidal damping) seems to have developed in the lower Rhine-Meuse delta in de period 7500-6600 cal yr BP, and was probably a complex response to a major avulsion of the Rhine.

Botanical microfossils, macroremains and oribatid mites of a Weichselian interstadial deposit in the central Netherlands point to a temporary, sub-arctic wetland in a treeless landscape. Radiocarbon dates and OSL dates show an age between ca. 54.6 and 46.6 ka cal BP. The vegetation succession, starting as a peat-forming wetland that developed into a lake, might well be linked with a Dansgaard-Oeschger climatic cycle. We suggest that during the rapid warming at the start of a D-O cycle, relatively low areas in the landscape became wetlands where peat was formed. During the more gradual temperature decline that followed, evaporation diminished; the wetlands became inundated and lake sediments were formed. During subsequent sub-arctic conditions the interstadial deposits were covered with wind-blown sand. Apart from changes in effective precipitation also the climate-related presence and absence of permafrost conditions may have played a role in the formation of the observed sedimentological sequence from sand to peat, through lacustrine sediment, with coversand on top. The Wageningen sequence may correspond with D-O event 12, 13 or 14. Some hitherto not recorded microfossils were described and illustrated.

Recent studies have demonstrated the complex depositional history of the Vijlen Member (Gulpen Formation) in the Maastricht-Aachen-Liège area, on which synsedimentary tectonics had a profound impact, in conjunction with regressive and transgressive episodes, the oldest portion of this member being preserved only locally, within channel-like structures. Our reinterpretation of the Vijlen Member, here presented, is at variance with current belemnite stratigraphy. To account for incongruities, reworking of belemnites is here proposed as a typical feature during Vijlen Member deposition. A renewed study of belemnites on the basis of these new data suggests that intervals 4–6 of the Vijlen Member are of late Maastrichtian age. With respect to the mean values of populations of Belemnitella junior Nowak and Belemnitella Iwowensis Naidin, Vijlen Member intervals 4–5 are coeval with the Spyridoceramus tegulatus/Belemnitella junior Zone (sensu germanico), whereas at least the upper portion of interval 6 is correlatable with the basal Tenuipteria argentea/Belemnitella junior Zone (sensu germanico). Although reworking of belemnites appears to have been a common feature, this cannot be properly substantiated without additional geochemical analyses of individual guards. For this reason, we refrain from proposing a biostratigraphic zonation of the Vijlen Member based on belemnites. Alternatively, scaphitid ammonites might be used to subdivide this member, because species such as Acanthoscaphites (Acanthoscaphites) tridens (Kner), A. (Euroscaphites) varians blaszkiewiczi Jagt, Kennedy & Machalski, Hoploscaphites constrictus (J. Sowerby), H. tenuistriatus (Kner) and Hoploscaphites sp. have been recorded. The last-named taxon represents an interspecies hybrid between the North American Jeletzkytes dorfi Landman & Waage and an unidentified subspecies of the endemic European lineage of H. constrictus, allowing correlation of the lower portion of Vijlen Member interval 6 with the Hoploscaphites birkelundae Zone of the United States Western Interior.

Facies belts exhibit a back-stepping trend towards the London Brabant/ Rhenish Massif through the Early Cretaceous. The overall eustatic sea-level rise was punctuated by short-term tectonic events identified either as localised or North Sea wide in extent. The biostratigraphically constrained sequences have, for the first time, allowed a detailed calibration of tectonic and eustatic events on a North Sea scale. The most extensive database available to any North Sea Cretaceous study was available to the authors together with a comprehensive suite of new high-resolution biostratigraphy and sedimentology. This has allowed unique insights into provenance, depositional environment, extent of sequence stratigraphical events and the degree to which unconformities have been tectonically accentuated.

This paper reports the discovery of an in-situ striated, far-travelled, oversized clast in the Ardleigh Gravels of the Kesgrave Sands and Gravels of the River Thames at Ardleigh, east of Colchester in Essex, eastern England. The morphology, petrography and geochemistry of the clast, and the sedimentology of the host deposit are described. The striations are interpreted, on the basis of their sub-parallelism and the shape and sub-roundedness of the clast, as glacial and the clast is provenanced to Ordovician rocks of the Llŷn and Snowdonia regions of North Wales. On the basis of clast frequency within the Colchester Formation gravels of the Kesgrave Sands and Gravels it is inferred that glaciers reached the Cotswold region of the Thames catchment. Floe-ice transport during spring flood is invoked for movement from the glaciated region to eastern England. The paper discusses the possible age of the glaciation and recognises that it is difficult to be more precise than a cold stage in the early Middle Pleistocene (MIS 18, 16 or 14). Attention is drawn to the possibility of glaciation associated with a diamicton in the region of the Cotswold Hills known as the Bruern Till, but stresses the need for new work on this deposit.

Until recently, most archaeologists assumed that human occupation of the Dutch river area in the Neolithic period and Bronze Age was rare and predominantly seasonal. Settlement and land use were thought to be limited to abandoned alluvial ridges and aeolian dunes. However, recent archaeological research revealed that Neolithic and Bronze Age human activity occurred at many locations in the Rhine-Meuse Delta. Human settlement and agricultural land use in the Rhine-Meuse delta from at least 3200 BC to 1100 AD was much more common than previously thought. Crevasse splay complexes of active and abandoned river systems proved to have provided favourable sites for settlements. These elevated areas were suitable for agriculture, as they were fertile, easy to plough and possessed suitable hydrological conditions. In addition, people could exploit the surrounding floodplain for hunting, fishing or herding their cattle. Furthermore, the river or residual river channel was near for transport. From the start of the Middle Bronze Age B (1400 BC) occupation of crevasse splay deposits in the delta was widespread. Farmsteads were built on splays that varied in size and morphology. Some locations were abandoned after a few decades, while others remained occupied during a much longer period. During the period of occupation, the crevasse splays gradually lost their relatively high position in the landscape due to subsidence and ongoing sedimentation on the floodplain.

LIDAR data combined with digital coring databases and/or detailed soil maps have proven to be an excellent method to identify and map crevasse splays and archaeological sites on these. The resulting new maps form a major basis for archaeological prospection and preservation policy.

A single internal mould of the holasterid echinoid Holaster laevis (Brongniart, 1822) constitutes the first record of this species from the upper portion (‘Upper Holland Marl’) of the Holland Formation (Rijnland Group), of middle-late Albian age, in the Winterswijk area (eastern Netherlands). The geographic range of H. laevis can thus be extended to this part of western Europe, with previous records from southern England (Wiltshire, Devon) and the Département Ain in east-central France.

The youngest representatives of ‘true’ (= non-tegulated) inoceramid bivalves (Inoceramidae) are described from intervals 3-6 of the Vijlen Member (Gulpen Formation), of late early and early late Maastrichtian age, as exposed at quarries and temporary sections in northeast Belgium (CPL SA-Haccourt and CBR-Lixhe quarries) and the Aachen area (Germany), i.e. the extended type area of the Maastrichtian Stage. In total, twelve taxa are recognised from levels which are correlative with the Calcaire à Baculites of Manche (France), as well as with the Tercis les Bains section in southwest France, the Wisła (Vistula) River sections (central Poland) and the Western Interior of the United States. Associated cephalopods allow a detailed correlation between biozones based on those groups and on inoceramid bivalves.

The original distribution pattern of Middle-Palaeolithic artefacts may be affected by tectonic movement, sedimentation and periglacial processes. This is e.g. the case in the coversand area of Limburg and Eastern Brabant (NL), where the occurrence of numerous finds in a SW-NE trending zone across the Roer Valley Graben is considered enigmatic. In order to elucidate the processes affecting the spatial distribution and the chance of recovery of such artefacts, we investigated a site in Nederweert. At this site, several Middle-Palaeolithic artefacts had been recovered earlier from unexpectedly shallow depths. A test pit profile and grain size analyses revealed that the shallow sediments at this site have been affected by intense, multi-phase cryoturbation, which has deformed the sand and loam layers and partially mixed them thoroughly. As a result, optically stimulated luminescence dating of these sediments yielded widely scattered single-aliquot equivalent dose distributions. Using a Finite Mixture Model (FMM), it was estimated that cryoturbation caused mixing of sediments deposited between 12 and 50 ka with sediment grains deposited between 60-150 ka. The latter material is probably the original context of the Middle-Paleolithic artefacts. Apparently, cryoturbation and potentially other periglacial processes have transported artefacts closer to the surface. Based on these results, we suggest that the occurrence of Middle-Palaeolithic artefacts is caused by (1) the tectonically-induced spatial distribution of layers of this age and (2) periglacial processes having caused migration of artefacts towards the surface. Although periglacial processes may facilitate finding Middle Palaeolithic artefacts, they may severely disturb the original context to such an extent that Middle Palaeolithic sites can no longer be identified. The results of this study form a basis for improving the Indicative Map of Archaeological Values that is used to predict the presence of archaeological sites. The insights gained are also relevant to other areas where Middle-Palaeolithic sites are affected by periglacial processes.

During the 2007 ‘Kor en Bot’ collecting trip across the Oosterschelde (province of Zeeland, southwest Netherlands), on board trawler cutter ZZ10, a stem fragment of a fossil isocrinid was recognised amongst the contents of the nets pulled on deck. This specimen is here interpreted to be of Early Jurassic age and assignable to the genus Isocrinus. However, because only internodals are preserved in this pluricolumnal, specific identification cannot be but approximate (Isocrinus (Chladocrinus) cf. tuberculatus). In the absence of any outcrop of Jurassic deposits in Zeeland and adjacent Dutch and Belgian territory, the most likely explanation is that this crinoid represents erratic material transported by precursors of the present-day River Maas (Meuse). Between the Langres Plateau and Sedan (northeast France), this river cuts through several occurrences of Lower Jurassic strata from which the present isocrinid might have originated. A less likely explanation is that it stems from boulders used for coastal reinforcement or from a Roman limestone votive altarpiece put up at the temple complex for the goddess Nehalennia, formerly present at Colijnsplaat, near Domburg (Noord-Beveland, Zeeland). Transportation from either northwest France or the southern or eastern United Kingdom, where there are coastal exposures of Jurassic strata, via the North Sea, is another option which, however, is also considered less feasible in view of the good state of preservation of the crinoid.

Shell aragonite δ180 values of unionid freshwater mussels are applied as a proxy for past river discharges in the rivers Rhine and Meuse, using a set of nine shells from selected climatic intervals during the late Holocene. A single Meuse shell derives from the Subboreal and its δ180 values are similar to modern values. The Rhine specimens represent the Subboreal, the Roman Warm Period and the Medieval Warm Period (MWP). These shells also show averages and ranges of aragonite δ180 values similar to modern specimens. This indicates that environmental conditions such as Rhine river dynamics, Alpine meltwater input and drought severity during these intervals were similar to the 20th century. These shells do not record subtle centennial to millennial climatic variation due to their relatively short lifespan and the large inter-annual and intra-seasonal variation in environmental conditions. However, they are very suitable for studying seasonal to decadal scale climate variability. The two shells with the longest lifespan appear to show decadal scale variability in reconstructed water δ180 values during the MWP, possibly forced by the North Atlantic Oscillation (NAO), which is the dominant mode of variability influencing precipitation regimes over Europe.

A number of 45 presumed pingo remnants have been analysed on lithological criteria while measured parameters of pingo remnants can be compared on a spatial scale. Methods used were hand augering and radiocarbon dating. Out of 45 cored sites thirty sites proved to represent pingo remnants after having tested the results according to the set of descriptive criteria. Does a difference in filling types in a spatial analysis influence the choice of early settlers in this region? Results show that two groups of pingo remnants can be distinguished by the nature of the pingo filling. Type 1 pingo remnants with predominantly peat filling are found in the lower valleys between the higher glacial till ridges. Type 2 pingo remnants with equal loam and peat filling are predominantly found on the higher glacial till ridges. Type 2 pingo remnants generally have a greater depth, are more ellipsoid in shape, and have a steeper slope angle than type 1 pingo remnants on the lower terrain. Results indicate that the substrate character influenced the development of infilling of pingo remnants. Marshy environments may have existed for a prolonged period throughout the Holocene in pingo remnants on the glacial ridges, while pingo remnants on the lower terrain are filled in by peat bogs. Landscape evolution based on the results of a distinct dataset of pingo remnants can help to solve archaeological problems of settlement issues when combined with new palaeobotanic data and high resolution dates.

Part of the gravelly deposits of a combined Rhine-Meuse river of Middle Pleistocene age in the central Netherlands contains early Middle Palaeolithic artefacts. Although not in their original position, a significant part of these artefacts is hardly abraded, indicating limited fluvial transport. The artefacts have mainly been made from fluvial flint gravel boulders, originating from the Meuse catchment. Thus far, inferences for the age of the artefacts are based on the stratigraphic context and floral and faunal remains, which suggest a MIS 7 age. In this paper, OSL dating carried-out in the framework of a research aimed at the paleogeographical reconstruction of the Rhine-Meuse fluvial system in the central Netherlands and a review of published data are used to provide absolute age constraints for the artefact-bearing deposits. It is argued that the deposits were formed during the glacial phase directly preceding the Drenthe substage of the late Saalian (early MIS 6), and that at least a part of the artefacts has approximately the same age.