In preparation of the first paleoseismic trenching in the NE border of the Roer graben (the Netherlands), site selection was carried out. Combining geological and seismological information and using existing aerial photographs, seismic reflection and geodetic levelling data, it was decided to focus on the Peel boundary fault near the village of Neer. Detailed information on the exact location of the fault was obtained through geophysical techniques, mainly ground penetrating radar (GPR) and resistivity measurements. GPR data unambiguously showed the flexuring and offset of reflectors affected by the fault. Performing eleven GPR profiles along strike allowed to obtain a 3D picture of the fault, laterally extending the information given in the trench.

We reanalysed the induced seismicity data from the Groningen gas reservoir. We used the well-maintained induced event catalogue of the KNMI. The distributions of seismic moments and interevent times show a power law behaviour over several decades, and we find that upon increasing the magnitude threshold, these distributions remained scale-invariant. Because of this scale-invariance, we can put a constraint on the average loading of the elastic energy within the reservoir, which upon reaching a critical value gives rise to the seismic events. We find that the elastic energy roughly increases proportional to time. We also propose a new machine learning approach for declustering the seismic events, separating correlated from independent events. We find that only few events are truly independent, i.e. exponentially distributed over time. There are also few aftershocks following an Omori-type power law. The bulk of events presents a Gamma distribution for interevent times. This gives us an indication that the rigidity in the reservoir is high, but whether this results in overall correlated events should be settled with physics-based arguments rather than statistical ones.

The positive impact that natural fractures can have on geothermal heat production from low-permeability reservoirs has become increasingly recognised and proven by subsurface case studies. In this study, we assess the potential impact of natural fractures on heat extraction from the tight Lower Buntsandstein Subgroup targeted by the recently drilled NLW-GT-01 well (West Netherlands Basin (WNB)). We integrate: (1) reservoir property characterisation using petrophysical analysis and geostatistical inversion, (2) image-log and core interpretation, (3) large-scale seismic fault extraction and characterisation, (4) Discrete Fracture Network (DFN) modelling and permeability upscaling, and (5) fluid-flow and temperature modelling. First, the results of the petrophysical analysis and geostatistical inversion indicate that the Volpriehausen has almost no intrinsic porosity or permeability in the rock volume surrounding the NLW-GT-01 well. The Detfurth and Hardegsen sandstones show better reservoir properties. Second, the image-log interpretation shows predominately NW–SE-orientated fractures, which are hydraulically conductive and show log-normal and negative-power-law behaviour for their length and aperture, respectively. Third, the faults extracted from the seismic data have four different orientations: NW–SE, N–S, NE–SW and E–W, with faults in proximity to the NLW-GT-01 having a similar strike to the observed fractures. Fourth, inspection of the reservoir-scale 2D DFNs, upscaled permeability models and fluid-flow/temperature simulations indicates that these potentially open natural fractures significantly enhance the effective permeability and heat production of the normally tight reservoir volume. However, our modelling results also show that when the natural fractures are closed, production values are negligible. Furthermore, because active well tests were not performed prior to the abandonment of the Triassic formations targeted by the NLW-GT-01, no conclusive data exist on whether the observed natural fractures are connected and hydraulically conductive under subsurface conditions. Therefore, based on the presented findings and remaining uncertainties, we propose that measures which can test the potential of fracture-enhanced permeability under subsurface conditions should become standard procedure in projects targeting deep and potentially fractured geothermal reservoirs.

The Groningen field is the largest onshore gas field in Europe. Continuous production since 1963 has led to induced seismicity starting in the early 1990s. Production measures aimed at lowering the level of seismicity have been implemented since 2014. In this paper we start from an empirical relationship between the cumulative number of seismic events and cumulative gas production. We show that a better way to analyse the data is to relate the ratio of activity rate over production rate versus the cumulative production, such that the model parameters and their uncertainty can be determined. This also allows us to make predictions including the confidence intervals.

Using this model, we first performed regression analysis based on the larger seismic catalogue which includes all recorded events with a magnitude of 1.3 and larger, because we consider this value to be the magnitude of completeness since 1995. We have also performed regression analysis based on a smaller seismic catalogue consisting of all events with a magnitude of 1.5 and larger. This was done in order to be able to compare our forecast with forecasts performed by others. Our prediction for 2016, based on the seismic catalogue of all events with a magnitude of M≥1.5 (using only the events recorded before 2016), was 16±8 events. By the end of 2016, 13 such events had been recorded.

We discuss a number of factors which may influence the predictive power of the derived relationship and which require further study. For instance, we consider the delay between production and earthquakes which increases with decreasing reservoir pressure. In addition, the effect of seasonal fluctuation in Groningen production should be considered. Future work can be done to include these effects in the empirical model. We also investigated the challenges related to the applicability of the analysis to sub-regions of the Groningen field.

The current status of knowledge concerning the Eemian interglacial in Sweden is surveyed, and comparisons are made with northern and western Finland. The course of shore displacement is fragmentarily known for Sweden, since brackish-marine sediments have been identified, on the basis of diatom analysis, at only few sites. In Finland, on the other hand, a shoredisplacement curve has been constructed for the Eemian Baltic Sea in Ostrobothnia, central western Finland.

The vegetation history is summarised for the southernmost part of Sweden, and can be correlated with that documented in Denmark. For the central part of Sweden, information is sparse, but the composition of the forests has been outlined for most of the interglacial, although information on regional pollen assemblage zones E3 and E4 (early-temperate substage) are mainly missing. A more complete picture of the interglacial vegetational history is known from Ostrobothnia in Finland. The thermophilous indicators Viscum, Ilex, Hedera and Osmunda grew far North during the Eemian. Corylus and Carpinus expanded much further to the North than during the Holocene. In Swedish and Finnish Lapland, the vegetation history is similar except that Larix was common in Finland during the Eemian, but its presence has so far not been confirmed in Sweden.

Eemian deposits relocated during the Weichselian glaciation contain pollen and diatoms that can be used for reconstruction of the Eemian environment. No clear indication of a rapid climatic deterioration during the Eemian has been found so far in either Swedish or Finnish sequences.

The extent of regional variability in vegetation development in mainland Greece during the last interglacial is considered. Three pollen sequences – Ioannina (northwest Greece),Tenaghi Philippon (northeast Greece) and Kopais (central Greece) – all located in different environmental settings, extend into the last interglacial. Examination of the vegetation histories of the three sites during the last interglacial reveals the influence of local climatic conditions with closed mixed forests in the northwest, becoming progressively more open and less diverse farther to the east and south. All three sequences contain a number of similar trends, however, in the expansion of certain taxa. In addition, they also show the presence of a two-step late glacial interval, a short episode of forest reduction in the second part of the interglacial and a final small expansion of tree populations at the very end of the interglacial. Comparison with other European records shows a number of common features, but also suggests differences consistent with the particular environmental setting of the Greek sites.

The history of this volume goes back to a 1973 INQUA congress in New Zealand, where an INQUA Commission of Stratigraphy working group on major subdivisions of the Pleistocene was established. The Pleistocene series/epoch was hitherto generally subdivided into the Lower/Early, Middle and Upper/Late Pleistocene (see, among others, Zeuner, 1935, 1959) but the boundaries between these subseries/subepochs were not formally defined. The boundary between the Early and Middle Pleistocene was, in the European literature, put at the base of the Cromerian Complex (Zagwijn, 1963) or at the Brunhes/Matuyama magnetic boundary (Richmond, 1996).

We highlight a watershed in the natural gas legacy of the Netherlands: after 50 years of successful gas development, production output of conventional fields will decline from 2010 onwards. The projected decline in Dutch gas output will lead to a loss of future income for the State. In the past, E&P companies were prepared to compete for access to Dutch assets and lead in research as well as in the exploration for the development of conventional gas resources. Today, this cannot be assumed for the development of unconventional resources. It is not clear from our current state of knowledge whether the riskier unconventional gas resources in the Netherlands will be attractive for E&P companies. For example, are the financial risks for maturing potential unconventional resources into economic proved reserves acceptable to them? The US boom in unconventional gas production was preceded by government sponsored research programmes that stimulated the development of unconventional gas production technology. Decline in domestic gas production in the Netherlands therefore prompts for a dedicated upstream gas research programme. This will help to unlock future value from stranded conventional gas and unexplored unconventional gas resources. If such new gas resources can indeed be developed with the aid of research, undue loss of state income can be mitigated, which makes such a programme a compelling business case.

New specimens described herein add to our knowledge of uncommon parataxa (embedment structures, borings and a certain type of burrow) from the type area of the Maastrichtian Stage, the material originating from the ENCI-HeidelbergCement Group (Maastricht), Ankerpoort-'t Rooth (Bemelen) and former Blom (Berg en Terblijt) quarries in southern Limburg (the Netherlands), and from the CBR-Romontbos (Eben Emael) and CPL SA (Haccourt) chalk pits in the province of Liège (northeast Belgium). Although Centrichnus eccentricus Bromley & Martinell has previously been recorded from this area, it has not received formal description; the specimen documented herein shares a test of the echinoid Echinocorys gr. conoidea with numerous other episkeletozoans. Podichnus cf. centrifugalis Bromley & Surlyk occurs both on echinocorythid echinoid tests and guards of belemnitellid coleoids; two out of seven specimens display radial discontinuous channels, indicative of the extreme penetration of filaments from the attached brachiopod's pedicle. Renichnus arcuatus Mayoral shows a range of morphologies, from the embedment structure sensu stricto through to specimens retaining internal moulds of the producing, embedded vermetid gastropod to free shells of Vermetus binkhorsti Cossmann. Burrows packed with bioclastic debris, particularly primary spines and a few test plates of phymosomatid echinoids, present a systematic conundrum, although appearing comparable to the ichnogenera Nummipera Hölder and Baronichnus Breton in several respects.

Two unusual bumps occur on the internal surface of a rib of the marine reptile Prognathodon saturator from the Upper Cretaceous (Maastrichtian) of Maastricht, The Netherlands. These bumps are interpreted as stress fractures, possibly related to agonistic behaviour.

Paleoseismological investigations have been performed at Mt. Baldo and in the Lessini Mts. in order to collect quantitative data on the activity of minor faults showing geomorphic evidence of recent activation. The 4.5-km-long, NNE-SSW trending Naole fault was responsible for the formation of a narrow depression at the top of Mt. Baldo, bordered by a continuous bedrock (carbonate) fault scarp to the west. The extensional activity along this minor fault is probably due to gravitational deformations (lateral spreading) in response to the warping of the Mt. Baldo anticline. A 1.5-km-long graben is instead related to the 2.5-km-long, NNW-SSE trending Orsara fault (Lessini Mts.) which was responsible for the formation of bedrock (carbonate) fault scarps. This minor fault is part of a complex structural framework made of few-km-long faults which show evidence of Quaternary activity. Two trenches have been excavated across the Naole fault which showed the occurrence of displacement events subsequent to 17435-16385 BP (cal. age) and probably prior to 5455-5385/5330-5295 BP (cal. age). Two other trenches have been excavated across the Orsara fault whose analysis indicated that the most recent displacement event occurred between 20630-19795 BP and 765-675 BP (cal. age). The upper chronological limits of the displacements give some indications about the minimum elapsed time since the last fault activation (about 5,300 years for the Naole fault and 5-8 centuries for the Orsara fault). Both 1) the maximum expected magnitude of the earthquakes which may originate along the Mt. Baldo thrust and 2) the identification of a main fault responsible for the displacements along the complex net of minor faults affecting the Lessini Mts. are still open questions. As for point 1 although historical earthquakes with magnitude 4.5-5 may be associated with the Mt. Baldo thrust, the investigations carried out in this area did not clarify whether larger magnitude earthquakes may be expected. As for point 2, the cause of the displacements along the Orsara (Lessini Mts.) fault may be related to the activity of a major blind fault (which, however, has never been identified), responsible for the uplift of the Lessini Mts. More generally, the obtained results demonstrate the limits of traditional paleoseismological analyses in Alpine areas whose erosional/depositional activity has been strongly conditioned by the Late Pleistocene glacial history. The lack of units younger than loess and colluvial sediments related to the Last Glacial Maximum makes it impossible to define narrower chronological constraints for the displacements and to estimate the number and size of the displacement events. Moreover, the rebound following the retreat of the thick glacial cover affecting the Alpine area may have induced stresses responsible for higher deformation rates after the Last Glacial Maximum. Higher surficial deformation rates could imply shorter recurrence intervals for faulting episodes and/or larger magnitude earthquakes. Therefore, paleoseismologically inferred data in Alpine areas may not correctly define the fault behaviour related to the present tectonic regime.

The first occurrence (FO) of the ammonite Pachydiscus neubergicus (von Hauer, 1858) has been correlated to calcareous nannofossil zonations in several European sections along the northern margin of the Tethyan palaeobiogeographic realm. Both the proposed stratotype section of Tercis (SW France) and complete, ammonite-bearing sections in northern Spain document the FO of P. neubergicus within standard nannofossil zone CC23a (UC16), below the LO of Broinsonia parca constricta. Other sections such as the type locality Neuberg (Austria), Nagoriani (the Ukraine) and Bjala (Bulgaria) indicate considerable diachroneity of local FOs and show P. neubergicus to range up to nannofossil zone CC25b/c (UC20; Late Maastrichtian).

The Late Pleistocene Wijchen Member (WM) and its informal stratigraphic precursors have been recognized for decades in the Rhine-Meuse Valley of the Netherlands. Although the WM marks the top of the Kreftenheye Formation (KF) at the boundary between Pleistocene and Holocene lithofacies and provides a confining bed for the regional alluvial aquifer, significant issues remain regarding WM depositional environment and processes of sedimentation. Regional WM chronology suggests a time-transgressive, millennium scale response of the Rhine River to Lateglacial climate oscillations. This paper compares interpretations of sedimentation process, stratigraphic pattern, and paleoenvironmental significance to prevailing viewpoints on the WM mode of origin.

A flood basin in the Over Betuwe between the channel belts of the Neder Rijn and River Waal is investigated to characterize WM stratigraphy. The KF braided stream deposits (Kb) form a regionally extensive sandy to gravelly lithofacies. As Kb aggradation ceased, fluvial channels incised into local braid plain swales. The WM was deposited during episodes of fluvial activity as a suspended load mud drape across segments of the abandoned braid plain. The WM is a gray silty lithofacies that also contains local admixtures of sand. Explanations for the origin of the sand admixed into the mud include variability in hydrodynamic load across the flood plain, eolian mixing, and/or biogenic mixing. In the study area, eolian deposition of sand onto a wet flood plain surface is the most probable cause for the admixed sand fraction. Pedogenesis of the WM in the study area is limited to gleying under reduced wetland conditions and the development of organic rich vegetation horizons that formed on top of relatively unaltered fluvial strata. Similar reduced soil properties and limited pedogenic development occur downdip to the present coast, but updip of the study area, the WM is the parent material for poorly drained to well drained and oxidized profiles that range from Entisols to weakly expressed Alfisols.

The presence of pumice granules in Kb deposits of the study area indicate that channel belt deposition continued after the Laacher See volcanic eruption in Germany at ~12,900 cal yr. Deposition of the WM occurred episodically throughout the Lateglacial and terminated by the early Holocene. The time interval between the end of WM deposition and subsequent burial by flood basin peat reflects a duration of exposure of at least 3500 yrs. Since regional water table rise affected the area ~5000 cal yrs ago, the early Holocene water table must have been maintained by spring fed ground water sources from nearby ice pushed ridges.

Deposition of the WM is associated with transitional braided to meandering fluvial channels during times when the Rhine-Meuse Valley experienced a sensitive response to rapid climate change. The WM is regionally time transgressive and probably formed during flood plain transitions between permafrost and base-flow driven hydrologic regimes. Regional landscape dynamics suggest that WM deposition and subsequent preservation was driven by fluctuations of the southern limit of permafrost during Northern Hemisphere deglaciation.

During recent years, regular round structures have been collected from the top of Bed 12 of the Vossenveld Formation (Lower Muschelkalk, lower Middle Triassic, Anisian) in the Winterswijk area, eastern Netherlands. These are here illustrated and described as probable remains of jellyfish.

Recent carried out core drillings in the Ludwigshafen/Speyer area permit an improved stratigrahical differentiation of the Plio-Pleistocene deposits in the northern Upper Rhine Graben. Lithofacies analysis, pollen analysis, heavy mineral analysis, and palaeomagnetical results, lead to a subdivision of ‘Kieslager’ (gravel-layers) and ‘Zwischenhorizonte’ (interlayers). In the scope of geological mapping near Mannheim and Speyer, the genesis and the stratigraphic position of Middle and Late Pleistocene fluvial terraces was re-assessed (‘Frankenthaler Terrasse’). The terrace has a complex composition, marking two phases of accretion followed by abandonment: a first phase took place in (Elsterian? to) Saalian times, the second phase during the Weichselian. Tectonism further complicates the sequence, in particular in the area between Ludwigshafen and Speyer, which is the SW rim of the ‘Heidelberger Loch’-structure. In this area ‘terraces’ occur they are the result of faulting rather than fluvial dissection alone.

In the Netherlands the present-day thermal gradient in the shallow subsurface (i.e. the upper few 100 m), is around 20°C km–1, whereas at depths between 0.5 and 3 km it is ∼33°C km–1. This large contrast in the gradient between shallow and deeper parts of the subsurface occurs throughout the country and cannot be explained by either systematic thermal property changes with depth or the depositional setting of the region. In this paper we use a 1D thermal model for the crust and demonstrate that this observed temperature-depth trend most likely reflects a transient condition inherited from past climate change. It is shown that the prolonged cold period during the Weichselian (∼110–10 kya) and the subsequent warmer conditions during the Holocene account for the increase in the thermal gradient with depth. Moreover, we demonstrate that thermal history further back in time still influences the present-day subsurface temperature. Geothermal climate-change influences on these long time scales have not been documented before for the Netherlands.

Tidal inlets and the associated ebb-tidal deltas can significantly impact the coastal sediment budget due to their ability to store or release large quantities of sand. Nearly 300 million m3 (mcm) of sediments were eroded from Texel Inlet's ebb-tidal delta and the adjacent coasts following the closure of the Zuiderzee in 1932. This erosion continues even today as a net loss of 77 mcm was observed between 1986 and 2015. To compensate, over 30 mcm of sand has been placed on the adjacent coastlines since 1990, making maintenance of these beaches the most intensive of the entire Dutch coastal system.

Highly frequent and detailed observations of both the hydrodynamics and morphodynamics of Texel Inlet have resulted in a unique dataset of this largest inlet of the Wadden Sea, providing an opportunity to investigate inlet sediment dynamics under the influence of anthropogenic pressure. By linking detailed measurements of bathymetric change to direct observations of processes we were able to unravel the various components that have contributed to the supply of sediment to the basin, and develop a four-stage conceptual model describing the multi-decadal adaptation of the ebb-tidal delta.

Prior to closure of the Zuiderzee a dynamic equilibrium state (stage 1) existed with a stable ebb-tidal delta. The largest morphological changes occurred in roughly the first 40 years since the closure, and were dominated by the rotation and scouring of large tidal channels and landward retreat of the Noorderhaaks ebb shoal (stage 2; adaptation). Between 1975 and 2001 the general layout of main channels and shoals was stable, but large sediment losses continued to occur (stage 3; equilibrium erosional state). Since 2001, the erosion rates have significantly reduced to 2 mcm a−1 (stage 4; stabilisation).

Twenty-five years of data on ‘Dynamic Preservation’ prove that sand nourishments are well capable of keeping the coastlines adjacent to the Texel Inlet in place. Moreover, the abundant supply of sediment may also have compensated for the sediment losses on the larger scale of the southern part of the ebb-tidal delta, resulting in a recent stabilisation of its volume. This response illustrates the potential benefits of Dynamic Preservation not only for coastline resilience but also on the larger scale of the inlet system. Such knowledge is essential for future preservation, management and maintenance of inlet systems in the scope of climate change and accelerated sea-level rise.

From 1998 to 2000, we have studied the evidence for large paleoearthquakes at the Rurrand Fault. This fault represents the eastern border of the Roer Valley Graben, which is the tectonically most active region in the Lower Rhine Embayment. The purpose of our paleoseismological studies is to enlarge the seismicity data base for this region beyond instrumental records and historical reports using indications of surface-faulting events from stratigraphie conditions at active faults. Larger time spans considered in the earthquake catalogue will enable a more reliable statistical analysis which is required for seismic hazard assessment. Based on analyses of geological data and géomorphologie investigations, detailed geophysical surveying was carried out along the southern Rurrand Fault segment for the selection of a site appropriate to paleoseismological studies. Mapping of physical parameter contrasts with seismic reflection, VES, ERT, and GPR measurements along fault-crossing profiles inferred position and near-surface structure of the fault. At the site promising the best conditions, a trench was excavated across the fault near the city of Jiilich, Germany. Within a depth of about 4 m, the Rurrand Fault was exposed in an about 50 m-wide system of faults and fault zones, affecting the stratigraphie sequence with various displacement characteristics and amounts of throw. According to heavy mineral analyses, the deposition time of most the exposed sediment strata was assigned to Pliocene and Lower Pleistocene time. These geological units are covered by loess layers deposited through so-lifluction processes during the Weichselian glacial, i.e. some tens of ka B.P., or – with lower probability – during the Saalian glacial. Several faults which had also affected the loess reflect younger fault activity. However, clear paleoseismic features were not observed in the trench, thus an unambiguous proof of the occurrence of coseismic fault displacements could not be furnished. Recently, differential subsidence due to drainage takes place in the surroundings of the nearby opencast mining. An amount of some 0.35 m, concentrated in a very narrow lateral zone, has been observed during the last 40 a at about 1 km distance from the trench position. To date, the subsidence could not be clearly located in the trench exposure. Results from geodetic levelling campaigns will help to determine the offset residuals and to gain better insight into the ruling displacement processes at the Rurrand Fault.

Biostratigraphical re-analysis of palaeobotanical data from the De Lutte-06 well clarifies an earlier controversy regarding the stratigraphical interpretation of this well based on palaeobotanical and palynological analysis. Previous biostratigraphical studies suggested an early Westphalian D age for the major part of the De Lutte formation, with only at the topmost part of the well remnants of presumable but unconfirmed Stephanian deposits. New identifications of palaeobotanical samples illustrate the presence of plant macrofossil assemblages in the De Lutte Formation characteristic for the latest Westphalian D to the Stephanian B-C. These new palaeobotanical insights, therefore, confirm a younger age for the De Lutte Formation and are more in line with the earlier palynological observations from the De Lutte-06 well that suggested that the recovered palynofloras resembled typical Stephanian associations.