Major efforts are being undertaken to quantify seismic hazard and risk due to production-induced earthquakes in the Groningen gas field as the basis for rational decision-making about mitigation measures. An essential element is a model to estimate surface ground motions expected at any location for each earthquake originating within the gas reservoir. Taking advantage of the excellent geological and geophysical characterisation of the field and a growing database of ground-motion recordings, models have been developed for predicting response spectral accelerations, peak ground velocity and ground-motion durations for a wide range of magnitudes. The models reflect the unique source and travel path characteristics of the Groningen earthquakes, and account for the inevitable uncertainty in extrapolating from the small observed magnitudes to potential larger events. The predictions of ground-motion amplitudes include the effects of nonlinear site response of the relatively soft near-surface deposits throughout the field.

Uphill and drainage line environments reveal many hiatuses or discordances, because of truncation by erosion. In downslope position accumulation often prevailed outside the drainage lines and prevented erosion, even during unstable periods. Consequently, downslope sections yield the most detailed environmental data, but often lack contact with uphill series. However, for stratigraphical correlation the contact between downslope and uphill series is essential. In the Veldwezelt loess sequence this contact is intact, which provides additional data on transitional processes. In view of these special palaeoenvironmental conditions, exhibiting a transition between downslope and uphill areas and a south-east trending stream, an extraordinarily detailed Late Saalian, Eemian and Weichselian loess sequence could be reconstructed. The Veldwezelt series furnished important pedological, sedimentological, faunal, tephrochronological and cryogenic data, on the basis of which palaeoenvironmental conclusions could be drawn and six types of pedo-sedimentological cycles distinguished. A stratigraphical overview was obtained by correlating the Veldwezelt section with other west European loess frameworks and tephra sequences; the sedimentary series at Harmignies (Mons Basin, southern Belgium) and the Greenland GRIP ice core.

Ground-penetrating radar data from a regular grid are used to study the internal structure and development of a 9-m high aeolian river dune in the Dutch Rhine-Meuse delta. The purpose of this investigation was to image the internal sedimentary structures to better understand the development of these aeolian river dunes. Three radar facies can be recognised in the GPR sections. Radar facies 1 has a maximum thickness of 5 to 6 m and is characterised by dipping, parallel reflections with a maximum length of at least 20 m. The reflections from perpendicular sections, analysed using closed-loop correlation in 3-D-interpretation software, form eastward dipping (14° maximum) surfaces. Radar facies 2 is one continuous, sub-horizontal reflection. This high amplitude reflection is most probably caused by a thin organic horizon. Radar facies 3 has a thickness of 3 to 4 m and is made up of sets of short, predominantly eastward to north-eastward dipping reflections separated by rather continuous, sub-horizontal reflections. The eastward dipping surfaces in radar facies 1 are foresets of a dune that was deposited by prevailing westerly winds in the Younger Dryas, the last cold period in the Pleistocene. During the Early Holocene, an increasing vegetation cover stabilised the dune and formed a thin organic horizon. Subsequent resumption of dune forming processes led to the formation of radar facies 3 on top of the vegetated Pleistocene dune. Sedimentation by small dunes, partly eroding each other, led to sets of cross-stratification separated by bounding surfaces. The results suggest a small change in palaeo wind direction.

In 1992, the well L9-7, drilled by the Nederlandse Aardolie Maatschappij (NAM) unexpectedly found a thick previously unknown sandstone interval with excellent reservoir characteristics in the Middle Buntsandstein (Triassic) of the Dutch Northern Offshore: the ‘Fat Sand’. A follow-up well, L9-8, found this reservoir gas-bearing in an accumulation that turned out have recoverable reserves of circa 1 Tcf of gas distributed over several fault compartments. This serendipitous discovery led to a frantic period in NAM's office trying to understand the setting of this local sand development and, most importantly, assess follow-up potential; could this sand be present elsewhere in a trapping configuration? The local depocentre in which the Fat Sand accumulated is considered to be caused by local extension along a strongly listric fault soling out on the top of the Zechstein Salt. This supra-salt fault seems to be caused by early east-west extension in the Dutch northern offshore. The shape of the fault plane was strongly influenced by the presence of the nearby Zechstein Salt, and by early salt flow, which was also triggered by E-W extension.

Present study provides a review of the latest results on fluvial and aeolian landscape evolution in Hungary achieved by our team during the last 20 years.

– The Hungarian river terrace system and its chronology was described with special emphasise on the novel threshold concept. A revised terrace system was created by the compilation of novel terrace chronology and MIS data. Evolution of river terraces was not only governed by climatic factors but tectonic ones too. Incision rate of the Danube, and uplift rate of the Transdanubian Range (TR) was around 0.1-0.3 mm/a in the marginal zones of the TR (mostly based on the published U-series data) and was above 1 mm/a in its axial zone (based on 3He exposure age dating of strath terraces).

– According to a detailed geomorphological investigation of the different channel-planform morphologies in the Middle Tisza region and Sajó-Hernád alluvial fan, six phases of river pattern change and four incision periods were detected during the last 20,000 years.

– Wind polished rock surfaces dated by in situ produced cosmogenic 10Be suggest that deflation was active in Hungary as early as 1.5 Ma ago. According to these exposure age data, Pleistocene denudation rate of the study area (Balaton Highland) was 40-80 m/Ma.

– In sand covered areas the alternations of wind-blown layers and buried fossil soils provide information about climate and environment changes. In this study, periods of sand movement were mostly determined by optically stimulated luminescence (OSL) dating methods and five aeolian sand accumulation periods were recognised during the last 25 000 years.

– A new loess stratigraphical view was elaborated using the most recent dating methods (luminescence, AAR). The lower part of Mende Upper (MF1-2) pedokomplex is suggested to represent the last interglacial period (MIS 5e). During the last interglacial/glacial period (MIS 5 - MIS 2) several soil-forming periods existed but the preservation of these paleosoils is variable depending on their paleogeomorphological position.

Collecting sea-level data from restricted coastal areas is essential for understanding local effects on relative sea level. Here, a revised relative mean sea-level curve for the area of the East Frisian island Langeoog, northwestern Germany, for the time period from 7200 cal BP until Recent is presented. The revision is based on the reinterpretation of previously published and unpublished data following the HOLSEA standardisation of data handling. Altogether 68 sea-level data taken from 32 cores and outcrops from Langeoog, its back-barrier and the adjacent mainland, which have been collected since the 1950s for mapping and landscape reconstruction purposes, are presented. The age constraints, derived from radiocarbon ages of basal peat, intercalated peat and molluscs and optical dating of tidal deposits, were evaluated in terms of the HOLSEA sea-level protocol and their stratigraphic context. For 7200 cal BP until modern times, 30 sea-level index points with different uncertainty ranges were defined. Additionally, a factor of decompaction was estimated for the remaining basal peat samples as well as for the underlying sediments of intercalated peat samples.

The comparison of the Langeoog relative sea-level curve with the relative sea-level curve from the western Netherlands shows that the Langeoog curve lies up to 0.80 m lower than the Dutch curve and diverges for the time before 6000 cal BP. Though the offset coincides with the overall predicted trend of glacial-isostatic adjustment, it is less than predicted.

Our study provides a useful assessment of legacy data and contributes to an improved sea-level index dataset for the southern North Sea coast.

The Groningen field is the largest onshore gas field in Europe. The gas-bearing section comprises aeolian and fluvial Rotliegend sandstones of Permian age and fluvial sandstones of Carboniferous age. Continuous production since 1963 has led to induced seismicity starting in the early 1990s.

Faults at reservoir level play a major role in the seismicity in the Groningen field. Fault slip is expected when shear traction is sufficient to overcome frictional resistance on the fault surface. Clear insights into which faults and fault segments are most susceptible to seismicity could be used to optimise production and minimise the seismic risk. To gain these insights, a detailed and realistic fault model is required as input to both statistical analyses on seismicity and deterministic geomechanical modelling of seismogenic behaviour along fault planes. Geometrical seismic attributes and, subsequently, fault planes were extracted from a reprocessed and depth-imaged 3D seismic volume. This resulted in a detailed visualisation of the faults at reservoir level, with extension into the deeper strata below the reservoir in many cases. They represent fault planes with realistic dimensions and shapes. The fault map based on seismic attributes suggests the presence of faults that have not been included in studies on Groningen seismicity before. The improved fault definition correlates with recent earthquake hypocentres. We conclude that a detailed fault model of the Groningen field can be created using 3D seismic attributes and that detailed 3D fault planes can be extracted from these attributes. The results can be used as input to statistical and geomechanical analyses on seismicity.

The inner Atlantic Coastal Plain of New Jersey reveals exposures of fossiliferous Maastrichtian and Danian deposits. Recent fossil discoveries in this interval are here reported, and placed in the context of Cretaceous/Tertiary (K/T) faunal changes. The exposure at the Inversand Pit at Sewell (New Jersey) is the last active marl mine in the region, and stands as an important reference section for the many significant discoveries of vertebrate fossils produced by the marl mining industry at its zenith. Changes in planktonic populations across the K/T boundary are related to Maastrichtian/Danian marine ecosystem community reorganisation, by demonstrating changes in abundance of dominant marine invertebrates in successive fossil assemblages. Marine invertebrates with non-planktotrophic larval stages were briefly the commonest fossils preserved in the Danian sediments of this region. Late surviving examples of Cretaceous fauna now restricted to the Indo-Pacific region may imply biogeographic changes linked to the K/T mass extinction event.

The chronostratigraphic position of aeolian dunes in East Flanders (Belgium) has been under debate for decades. Until now, the only available age information consisted of a limited number of radiocarbon dates, which provided indirect sediment deposition chronologies. This paper reports on the first direct determination, by quartz-based single-aliquot optically stimulated luminescence dating, of the time that dune sands were deposited along the Lower River Scheldt in Belgium. The sediments are dated at 12.0±0.9 ka (n = 5), which confirms that the time of inland dune formation in East Flanders dates from the Younger Dryas period and should not be constrained to the Holocene.

A stacked aeolian sequence with intercalated soils is presented from the southern Netherlands, which fully covers the Late Weichselian and Holocene periods. An integrated sedimentological (sedimentary structures, grain size), palynological (pollen) and dating approach (radiocarbon, optically stimulated luminescence (OSL)) was applied to unravel climatic and human forcing factors. The dating results of soils and sediments are compatible, and no large hiatuses between the radiocarbon-dated top of the soils and OSL-dated overlying sands were observed. It is argued that the peaty top of wet-type podzols can be used for reliable radiocarbon dating. This study reveals more phases than previously known of landscape stability (Usselo Soil and two podzol soils) and instability (Younger Coversand I and II, two drift-sand units) that are related to Late Weichselian climate change and Holocene human occupation. Regional aeolian deposition in source-bordering (river) dunes (Younger Coversand II) took place in the second part of the Younger Dryas, after 12.3 ka cal. BP, implying a delayed response to Younger Dryas cooling, vegetation cover decline and river pattern change of the Scheldt. The onset of podzolisation and development of ericaceous vegetation occurred prior to the introduction of Neolithic farming, which is earlier than previously assumed. Early podzolisation was followed by a short phase of local drift-sand deposition, at c.5500 cal. BP, that possibly relates to agriculture. Strong human impact on the landscape by deforestation and agriculture resulted in a second phase of widespread drift-sand deposition covering the younger podzol soil after AD 1000.

Airborne electromagnetics (AEM) is an effective technique for geophysical investigations of the shallow subsurface and has successfully been applied in various geological settings to analyse the depositional architecture of sedimentary systems for groundwater and environmental purposes. However, interpretation of AEM data is often restricted to 1D inversion results imaged on resistivity maps and vertical resistivity sections. The integration of geophysical data based on AEM surveys with geological data is often missing and this deficiency can lead to uncertainties in the interpretation process. The aim of this study is to provide an improved methodology for the interpretation of AEM data and the construction of more realistic 3D geological subsurface models. This is achieved by the development of an integrated workflow and 3D modelling approaches based on combining different geophysical and geological data sets (frequency-domain helicopter-borne electromagnetic data (HFEM), time-domain helicopter-borne electromagnetic data (HTEM), three 2D reflection seismic sections and 488 borehole logs). We used 1D inversion results gained from both HFEM and HTEM surveys and applied a 3D resistivity gridding procedure based on geostatistical analyses and interpolation techniques to create continuous 3D resistivity grids. Subsequently, geological interpretations have been performed by combining with, and validation against, borehole and reflection seismic data. To verify the modelling results and to identify uncertainties of AEM inversions and interpretation, we compared the apparent resistivity values of the constructed 3D geological subsurface models with those of AEM field measurements. Our methodology is applied to a test site near Cuxhaven, northwest Germany, where Neogene sediments are incised by a Pleistocene tunnel valley. The Neogene succession is subdivided by four unconformities and consists of fine-grained shelf to marginal marine deposits. At the end of the Miocene an incised valley was formed and filled with Pliocene delta deposits, probably indicating a palaeo-course of the River Weser or Elbe. The Middle Pleistocene (Elsterian) tunnel valley is up to 350 m deep, 0.8–2 km wide, and incised into the Neogene succession. The unconsolidated fill of the Late Miocene to Pliocene incised valley probably formed a preferred pathway for the Pleistocene meltwater flows, favouring the incision. Based on the 3D AEM resistivity model the tunnel-valley fills could be imaged in high detail. They consist of a complex sedimentary succession with alternating fine- and coarse-grained Elsterian meltwater deposits, overlain by glaciolacustrine (Lauenburg Clay Complex) and marine Holsteinian interglacial deposits. The applied approaches and results show a reliable methodology, especially for future investigations of similar geological settings. The 3D resistivity models clearly allow a distinction to be made between different lithologies and enables the detection of major bounding surfaces and architectural elements.

Based on recent studies, the impact of global sea-level and climate change on the paleogeographic and sedimentary evolution of the Tertiary of the Lower Rhine Basin is analysed. It is shown that major changes in global climate and sea-level, such as the high-stand during the Middle Miocene climate optimum, the extreme low-stands near the base of the Tortonian and within the Messinian, are clearly reflected in the sedimentary succession. Continental climate curves, as reconstructed from Tertiary macrofloras of the Lower Rhine Basin, can be correlated with the marine, long-term isotope record. As shown by the analyses, a warm and humid climate with mean annual temperatures above 13°C and mean annual precipitation not below 1000 mm, persisted throughout the Late Miocene to Early Pliocene. Continental, high-resolution, climate data show that Late Miocene alternations of lignites and elastics are rather caused by tectonic and sedimentary processes (such as the repeated migration of the river system) than by major climate changes.

Pleistocene strata of the Wadden Sea region are mostly covered by an up to 10m thick sediment wedge deposited during the Holocene transgression. However, tidal inlets cut deep into the Holocene succession, causing Middle Pleistocene to early Holocene glacial and interglacial deposits to outcrop at the channel bottom. To investigate how the lithological properties and/or morphologies of these deposits affect the development of Holocene tidal inlets (e.g. limiting erosional processes), we analysed a series of eight cores to verify three high-resolution sub-bottom transects – and thus – to extend point-based data over a broader area. Furthermore, eight additional new cores (16 WASA cores in total), and 14 reinterpreted cores from the LBEG (Geological Survey of Lower Saxony) log database, were correlated to generate three short cross-sections at the transition from the tidal inlet (Riffgat channel) to the island of Norderney, revealing a number of new aspects for the reconstruction of the Pleistocene palaeoenvironments, i.e. the last two glacials (Saalian and Weichselian) and interglacials (Holsteinian? and Eemian). A succession of Middle Pleistocene lacustrine delta deposits, belonging either to the Holsteinian or the Dömnitz temperate stage, suggests the presence of Elsterian tunnel valleys located below the island. Furthermore, we verified the presence of an Eemian mixed tidal-flat system overlain by an Eemian sand tidal flat below the western head of Norderney which is, in contrast to suggestions from previous studies, not fully eroded in this area. Finally, we demonstrate that the Saalian moraine (Drenthe Main Till) functions as a limiting constraint in the vertical development of the Holocene/modern Riffgat channel. Our results provide a better understanding of the Quaternary stratigraphy of the central Wadden Sea as well as the influence of the subsurface geology on the architecture and evolution of tidal channels.

The shift from the coldYounger Dryas phase to the relatively warm Pre-boreal at~l 1.5 thousand years BP occurred within 50 calendar years and represents a clear example of rapid climate warming. Geologists and palaeo-ecologists have extensively studied the impact of this shift on the environment in The Netherlands. The global atmospheric general circulation model of the Max-Planck-Institute for Meteorology is applied to perform simulations of the Younger Dryas and Pre-boreal climates. Here detailed results are presented for the grid-cell representing The Netherlands, providing quantified estimates of climatic means and extremes for both periods. The results suggest that the Younger Dryas climate was characterised by cold winters (temperatures regularly below -20 °C) and cool summers (13-14 °C), with a high inter-annual variability, strong fluctuations in temperature, frequent storms and snowfall from September to May. The Pre-boreal climate was a ‘continental’ version of present-day climate, with cooler winters, warmer summers (~2 °C difference) and more snowfall, but lower wind speeds. Also, the Pre-boreal climate was wetter than the present and Younger Dryas climates. The main driving factors were the low temperatures of the partly sea-ice covered N Atlantic Ocean and the insolation that was very different from today, with more incoming solar radiation during summer (+30W/m2) and less during winter (-10W/m2).The presented detailed results could be valuable for interpreting palaeo-environmental records and for modelling studies on sedimentological processes during the Late Quaternary.

We describe a collection of borings in carbonate and xylic substrates (Gastrochaenolites ispp., Teredolites longissimus Kelly & Bromley), some of them containing their producers, from the Maastricht and Houthem formations (late Maastrichtian and early Danian) in the type area of the Maastrichtian Stage, but mainly from the ENCI-HeidelbergCement Group quarry, St. Pietersberg (southern Limburg, the Netherlands). Included are specimens of Gastrochaenolites dijugus Kelly & Bromley, showing different modes of formation of the figure-of-eight aperture, either as part of the lining, incorporating the substrate or both. Gastrochaenolites lapidicus Kelly & Bromley was produced by the gastrochaenid bivalve Gastrochaena, whereas G. orbicularis Kelly & Bromley is the trace of Jouannetia supracretacea (De Ryckholt). Bioglyph-like infills of G. orbicularis and G. torpedo Kelly & Bromley rather represent external moulds of the producing bivalves; they are termed pseudobioglyphs herein. Teredolites longissimus is preserved as clusters of in situ, parallel to sub-parallel tubes, although the woody substrate has decayed, and disarticulated fragments of calcareous tubes have been released from rotten wood. The latter include some specimens filled by flint and show good three-dimensional preservation. Some notes on the taxonomy of the producing bivalve taxa are added.

Clay is a common lithology in the Dutch shallow subsurface. It is used in earth constructions such as dikes, and as raw material for the fabrication of bricks, roof tiles etc. We present a new national assessment of Dutch clay resources, as part of a project that provides mineral-occurrence information for land-use planning purposes. The assessment is based on a 3D geological model, which consists of voxel cells with lithological composition as primary attribute, and has been obtained by interpolating data of more than 380,000 digital borehole descriptions. The occurrence of shell material and the extent to which clay is peaty were used as quality attributes, enabling us to tentatively distinguish between clay that is potentially suitable as ceramic material, and clay that is not.

As clay is extracted using dry (i.e. non-dredging) techniques, the model space has been dimensioned to fully encompass the unsaturated zone. A high-resolution model (with voxel cells of 250 · 250 · 0.2 m), based mainly on abundant, good-quality hand drillings, was constructed down to 3 m below the surface. This depth range suffices for clay-resource assessments in the lowlands, which have relatively high groundwater levels. Cells from a lower-resolution model (250 · 250 · 1 m, based on fewer data) were added to reach appropriate depths in upland areas.

We arrive at about 42.1 km3 of clay occurring in the model space (land areas only). Clay occurs mainly in the coastal domain and below the Rhine and Meuse river plains. Geological exploitability has been assessed within the unsaturated zone, taking overburden and intercalations with non-clay materials (especially peat) into account. The resulting exploitable stock is 12.3 to 18.0 (± 2.0) km3; an estimate in which the main source of uncertainty is presented by a lack of proper groundwater-table data. This amount equates to roughly 6000 annual consumption equivalents. Even when considering that the larger part of the clays is unsuitable for firing, and about one quarter is situated below built-up lands or nature preserves, clay is not a scarce resource in the Netherlands and supplies should present no problem in the near future.

The Broad Fourteens Basin is a NW-SE trending Mesozoic structural element that was affected by inversion movements during the Late Cretaceous (Subhercynian Phase) and Early Tertiary (Laramide Phase). Since the overlying Tertiary section of this area is relatively little studied, a multi-disciplinary investigation was initiated using both seismic and well data. The present study is the first phase of that project and deals exclusively with the stratigraphical framework and sedimentary development based on well logs from approximately forty wells.

The Tertiary sedimentary section in this area (maximum thickness up to approximately 800 m) consists of siliciclastic rocks that generally correlate well with the established lithostratigraphical framework of the Netherlands. However, the highly variable thickness of these lithological units, illustrated by isopach maps for all units, reflect the intricate pattern of sea level movements, differential vertical movements and the ensuing erosion, that took place in this tectonically active area.

Well P06-02, one of the most complete sections in the center of the area, was selected for detailed biostratigraphical analysis to support further stratigraphical subdivision and correlation. This yielded information on both the distribution pattern of various lithological units and the influence of large, partly global, events during basin development. It is concluded that application of detailed sequence stratigraphy in the study area is very problematic and only 2nd and some 3rd order cycles could be recognized.

The Holocene sea-level rise has led to significant changes in present-day coastal zones through multifold retrogradational and slightly progradational displacements of the mainland coastline. During the course of this postglacial transgression, sediments characteristic of coastal environments accumulated first in palaeovalleys of the pre-Holocene landscape and later on the subsequently developed coastal plain. Based on a compilation of sedimentological, lithological and litho-chronostratigraphical data of more than 1200 sediment cores, we generated four palaeogeographic maps of the coastal zone of the central Wadden Sea to document with a high spatial resolution the landscape changes during characteristic phases of the Holocene sea-level rise, i.e. the periods 8600–6500 cal BP, 6500–2700 cal BP, 2700–1500 cal BP and 1500–1000 cal BP. Along three cross-sections, representing different hydrodynamic conditions and exposure, we exemplify how the Holocene landscape development and sedimentary facies types are controlled by the local palaeorelief, sea-level changes, sediment supply, accommodation space, the morphodynamic impact of channel shifts, and their erosion base. This leads to a better understanding of main factors controlling the local depositional processes of the coastal landscape along the central Wadden Sea during the Holocene transgression.

Until recently, mosasaur remains from the Izumi Group (Upper Cretaceous) in southwest Japan comprised only scattered finds; now a richer material is available. From the upper Campanian Hiketa Formation in Kagawa Prefecture, Kourisodon sp. has just been recorded, on the basis of portions of skull and mandible which has small and laterally compressed teeth. A few teeth of the same or similar type have previously been described from the Maastrichtian Mutsuo Formation in Osaka Prefecture. A report of Mosasaurus sp. A, which resembles M. missouriensis and M. dekayi, is based on some cranial and mandible remains, inclusive of numerous teeth and a few well-preserved cervical and two incomplete dorsal vertebrae, from the Maastrichtian Mutsuo Formation in Osaka Prefecture. A slender tooth of Mosasaurus sp. from the Mutsuo Formation has since been reassigned to Platecarpus (Plioplatecarpinae); yet, this may indeed by a species of Mosasaurus, here listed as Mosasaurus sp. B. To date, smaller specimens of mosasaurids have been shown to be abundant in the Izumi Group, which suggests two possible explanations. Either most of these represent juveniles, or smaller-sized, Kourisodon-like animals flourished here. Finds of Kourisodon sp. from the upper Campanian Hiketa Formation and the Maastrichtian Mutsuo Formation suggests the second explanation is the more likely one.

Following a time of expansion of the oil industry, the period 1987-2012 and especially the second half of it reflects a diversification of exploration activities in the Netherlands. In addition to the ongoing discovery of classical hydrocarbon reservoirs, successful attempts have been made to explore deep geothermal energy. Shale gas and Coal Bed Methane received interest in the Netherlands too but so far no wells have been drilled in order to test the potential. Storage of gas and liquids has been introduced and salt mining more or less continued without many changes. In terms of drilling activity, the last 25 years show a decreasing trend and the discovered volumes are smaller. Testing of new play concepts was either successful (shallow gas) or not (Dinantian) and sometimes an unexpected discovery was made (Triassic Fat Sands). New techniques proved older fields to be exploitable again, e.g. redevelopment of the Schoonebeek Field. Therefore, despite a decline in number of wells drilled and reserves added, the diversification of use of the subsurface will guarantee ongoing exploration.