A revised Upper Cenozoic stratigraphic framework of the Dutch sector of the North Sea Basin is presented whereby offshore stratigraphic units are integrated or correlated with onshore units. The framework is based on an integrated stratigraphic approach that combines elements of lithostratigraphy, seismostratigraphy and allostratigraphy. Offshore formations are redefined in terms of seismofacies and lithofacies associations, and are differentiated on the basis of common genesis and stratigraphic position. These facies associations represent five major depositional environments, which occur in repetitive successions in the subsurface of the Netherlands: Marine, Coastal, Glacial, Fluvial, and Local Terrestrial.Five conceptual basin-wide bounding discontinuities are identified in the North Sea-Basin that span land and sea. They are represented by both seismostratigraphic and lithostratigraphic unconformities and interpreted as surfaces that formed as a result of North Sea Basin-wide changes in depositional systems. Their formation relates to sea level rise, continental-scale glaciations, and tectonic processes. The bounding discontinuities separate informal allostratigraphic groups of formations that have a grossly uniform geologic setting in common. While the allostratigraphic principles provide a view on the stratigraphy on the largest spatial and temporal scale, the genetic concept facilitates mapping on a local scale.

In order to obtain a better understanding of the infilling of the Saalian glacial basins during the Eemian, particularly following the recent research in the Amsterdam Basin (Terminal borehole), it was necessary to re-investigate the type locality of the Eemian at Amersfoort. Both published and unpublished data from various biota (diatoms, foraminifers, molluscs, ostracods, pollen) provide new information on the changing sedimentary environments during the Eemian. Although the organic and clastic sediments of the infilling represent nearly all the pollen zones, the sedimentary sequence at Amersfoort is discontinuous: four breaks at least are recognised at the type locality.The successive sedimentary environments and the breaks in the record are linked with the transgression of the Eemian sea, the topographic position at the margin of an ice-pushed ridge, and the changes in hydrodynamic conditions. Local conditions, such as a sandy sea bed, shallow water and a reduced water exchange near the North Sea margin, influenced the salinity of the basin. Rib counts of Cerastoderma edule shells indicate a higher salinity at the end of the Taxus (E4b) and the beginning of the Carpinus (E5) zones than that present in the modern North Sea. Local conditions were responsible for the higher salinity following the climate optimum.During the Abies phase (the later part of regional pollen zone E5), the sea level had already fallen. The change from eu-trophic peat growth (with Alnus and Salix) to an oligotrophic Ericaceae/Sphagnum community at the end of the Eemian resulted from the change from a marine to a fresh-water environment, probably coherent with a deterioration of the climate.

ScopePursuant to a new law that will become effective in 2015, DINO, the national Dutch subsurface database operated by the Geological Survey of the Netherlands, is to become an official government register (a 'key register' / basisregistratie). In facing the responsibilities associated with this new status, the Survey is reconsidering and redesigning its operation and in that process a new, or at least sharper picture is emerging of geological surveying in the future.These developments set the final stages of a process of modernisation that geological survey organisations all over the world are currently entangled in (Allen, 2003;Jackson, 2010). Most surveys are replacing paper archives that were built in the AbstractOver the last ten to twenty years, geological surveys all over the world have been entangled in a process of digitisation. Their paper archives, built over many decades, have largely been replaced by electronic databases. The systematic production of geological map sheets is being replaced by 3D subsurface modelling, the results of which are distributed electronically. In the Netherlands, this transition is both being accelerated and concluded by a new law that will govern management and utilisation of subsurface information. Under this law, the Geological Survey of the Netherlands has been commissioned to build a key register for the subsurface: a single national database for subsurface data and information, which Dutch government bodies are obliged to use when making policies or decisions that pertain to, or can be affected by the subsurface. This requires the Survey to rethink and redesign a substantial part of its operation: from data acquisition and interpretation to delivery. It has also helped shape our view on geological surveying in the future.The key register, which is expected to start becoming operational in 2015, will contain vast quantities of subsurface data, as well as their interpretation into 3D models. The obligatory consultation of the register will raise user expectations of the reliability of all information it contains, and requires a strong focus on confidence issues. Building the necessary systems and meeting quality requirements is our biggest challenge in the upcoming years. The next step change will be towards building 4D models, which represent not only geological conditions in space, but also processes in time such as subsidence, anthropogenic effects, and those associated with global change.Keywords: Netherlands, applied geoscience, hydrogeology, geological surveying, mapping, geomodelling, geodatabase Netherlands Journal of Geosciences -Geologie en Mijnbouw | 92 -4 | 217-241 | 2013 217 course of many decades by electronic databases; many surveys started producing electronically distributed 3D subsurface models in addition to or instead of 2D geological maps that were their primary output since their establishment. For a variety of reasons explained below, the Dutch survey is among the early adapters in both respects.In this overview paper we present the Geological S...

The Amsterdam glacial basin was a major sedimentary sink from late Saalian until late Eemian (Picea zone, E6) times. The basin’s exemplary record makes it a potential reference area for the last interglacial stage. The cored Amsterdam-Terminal borehole was drilled in 1997 to provide a record throughout the Eemian interglacial. Integrated facies analysis has resulted in a detailed reconstruction of the sedimentary history.After the Saalian ice mass had disappeared from the area, a large, deep lake had come into being, fed by the Rhine river. At the end of the glacial, the lake became smaller because it was cut off from the river-water supply, and eventually only a number of shallow pools remained in the Amsterdam basin. During the early Eemian (Betula zone, El), a seepage lake existed at the site. The lake deepened under the influence of a steadily rising sea level and finally evolved into a silled lagoon (late Quercus zone, E3). Initially, the lagoon water had fairly stable stratification, but as the sea level continued to rise the sill lost its significance, the lagoon becoming well mixed by the middle of the Corylus/Taxus zone (E4b). The phase of free exchange with the open sea ended in the early Carpinus zone (E5), when barriers developed in the sill area causing the lagoon to become stratified again. During the Late Eemian (late E5), a more dynamic system developed. The sandy barriers that had obstructed exchange with the open sea were no longer effective, and a tidally-influenced coastal lagoon formed.The Eemian sedimentary history shown in the Amsterdam-Terminal borehole is intimately connected with the sea-level history. Because the site includes both a high-resolution pollen signal and a record of sea-level change, it has potential for correlation on various scales. Palaeomagnetic results show that the sediments predate the Blake Event, which confirms that this reversal excursion is relatively young. The U/Th age of the uppermost part of the Eemian sequence is 118.2±6.3 ka.

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