bluuebunny/crossref_metadata_2025 huggingface dataset:
A sporomorph ecogroup model for the Northwest European Jurassic - Lower Cretaceous II : Application to an exploration well from the Dutch North Sea
Authors: Abbink O.A. , Van Konijnenburg-Van Cittert J.H.A. , Van der Zwan C.J. , Visscher H.
Published: April 2016

Jurassic shallow marine to non-marine depositional sequences are among the most important economic targets in the North Sea. Detailed, ‘high resolution’ stratigraphy of these sequences has become a necessity in both predictive geological exploration models as well as in production reservoir models. In these paralic sequences, palynomorphs are the most abundant (micro) fossil group. Palynology is increasingly challenged to improve the biostratigraphic control, and to support the sequence stratigraphical framework. Based on a recently developed, conceptual Sporomorph EcoGroup model, the quantitative distribution patterns of terrestrial palynomorphs are grouped in six Sporomorph EcoGroups (SEGs), viz. Upland, Lowland, River, Pioneer, Coastal, and Tidally-influenced SEG. Application of the SEG model to data from a marginal marine, uppermost Callovian - Middle Oxfordian section of NAM well F17-4 from the southern part of the Central North Sea Graben allows the recognition of sea-level fluctuations and climate changes. A marked palaeoclimatic shift occurred in the earliest Middle Oxfordian. The relatively cool-subtropical, humid climate changed into a warmer, subtropical-tropical, drier climate. The sea-level reconstructions based on the SEG model are validated against a latest Callovian - Earliest Oxfordian depositional sequence.
New subsurface temperature maps for the Tertiary Lower Rhine Basin and the adjacent Variscan Basement - Germany, The Netherlands, Belgium
Authors: Karg H. , Bücker C. , Schellschmidt R.
Published: April 2016

The regional subsurface temperature field at the transition between the Palaeozoic Variscan Basement and the Cenozoic Lower Rhine Basin in Dutch, German and Belgium territories was mapped up to a depth of 1000 m. Temperature data from 66 wells and 11 coal mine subcrops were available. In 46 wells, temperature logs, covering a cumulative depth interval of 6600 m, were measured for this study.
Reservoir characterisation using process-response simulations: the Lower Cretaceous Rijn Field, West Netherlands Basin
Authors: Alberts L.J.H. , Geel C.R. , Klasen J.J.
Published: April 2016

Petroleum geologists always need to deal with large gaps in data resolution and coverage during reservoir characterisation. Seismic data show only large geological structures, whereas small-scale structures and reservoir properties can be observed only at well locations. In the area between wells, these properties are often estimated by means of geostatistics. Numerical simulation of sedimentary processes offers an alternative method to predict these properties and can improve the understanding of the controls on reservoir heterogeneity. Although this kind of modelling is widely used on basin scale in exploration geology, its application on field scale in production geology is virtually non-existent. We have assessed whether the recent developments in numerical modelling can also aid petroleum geologists in the interpretation of the reservoir geology.

Seismic data, well data and a process-response model for coastal environments were used to characterise the Lower Cretaceous oil-bearing Rijn Field. Interpretation of seismic and well data led to a definition of the structural setting and the depositional model of the Rijn Member in the area. From the sedimentological interpretation the sea-level history could be estimated, which is the one of the most important input parameters for the process-response model.

Application of the process-response simulator to the Rijn Field resulted in approval of the depositional model. The output was presented in a 2-dimensional north-south profile, which corresponds very well to the well logs along this section. The results demonstrate that numerical simulations of geological processes can be very useful as a tool to explore many likely geological scenarios. While it cannot be used to supply a unique solution in many cases, it forms a helpful guide during reservoir characterisation to find an optimal scenario of the controls on deposition of the Rijn Member, which contributes to the understanding of the inter-well reservoir heterogeneity.
Restoration of former wetlands in the Netherlands; effect on the balance between CO2 sink and CH4 source
Authors: van den Bos R.
Published: April 2016

Drained coastal peatlands are a source of greenhouse gas (GHG) through abundant CO2 release caused by aerobic peat degradation. Published rates of CO2 fixation and CH4 release for natural peatlands suggest that areas of peat formation are a (small) net source of GHG emission because the radiative effect of emitted CH4 exceeds the CO2 uptake by the vegetation. It is shown here that wetland restoration of reclaimed peat areas in the western Netherlands leads to a reduction of GHG emission because the expected increase in anaerobically generated CH4 release is much smaller than the decrease in aerobically produced CO2.
Redeposited chalk hydrocarbon reservoirs of the North Sea caused by the Chicxulub K-T bolide impact
Authors: Rider M. , Kroon D.
Published: April 2016

A widespread, slumped, redeposited, uppermost Cretaceous chalk interval, up to 60m thick, immediately below the Cretaceous-Tertiary (K-T) boundary, recognised in oil company boreholes across the central North Sea and a major hydrocarbon reservoir, we re-interpret as the result of a single, catastrophic event caused by secondary effects related to the bolide impact at Chicxulub. A thin, dark clay bed immediately above the redeposited chalks, we suggest correlates to the outcropping, Iridium rich, Danish ‘Fish Clay’, rapidly deposited after the impact. Physical effects on sea-floor sediments, caused by the K-T bolide impact, have not previously been interpreted in the North Sea.
Stratigraphic architecture of the Upper Cretaceous and Cenozoic along the
southern border of the North Sea Basin in Belgium
Authors: Vandenberghe N. , Van Simaeys S. , Steurbaut E. , Jagt J.W.M. , Felder P.J.
Published: April 2016

The Late Cretaceous and Cenozoic sedimentary record in the Campine Basin
along the southern border of the North Sea Basin is analysed in terms of
sequence stratigraphy. All available biostratigraphic, and in some cases,
magnetostratigraphic data are used to constrain the sequence
chronostratigraphy. The relative geographic extent of the strata is used as
an indication of the relative sea level. Tectonic and eustatic components
could be distinguished in several cases using regional geological
information. Generally, sequences consist of transgressive and highstand
systems tracts only and have flat, abrasion-type lower boundaries. Lowstand
deposits are only identified as infill of erosional space, which generally
implies marked tectonic uplift. Several eustatic and tectonic events can be
correlated with similar events known elsewhere in the North Sea Basin. The
time intervals spanned by the different sequences vary considerably,
pointing out different control mechanisms.
Stable oxygen isotope record of the Eocene-Oligocene transition in the
southern North Sea Basin: positioning the Oi-1 event
Authors: De Man E. , Ivany L. , Vandenberghe N.
Published: April 2016

Preliminary stable oxygen isotope data are presented from the southern
North Sea Basin successions, ranging from the Lutetian to Rupelian. Analyses
were performed on fish otoliths, nuculid bivalves and benthic foraminifera
and are presented as bulk δ18O values relative to a
well established regional sequence stratigraphic framework. The most
significant positive shift in δ18O values clearly falls
at the top of the regionally recognised Bassevelde 3 sequence, which base
corresponds to the Eocene-Oligocene GSSP boundary. The here documented
δ18O shift is closely associated with the base of
the traditional Rupelian unit-stratotype and is tentatively correlated to
the globally recognised Oi-1 event.
Late Oligocene Warming Event in the southern North Sea Basin: benthic foraminifera as paleotemperature proxies
Authors: De Man E. , Van Simaeys S.
Published: April 2016

The investigation of foraminiferal assemblages from a series of Oligocene borehole sections allowed paleoenvironment and paleoclimate reconstructions for the Rupelian and Chattian (Lower and Upper Oligocene) Stages in their type region, the southern North Sea Basin. A striking feature coinciding with the Rupelian-Chattian (R-C) unconformity is the major change in paleotemperature and paleobathymetry. The shallow marine to restricted marine subtropical fauna at the base of the Chattian is in strong contrast with the deeper marine and cooler upper Rupelian assemblages. This study suggests that the early Chattian transgression is genetically related to a widespread major warming pulse, known as the Late Oligocene Warming Event.
A new Ordovician astylospongiid sponge (Porifera) as an erratic from Baltica
Authors: Rhebergen F.
Published: April 2016

Until now hemispherical astylospongiid sponges were invariably referred to as Caryospongia juglans var. basiplana Rauff. Renewed investigations have now shown that part of the material should be assigned to a new genus and species, Tympanospongia vankempeni, which is characterised by a system of very irregular canals. These flat-based sponges originate from the Baltic region and occur in two assemblages of silicified Late Ordovician sponges known exclusively as erratics from The Netherlands and northern Germany. These fossils were transported by the River Eridanos, a former drainage system from the Baltic region that filled the North European Basin during the Miocene to Early Pleistocene. Specimens of Tympanospongia vankempeni gen. et sp. nov. also occur in the Upper Pleistocene of Gotland, Sweden. The new sponge described herein principally differs from other genera of the Astylospongiidae found frequently in the erratic sponge assemblages by its irregular system of apochetes which ramify and anastomose commonly.
A southern North Sea Miocene dinoflagellate cyst zonation
Authors: Munsterman D.K. , Brinkhuis H.
Published: April 2016

An integrated stratigraphical analysis emphasizing organic-walled dinoflagellate cyst (dinocyst) distribution has been carried out on multiple boreholes penetrating the Miocene in the subsurface of the Netherlands (southern North Sea Basin). The bulk of the investigated successions is attributed to the Breda Formation, a regional lithostatigraphical unit most complete in the south-eastern part of the Netherlands. In concert with a first regional integrated bio (chrono) sequence-stratigraphical framework, fourteen informal dinocyst zones for the southern North Sea Miocene (SNSM), and three subzones are proposed for the Breda Formation. By also integrating (chrono)stratigraphic information from Mediterranean and North Atlantic dinocyst studies a first ever detailed age-model is here proposed for the Miocene in the subsurface of the Netherlands.
A sporomorph ecogroup model for the Northwest European Jurassic - Lower Cretaceousi: concepts and framework
Authors: Abbink O.A. , Van Konijnenburg-Van Cittert J.H.A. , Visscher H.
Published: April 2016

Based on recent vegetation distribution and an integration of macropalaeobotanical and palynological information, a palaeocommunity model is explored that may permit detailed interpretations of quantitative sporomorph distribution patterns in the Jurassic and Early Cretaceous of NW-Europe in terms of changes in palaeoenvironment (sea-level, climate). The conceptual model is based on the recognition of Sporomorph Ecogroups (SEGs) that reflect broad co-existing plant communities, viz. upland, lowland, river, pioneer, coastal, and tidally-influenced SEGs. In successive palynological assemblages, shifts in the relative abundance of SEGs are thought to be indicators of sea-level changes. Climatic changes may be recognised through significant shifts within the quantitative composition of individual SEGs.
Marine Miocene deposits in the Maaseik well 49W/220 in eastern Belgium: biostratigraphy by means of various microfossil groups.
Authors: Hooyberghs H. , Wouters K. , Spiegler D.
Published: April 2016

A micropalaeontological analysis (foraminifera, ostracoda andbolboforma)has been undertaken for the interval between 299.7 and 201.5m of the Maaseik borehole. This interval includes marine glauconitic sands, which are generally not or not strongly decalcified. Independent from each other, the observed taxa of the different microfossil groups indicate a Late (range down to Middle) Miocene age for the interval. On the base of the biozonations of the various microfossil groups, some correlations can be presented with Late Miocene deposits of other areas in Belgium (Antwerp and Campine area), and of other places in NW Europe.
Faults in the Asquempont area, southern Brabant Massif, Belgium
Authors: Debacker T.N. , Herbosch A. , Verbiers J. , Sintubin M.
Published: April 2016

The literature suggests that the Asquempont fault, a supposedly important reverse fault forming the limit between the Lower to lower Middle Cambrian and the Ordovician in the Sennette valley, is poorly understood. Nevertheless, this fault is commonly equated with a pronounced NW-SE-trending aeromagnetic lineament, the Asquempont lineament, and both the geometry of the Asquempont lineament and the supposed reverse movement of the Asquempont fault are used to develop large-scale tectonic models of the Brabant Massif. New outcrop observations in the Asquempont area, the “type locality” of the Asquempont fault, in combination with outcrop and borehole data from surrounding areas, show that the Asquempont fault is not an important reverse fault, but instead represents a pre-cleavage, low-angle extensional detachment. This detachment formed between the Caradoc and the timing of folding and cleavage development and is not related to the aeromagnetic Asquempont lineament. The Asquempont area also contains several relatively important, steep, post-cleavage normal faults. Apparently, these occur in a WNW-ESE-trending zone between Asquempont and Fauquez, extending westward over Quenast towards Bierghes. This zone coincides with the eastern part of the WNW-ESE-trending Nieuwpoort-Asquempont fault zone, for which, on the basis of indirect observations, previously a strike-slip movement has been proposed. Our outcrop observations question this presumed strike-slip movement. The Asquempont fault may be related to the progressive unroofing of the core of the Brabant Massif from the Silurian onwards. Possibly, other low-angle extensional detachments similar to the Asquempont fault occur in other parts of the massif. Possible candidates are the paraconformity-like contacts depicted on the most recent geological map of the Brabant Massif.
A new record of Clidastes (Squamata, Mosasauridae) from the Upper Campanian of the Münster Basin (NW Germany)
Authors: Diedrich C. , Mulder E.W.A.
Published: April 2016

From Upper Campanian turbiditic marls at Beckum in the Münster Basin (NW Germany) the anterior portion of a mosasaurid premaxilla with abutting fragments of the left and right maxilla is described and referred to the genus Clidastes. It shows the process of tooth replacement very well. This taxon is recorded for the first time from Germany. Clidastes co-existed in central Europe with other mosasaurids such as representatives of the genus Leiodon and Mosasauridae indet.
The Pleistocene College Farm Silty Clay at Great Blakenham, Suffolk, England – additional information on the course of the early River Thames
Authors: Moorlock B.S.P. , Riding J.B. , Hamblin R.J.O. , Allen P. , Rose J.
Published: April 2016

The Pleistocene College Farm Silty Clay Member of the Creeting Formation at Great Blakenham, Suffolk, south-east England is shown to contain indigenous and recycled dinoflagellate cysts and other derived palynomorphs. The indigenous dinoflagellate cysts indicate a marine influence during deposition of the clay, whilst the other palynomorphs demonstrate derivation of sediment from a wide catchment of Carboniferous, Jurassic and Cretaceous bedrocks. It is argued, by comparison with palynological data from the Chillesford Clay Member of the Norwich Crag Formation some 25km to the east, that these sediments were eroded from western, south-central and south-eastern Britain, and transported by the early River Thames to its estuary, where they were redeposited at the western margin of the Crag Basin, during the Early Pleistocene Tiglian TC3 Substage. This interpretation refines earlier research which concluded the College Farm Silty Clay was deposited in a predominantly freshwater environment, such as a lagoon, without any direct access to the sea or major river.
Internal structure and development of an aeolian river dune in The Netherlands, using 3-D interpretation of ground-penetrating radar data
Authors: Van Dam R.L.
Published: April 2016

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.
Soil formation in Late Glacial Meuse sediments related to the Peel Boundary Fault activity
Authors: Miedema R. , Jongmans T.
Published: April 2016

Micromorphological studies relating the soil formation history (processes and timing) to activity events of the Peel Boundary Fault (PBF) showed rotation features (circular distribution pattern of sand grains) in mechanically displaced rounded fragments of Bt bands. These features are interpreted as being caused by ‘mudflow’ during active faulting event (PBF event F2). The micromorphological interpretation of Late Weichselian soil formation (clay illuviation, degradation features and offsetting of Bt bands) agrees with the hypothesized 3 PBF periods of fault activity events (Fl, F2 and F3).
Thermal gradients in Europe during the last glacial-interglacial transition
Authors: Renssen H. , Isarin R.F.B. , Vandenberghe J.
Published: April 2016

Temperature profiles along east-west and north-south transects in Europe are presented for four time-slices covering the two most prominent warming phases of the last glacial-interglacial transition: Late Pleniglacial (LP), early Bøiling (BL), Younger Dryas (YD), and Preboreal (PB). These temperature profiles are based on two methods: 1) simulation experiments with an atmospheric general circulation model, 2) reconstructions based on terrestrial geological and palaeoecological data. The profiles have The Netherlands as intersection point (52°N, 5°E). During the cold phases (LP and YD), the simulated and reconstructed temperature gradients are very steep in a north-south direction, ranging in January from -25°C in northern Europe (56–60°N) to at least 5°C near the Mediterranean, and in July from 0°C to 20°C. The east-west profiles along 52°N for LP and YD show that temperatures in Eastern Europe were similar to the Atlantic coast (i.e. between ‒15°C and ‒25°C). During the warm phases (BL and PB), the temperature regimes resembled present-day thermal conditions, although steeper north-south and east-west temperature gradients were present during BL and PB. The model simulations suggest that continental Europe was a few degrees warmer during PB and BL than today in July under influence of the relatively high summer insolation. Considering the change of climate through time, the profiles show that in The Netherlands the warming during the two transitions (LP-BL, YD-PB) was relatively small compared to regions to the West and North, whereas in Eastern and Southern Europe the temperature increase is even smaller. This reflects the dominant influence of latitudinal movements of the North Atlantic polar front and associated sea-ice margin.
Climatic and environmental events over the Last Termination, as recorded in The Netherlands: a review
Authors: Hoek W.Z. , Bohncke S.J.P. ,   The Netherlands Centre for Geo-ecological Research (ICG)
Published: April 2016

The Last Termination, or Weichselian Lateglacial (ca 15–10 ka cal. BP), is a time period with rapid changes in climate and environment. The oxygen-isotope records of the Greenland ice-cores are regarded as the most complete climate proxy for the North Atlantic region. In The Netherlands several other proxies have been investigated and dated in great detail over the last few decades. However, changes registered in the different records are not by definition causally related to climate changes. Comparison of the different records on a common time-scale permits evaluation of the interrelationships and correlations to the Greenland ice-cores. Some events are the result of the complex interplay of different environmental variables and have no causal relationship with climate changes at all. By comparing the different records on a common time-scale and examining spatial patterns, the links between the proxies become evident.
Relative water-level rise in the Flevo lagoon (The Netherlands), 5300-2000 cal. yr BC: an evaluation of new and existing basal peat time-depth data
Authors: Makaske B. , Van Smeerdijk D.G. , Peeters H. , Mulder J.R. , Spek T.
Published: April 2016

The rise of Holocene (ground)water level as a function of relative sea-level rise has been extensively investigated in the western Netherlands, whereas few studies focused on the Flevo lagoon in the central Netherlands. In this study, all available 14C dates from the base of basal peat overlying the top of compaction-free Pleistocene sand in the former Flevo lagoon were evaluated in order to reconstruct water-level rise for the period 5300-2000 cal. yr BC. The present basal peat 14C data set from Flevoland consists of two subsets: (1) the largely new Almere data (41 dates) representing the southern part of the former Flevo lagoon, with 26 dates especially carried out for this study, and (2) the existing Schokland data (21 dates) representing the eastern part of the lagoon. The Schokland area is located about 50 km from the Almere area. The quality of all basal peat time-depth data was palaeo-ecologically and geologically evaluated, all 14C dates were calibrated to the same standards, and error margins of age and altitude determination were estimated. After plotting the data as error boxes in time-depth graphs, lower limit curves for water-level rise were constructed for both data sets. Comparison with the mean sea-level curve for The Netherlands (Van de Plassche, 1982) suggests that water-level rise in the Almere area between 5300 and 2000 cal. yr BC corresponded closely to the rise in mean sea level. The same holds for the Schokland area for the period 5000-4200 cal. yr BC. For the period 4200-2000 cal. yr BC, however, the Schokland data suggest water-level rise to have been slower than mean sea-level rise, leading to local water levels apparently below mean sea level, which is virtually impossible. Hypothetical explanations for this discrepancy include: errors and uncertainties in mean sea-level and local water-level reconstruction, basin subsidence and temporal differences in intra-coastal tidal damping. The presently available data are inconclusive at this point and Holocene water-level rise in the Flevo lagoon awaits further investigations.
The origin of brackish and saline groundwater in the coastal area of the Netherlands
Authors: Post V.E.A. , Van der Plicht H. , Meijer H.A.J.
Published: April 2016

An explanation is presented for the origin of brackish to saline groundwater in the coastal area of the Netherlands based on geological, chemical (chlorinity), isotopic and geophysical data. A critical review of all possible salinization mechanisms shows that the origin of the brackish water is related to former transgressions. Both the vertical salinity distribution and the carbon-14 activity of the groundwater indicate that connate sea water from the Pliocene to Early Pleistocene is not the source of the brackish to saline waters in the overlying Pleistocene fluvial aquifers. Instead, it derives from Holocene transgressions. The salinization mechanism is discussed in relation to the paleogeographical development during the Holocene and the occurrence of low-permeability strata. Finally, freshening of the aquifers following retreat of the sea is briefly considered.
The echinoid genus Echinogalerus in the Maastrichtian type area
Authors: Van der Ham R. , Van Birgelen M.
Published: April 2016

The Late Cretaceous echinoid genus Echinogalerus König, 1825 is remarkably diverse in the Maastrichtian type area (SE Netherlands and adjacent parts of NE Belgium and western Germany). So far, five species have been recognised, namely E. belgicus (Lambert, 1898), E. minutus (Smiser, 1935), E. muelleri (Schlüter, 1902), E. pusillus Lambert, 1911 and E. vetschauensis (Schlüter, 1902), which occur from the base of the Lower Maastrichtian (E. belgicus, E. pusillus, E. muelleri) up to the K/T boundary (E. minutus). Echinogalerus muelleri, which has the longest stratigraphical range, is the most diverse, while E. pusillus is the smallest echinoid in the area, reaching maximum lengths of 4.5 mm. Comparisons with other species of Echinogalerus described in the literature have now led to the recognition of three tentative infrageneric alliances. It is argued that the ordinal position of Echinogalerus (Holectypoida or Cassiduloida) cannot be evaluated as long as many species are still insufficiently known and two genera, from the Maastrichtian of northern Germany and Denmark, intermediate between the two orders, remain undescribed.
The stratigraphic range of the index ammonitePachydiscus neubergicus(von Hauer, 1858) in the type area of the Maastrichtian Stage
Authors: Jagt J.W.M. , Felder W.M.
Published: April 2016

In the extended type area of the Maastrichtian Stage (southern Limburg, the Netherlands; provinces of Limburg and Liège, Belgium; Aachen area, Germany), the pachydiscidPachydiscus (P.) neubergicus(von Hauer, 1858) ranks amongst the rarer species of Campanian-Maastrichtian ammonites. To date, just four specimens are known, which showP. (P.) neubergicusin this area to have been confined to the Vijlen Member (Intervals 0–6, Gulpen Formation). This would correspond to the basalsumensisZone to the lowercimbricaZone, ortegulatus/juniorZone, depending on placement of the Lower/Upper Maastrichtian boundary. Material available has been collected in recent years at the CBR-Lixhe (Liège, Belgium) and ENCI-Maastricht bv (Maastricht) quarries as well as from outcrop 62D-26 at Vijlenerbosch (Vijlen, the Netherlands). Records ofP. (P.) neubergicus, the proposed index for the base of the Maastrichtian Stage, from elsewhere in Europe (northern Spain, SW France, Austria, Denmark, Bulgaria), suggest it to have been fairly long-ranging and show local first occurrences to have been diachronous.
On the alleged presence of Halisaurus (Squamata, Mosasauridae) in the latest Cretaceous of the Maastrichtian type area
Authors: Mulder E.W.A.
Published: April 2016

The presence of Halisaurus (Squamata, Mosasauridae) in the uppermost Cretaceous of the Maastrichtian type area, suggested by Lingham-Soliar (1996) on the strength of two partial vertebrae, is questioned. The anatomy of these elements suggests that they pertain not to Halisaurus, but more probably to Plioplatecarpus marshi Dollo, 1882.
Correlation of calcareous nannofossil zones to the local first occurrence ofPachydiscus neubergicus(von Hauer, 1858) (Ammonoidea) in European Upper Cretaceous sections
Authors: Wagreich M. , Küchler T. , Summesberger H.
Published: April 2016

The first occurrence (FO) of the ammonitePachydiscus 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 ofP. neubergicuswithin standard nannofossil zone CC23a (UC16), below the LO ofBroinsonia parca constricta. Other sections such as the type locality Neuberg (Austria), Nagoriani (the Ukraine) and Bjala (Bulgaria) indicate considerable diachroneity of local FOs and showP. neubergicusto range up to nannofossil zone CC25b/c (UC20; Late Maastrichtian).
First record of Pachydiscus noetlingi Kennedy, 1999 (Ammonoidea) from the Maastrichtian type area (the Netherlands)
Authors: Jagt J.W.M. , Kennedy W.J.
Published: April 2016

Two specimens of a pachydiscid ammonite, a fragmentary silicified phragmocone from the Kunrade Limestone facies at Kunrade (Schunck), and a partial external mould preserved in flint from the Nekum Member (both Maastricht Formation, Belemnitella junior Zone of authors) at the former Blom quarry (Berg en Terblijt), are identified as Pachydiscus (P.) noetlingi Kennedy, 1999, a species previously known only from the Upper Maastrichtian of Baluchistan (Pakistan). This new record underscores the proposal of incursions of Tethyan biota into the type area of the Maastrichtian Stage, previously documented for other groups, including echinoderms and bivalves, as well.
Durophagous Mosasauridae (Squamata) from the Upper Cretaceous phosphates of Morocco, with description of a new species of Globidens
Authors: Bardet N. , Suberbiola X. Pereda , Iarochène M. , Amalik M. , Bouya B.
Published: April 2016

Three durophagous mosasaur species are represented by isolated teeth in the Upper Cretaceous (Maastrichtian) phosphatic beds of Morocco. Globidens phosphaticus nov. sp. is characterised mainly by a strong heterodonty, with mid-posterior teeth being bulbous, irregularly oval in crosssection, and having an inflated posterior surface, a large eccentric located and recurved apical nubbin, vertical sulci on medial and lateral faces, no carinae and an enamel surface covered by anastomosing ridges. Teeth of Prognathodon currii are broad and tall, straight cones, slightly swollen at the base, and with two serrated carinae. These two taxa have been collected from all the phosphatic series (lower to upper Maastrichtian) in the Ganntour Basin (Morocco). Globidens phosphaticus nov. sp. is probably also represented at other Maastrichtian phosphatic sites along the southern margin of the Mediterranean Tethys. Prognathodon currii was previously known only from the Upper Cretaceous phosphates of Negev. Of the third taxon, Carinodens belgicus, only a single tooth (now lost) is known from the Oulad Abdoun Basin (Morocco); this is low, swollen, laterally compressed and bicarinate with a large apical nubbin. Previous records of this species include Europe and Brazil.
Annotated catalogue of marine squamates (Reptilia) from the Upper Cretaceous of northeastern Mexico
Authors: Buchy M.-C. , Smith K.T. , Frey E. , Stinnesbeck W. , González González A.H. , Ifrim C. , López-Oliva J.G. , Porras-Muzquiz H.
Published: April 2016

Recent work in the Upper Cretaceous of northeastern Mexico has produced a diversity of vertebrate remains. For specimens referable to Squamata, both old and new, an annotated catalogue is here provided, wherein are summarised the geological context and morphological features of each specimen. All specimens appear to represent marine squamates, including an aigialosaur-like reptile preserving integumentary structures, several vertebrae possibly representing mosasauroids, the first Mexican mosasaur known from significant cranial material, an isolated mosasaur mandibular fragment, and the holotype of Amphekepubis johnsoni (considered to belong to Mosasaurus). These discoveries are auspicious and should deepen our understanding of palaeobiogeographic and evolutionary patterns
Of German princes and North American rivers: Harlan’s lost mosasaur snout rediscovered
Authors: Caldwell M.W. , Bell G.L.
Published: April 2016

The lost snout of Richard Harlan’s specimen of Mosasaurus missouriensis has been rediscovered in the vertebrate palaeontology collections of the Muséum national d’Histoire Naturelle (MNHN) in Paris, France. The specimen (MNHN 9587) bears the handwritten description, ‘Amérique du Nord. Par M. Harlan.’, which translated reads, ‘North America. By/From Mr. Harlan’. Accession information indicates the specimen was a gift to the museum prior to 1860 and was likely gifted from Harlan’s estate after his death. We examine the available history of the collection of the specimen present a description of the rediscovered snout, and demonstrate conclusively the conspecificity of M. maximiliani Goldfuss, 1845 and M. missouriensis (Harlan, 1834a) by providing a revised diagnosis of the taxon.
Remains of Clidastes Cope, 1868, an unexpected mosasaur in the upper Campanian of NW Germany
Authors: Caldwell M.W. , Diedrich C.G.
Published: April 2016

The mosasaurine Clidastes sp. is recognised from cranial and post-cranial remains collected at four localities in NW Germany. Cranial material was found in pelagic turbiditic marls which crop out near the village of Beckum, while post-cranial skeletal elements were collected from sandy limestones exposed near the villages of Schöppingen, Coesfeld and Billerbeck. In stratigraphic order, the units producing these specimens of Clidastes are the Coesfeld, Baumberge and Beckum formations of late Campanian (Late Cretaceous) age. The cranial material comprises the anterior part of a skull and a single isolated tooth, while post-cranial bones comprise a few isolated vertebrae and a partial skeleton including forelimb bones and an articulated vertebral column. Clidastes is known to date from the western North Sea Basin (England), southern Sweden, as well as from North America (Western Interior Seaway and Gulf Coast).
Recent mosasaur discoveries from New Jersey and Delaware, USA: stratigraphy, taphonomy and implications for mosasaur extinction
Authors: Gallagher W.B.
Published: April 2016

The Upper Cretaceous deposits of New Jersey and Delaware produced the first mosasaur specimens collected in North America. Recent recovery of mosasaur specimens from streambank exposures and new excavation sites has increased our knowledge of the stratigraphic distribution of these animals in the northern Atlantic coastal plain. Reassessment of the source and age of mosasaur specimens from the Big Brook site and other localities in Monmouth County (NJ) has greatly increased the number of known Campanian mosasaur specimens from this region. Two main taphonomic occurrence modes are noted: 1 - single, worn and broken bones and isolated teeth in mixed faunal deposits probably accumulated due to current action in nearshore environments; 2 - partial skeletons, skulls and single bones in deeper-water settings were the aftermath of biological modification of carcasses and deadfalls. The mosasaurs of the New Egypt Formation represent some of the last (i.e., stratigraphically highest) mosasaur fossils in North America. Mosasaur extinction was due to the collapse of the rich Late Cretaceous marine food web at the K/T boundary. Subsequently in the early Paleocene, with the disappearance of the mosasaurs, crocodilians became the apical predators of the marine environment in this area.
Danish mosasaurs
Authors: Lindgren J. , Jagt J.W.M.
Published: April 2016

Presented are the first formal descriptions of mosasaur remains of Maastrichtian age from the Danish mainland (Jylland, Sjælland); just two taxa are recognised, viz.Mosasauruscf.hoffmanniandPlioplatecarpussp. Recent finds include an association of skeletal fragments, inclusive of a single marginal tooth crown, from within 10 metres or so of the K/T boundary near Holtug, Stevns Klint (Sjælland, eastern Denmark), here assigned toPlioplatecarpussp. A brief review of previous records of Danish mosasaurs is added.
Russellosaurus coheni n. gen., n. sp., a 92 million-year-old mosasaur from Texas (USA), and the definition of the parafamily Russellosaurina
Authors: Polcyn M.J. , Bell G.L.
Published: April 2016

A new mosasaur, Russellosaurus coheni, is described from the Collignoniceras woollgari Zone (lower Middle Turonian) at Cedar Hill, Dallas County, Texas. At approximately 92 Ma, it is the oldest well-preserved mosasaur skull from North America. It possesses characters diagnostic of Plioplatecarpinae but retains numerous plesiomorphies as well. Phylogenetic analysis indicates a close relationship with Yaguarasaurus columbianus, and these two, together with Tethysaurus nopcsai, form a clade that occupies a position basal to the divergence of the subfamilies Tylosaurinae and Plioplatecarpinae. Russellosaurus coheni is proposed as the nominal taxon of a new mosasaur clade, parafamily taxon novum Russellosaurina, which includes Plioplatecarpinae, Tylosaurinae, their common ancestor and all descendants. Tethysaurus retains a plesiopedal limb and girdle morphology, and along with Russellosaurus and Yaguarasaurus, cranial plesiomorphies. Dallasaurus turneri, a temporally and geographically sympatric plesiopedal mosasaur, occupies a basal position within Mosasaurinae. This phyletic arrangement confirms that marine adaptations, such as development of paddle-like limbs, occurred independently in at least two lineages of mosasaurs, once within Mosasaurinae and once within Russellosaurina.
Mosasaur remains from the Upper Cretaceous Izumi Group of southwest Japan
Authors: Tanimoto M.
Published: April 2016

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.
The alluvial architecture of the Coevorden Field (Upper Carboniferous), the Netherlands
Authors: Kombrink H. , Bridge J.S. , Stouthamer E.
Published: April 2016

A detailed reconstruction of the alluvial architecture of the Coevorden gas Field (Tubbergen Formation, Upper Carboniferous), which is located in the northeastern part of the Netherlands, is presented. This reconstruction is based on well logs, cross-sections and paleogeographic maps. Sedimentological analysis of a 93 m long core allowed to refine the interpretation of the depositional environment. Accurate width determinations are necessary to correctly correlate fluvial sandbodies and reconstruct alluvial architecture. Without using sedimentological information, sandbody width is likely to be overestimated. A method developed by Bridge and Tye (2000) was used to calculate the width of one sandstone body from cross-set thicknesses. On the basis of this calculation and the paleogeographic reconstructions, it may be stated that on average the width of the channel belts we studied in the Coevorden field does not exceed 4 km. Moreover, our paleogeographic reconstructions, which point to a northwestern direction of paleoflow, are in accordance with earlier observations from the study area. The Tubbergen Formation and time-equivalent sediments in Germany are reviewed briefly to put the Coevorden Field in a regional context. The thickness of the Tubbergen Formation is ∼450 m in our study area. In the adjacent German area, time-equivalent sedimentary sequences reach higher thicknesses. This may be attributed to tectonic movements along the Gronau Fault zone and the coming into existence of the Ems Low, of which the Coevorden Field is the westernmost part.
Ground-penetrating radar profiling on embanked floodplains
Authors: Bakker M.A.J. , Maljers D. , Weerts H.J.T.
Published: April 2016

Management of the Dutch embanked floodplains is of crucial interest in the light of a likely increase of extreme floods. One of the issues is a gradual decrease of floodwater accommodation space as a result of overbank deposition of mud and sand during floods. To address this issue, sediment deposits of an undisturbed embanked floodplain near Winssen along the river Waal were studied using ground-penetrating radar (GPR). A number of radar facies units were recognized. Boreholes were used to relate radar facies units to sedimentary facies and to determine radar velocity. The GPR groundwave is affected by differences in moisture and texture of the top layer and probably interferes with the first subsurface reflector. The architectural elements recognized in the GPR transects confirm earlier reported insights on human-influenced river behaviour. This is testified in the development of sand bars during flood regimes that are probably more widespread than previously established.
The influence of floodplain morphology and river works on spatial patterns of overbank deposition
Authors: Thonon I. , Middelkoop H. , van der Perk M.
Published: April 2016

Floodplain topography and related hydraulic patterns of overbank flow constitute a major control on the amounts and patterns of sediment deposition on floodplains. We studied the differences in sediment deposition at two scales along two river branches of the lower River Rhine in the Netherlands: the Waal and IJssel River. Human alterations like levelling and embankment construction have severely impacted the floodplains along the Waal River branch (average discharge: 1500 m3·s‒1), whereas the relatively wide floodplains along the IJssel River (average discharge: 250 m3·s‒1) still exhibit their characteristic ridge-and-swale topography and natural levees. We found that, in general, the amounts of sediment deposited sediment decreases with increasing distance to the sediment source. Clay and organic matter content generally increase with decreasing floodplain elevation. These trends are, however, far less pronounced in the Waal River floodplains than in the IJssel River floodplains. Sediment deposited on the IJssel River floodplains also contains significantly more sand than the sediment deposited on the Waal River floodplains, probably because of the absence of minor embankments along the IJssel River and its higher sinuosity. Furthermore, during inundation the individual Waal River floodplains receive more sediment per unit area than the IJssel River floodplains. At the scale of the river branch, however, the conveyance losses in the Waal River are less than in the IJssel River, because of the larger surface area of the floodplains along the IJssel River relative to its water and sediment discharge during flood events. This discrepancy stresses that both the individual floodplain sections and the total river branch should be taken into account when studying the role of overbank deposition as part of a river’s sediment budget.
On the use of flexible spillways to control the discharge ratio of the Rhine in the Netherlands: hydraulic and morphological observations
Authors: Schielen R.M.J , Jesse P. , Botwidt L.J.
Published: April 2016

Shortly after the river Rhine enters the Netherlands, it bifurcates into three branches. A predefined, fixed discharge distribution over the bifurcation points is vital, since the dikes are designed with a predefined distribution in mind. Recent observations show that the discharge distribution that is anticipated at design discharge conditions differs from the predefined one. One of the goals of the national program Room for the River is therefore to restore the discharge distribution. To control the hydraulic processes during flood events, the construction of two adaptable spillways in the direct neighbourhood of the bifurcation points is proposed as a possible solution. The spillways are capable of maintaining the proper discharge distribution. They can also act as regulators during the construction phase of the flood managements plans of the project Room for the River. Hence, the discharge ratio and thus the water levels are such that the safety-standards are not violated. The morphological consequences are most probably very small, provided that strong erosion during flood events can be prevented and the autonomous bed degradation stays within reasonable limits.