bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractFloodplain 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

AbstractShortly 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.
Integrated chronostratigraphy of the Pliocene-Pleistocene interval and its relation to the regional stratigraphical stages in the southern North Sea region
Authors: Kuhlmann G. , Langereis C.G. , Munsterman D. , van Leeuwen R.-J. , Verreussel R. , Meulenkamp J.E. , Wong Th.E. 
Published: April 2016

AbstractTime-stratigraphic interpretations of Late Pliocene to Early Pleistocene sediments from onshore locations and from marginal marine settings of the North Sea Basin often refer to the subdivision of the Dutch and British ’Quaternary’ regional stratigraphic stages. Since age control for these stages and their stage boundaries are based on relative dating methods, in this study pollen, dinoflagellate cysts and foraminiferal assemblages were investigated to correlate the regional stratigraphic stages independently to the global chronostratigraphy and the paleomagnetic timescale. The data were obtained from eight boreholes located in the depocentre setting of the Late Pliocene North Sea Basin comprising a 1000 m thick sedimentary succession. The British Gedgravian and Waltonian stages, the Dutch Reuverian to Brunssumian as well as published foraminiferal zones (NSB 14, FB and the lower part of the FA2 zone) fall within the Zanclean and Piacenzian. The lower boundaries of the Pre-Ludhamian and Pretiglian stages and of the NSB 14 to 15 zones are close to the paleomagnetic Gauss-Matuyama boundary. The Pre-Ludhamian, Ludhamian, Thurnian and the Pretiglian, Tiglian A and Tiglian B stages presumably cover the marine isotope stages 103 to 95. It is proposed that the Ludhamian, Thurnian and the Tiglian A were short lasting, warm, periods during which sea level highstand facilitated sedimentary deposition at the marginal areas of the North Sea Basin. The lower boundary of the paleomagnetic Olduvai subchron is situated in the Tiglian Cl-4b stage while the TC4c stage is found within the Olduvai subchron. Foraminiferal NSB 15 and NSB 16 zone as well as the upper part of the FA2 and FA1 zone fall within the Gelasian and cover the Matuyama chron as well as the lower part of the Olduvai subchron. Comparison with formerly dated North Sea sediments shows a good agreement between foraminiferal zonations on a broader scale but significant differences in absolute ages occur. Strontium isotope values indicate approximately 1 Ma younger ages as expected from our chronostratigraphic model. This discrepancy is explained by the dominance of freshwater from river discharge contributing high amounts of eroded material to the basin, leading to an increase of the87Sr/86Sr ratio in the shelf-sea water.
Woodlands of the past — The excavation of wetland woods at Zwolle-Stadshagen (the Netherlands): Growth pattern and population dynamics of oak and ash
Authors: Sass-Klaassen U. , Hanraets E. 
Published: April 2016

AbstractDendrochronology has been used to date sub-fossil wood excavated from former wetland woods located in Zwolle-Stadshagen, the Netherlands. Tree-ring analysis was performed on oak and ash to gain insight into changes in the growth dynamics of the trees resulting from changes in external site conditions, particularly hydrology. In addition population dynamics of oak and ash were studied by observing the temporal distribution and mean age of the oak and ash trees in the period when the woodland existed. The results showed that woodlands with oak and ash at Zwolle-Stadshagen existed at least for a period of about 700 years, from ca. 150 BC to AD 580 (ca. 2200 - 1400 cal. BP). The oak and ash were slowly growing and showed alternating phases of normal and depressed growth. Growth depressions occurred with a frequency of about 20 to 40 years. Almost all of these depressions were synchronous with those in oaks from other - mainly wetland areas - in NW Europe. Consequently, a regional (climate) factor must be considered responsible for this phenomenon. By taking into account the specific growth conditions in wetland woods it is very likely that this factor is linked to site hydrology. Around AD 300 (ca. 1650 cal. BP) a remarkable shift in population dynamics occurred in both oak and ash with many new trees establishing. This indicates a period of striking changes in site hydrology preceding the collapse of the woodland starting around AD 530 (ca. 1420 cal. BP).
Modelling the hydrocarbon generation and migration in the West Netherlands Basin, the Netherlands
Authors: van Balen R.T. , van Bergen F. , de Leeuw C. , Pagnier H. , Simmelink H. , van Wees J.D. , Verweij J.M. 
Published: April 2016

AbstractThe hydrocarbon systems of the Mesozoic, inverted West Netherlands Basin have been analyzed using 2-D forward modelling. Three source rocks are considered in the modelling: Lower Jurassic oil-prone shales, Westphalian gas-prone coal deposits, and Lower Namurian oil-prone shales. The Lower Namurian hydrocarbon system of the basin is discussed for the first time.According to the modelling results of the Early Jurassic oil system, the oil accumulations were filled just after the main inversion event. Their predicted locations are in agreement with exploration results. Modelling results of the Westphalian gas system, however, show smaller and larger sized accumulations at unexplored locations. The gas reservoirs were filled during the Late Jurassic-Early Cretaceous rifting phase. Results of modelling of the Lower Namurian oil system indicate that gas formed by secondary cracking of the oils can have mixed with the Westphalian coal-derived gas. Such a mixing is inferred from geochemical analyses. The existence of a Lower Namurian hydrocarbon system in the West Netherlands Basin implies that hydrocarbons are possibly trapped in the Westphalian and Namurian successions. These potential traps in the basin have not yet been explored.
Fracture networks in Rotliegend gas reservoirs of the Dutch offshore: implications for reservoir behaviour
Authors: Gauthier B.D.M. , Franssen R.C.W.M. , Drei S. 
Published: April 2016

AbstractFracture systems of Rotliegend gas fields in and at the margins of the northern Broad Fourteens Basin in the Dutch offshore are described in terms of orientation, frequency, origin and type, and in relation to larger-scale structures. First, fracture data collected from core and image logs have been corrected to account for the bias related to the 1-D sampling. Second, these results were integrated with data on fracture cements and diagenesis in order to assess the timing of the fracture network development.On the basis of their regional extent three phases of fracturing and four orientation trends can be distinguished in the basin:
(1)at Triassic times and related to early diagenesis and burial, NW-SE to NNW-SSE and NE-SW to ESE-WNW particulate-shear fractures developed;(2)during the Mid-Kimmerian and related to the main burial stage, shear-related and dilational-shear-fault-related fracturing occurred parallel with larger-scale faults;(3)during the Cretaceous and related to uplift, NW-SE and NE-SW joints propagated; a regional joint system developed outside the Jurassic rift basin, preferentially oriented E-W to ESE-WNW; these joints have not been dated accurately.The fault-related shear fractures tend to compartmentalise the reservoirs, whereas the regional joints tend to enhance reservoir flow properties. These fracture systems are thought to play a negative or positive role, respectively, but only in fields with poor reservoir quality. Consequently, in such cases small-scale fractures should be taken into account in field development planning.
A seismologically motivated survey of blasting activity in the northern Rhine area
Authors: Hinzen Klaus-G. , Pietsch Stefan 
Published: April 2016

AbstractDiscrimination between quarry blasts and earthquakes has gained importance due to signature of the Comprehensive Test Ban Treaty. In this context, large chemical explosions are significant. In the routine analysis of data from local seismograph networks, discrimination between smaller blasts and micro-earthquakes is not always clear. Many quarries are in operation and blasts far outnumber natural earthquakes in the highly industrialized northern Rhine area.We compiled a list of active quarries in the Northern Rhine Area and mapped their locations. We then created a database from a questionnaire sent out to all quarries on the list. From the 33% of questionnaires that were returned, we discerned some representative values for the main blasting parameters and explosive consumption. In the study area of 72,000 km2, approx. 21,000 blasts are fired per year (80 per working day). Most of the blasts (72%) have total explosive charges between 400 and 4500 kg. Shots with charges above 10 tons are rare (20-30 per year). Some 80% of the blasts are ripple-fired with a nominal firing time interval of 20 ms.Based on empirical amplitude vs. distance curves from vibration control measurements, a relation between maximum charge weight per delay time, L (kg), and a ‘quarry blast’ magnitude, MQB, is derived: MQB= 0.6·log10(L) + 0.131. Using this relation and extrapolating the database from the questionnaire shows that for magnitudes between 1 and 2, blasts occur 200–250 times more frequently than micro-earthquakes in the Northern Rhine area.
Wedge equilibrium in fold-and-thrust belts: prediction of out-of-sequence thrusting based on sandbox experiments and natural examples
Authors: Nieuwland D.A. , Leutscher J.H. , Gast J. 
Published: April 2016

AbstractThrust tectonics are dealt with on the basis of primarily experiments focusing on the dynamics of a developing thrust belt and on understanding and predicting normal-sequence and out-of-sequence thrusting. Field examples are presented in addition to the examples of sandbox-model experiments. The results have improved the insight into thrust-belt-forming mechanisms; the validity of the conclusions is supported by natural examples.The experimental program was aimed at examining the effect of changes in a selection of key parameters in thrust tectonics on the geometry and the successive phases in the development of thrust sheets. Sandbox experiments were used to analyse the effects of basal friction, detachment lithology, basement relief and syntectonic sedimentation. Multilayer experiments were performed to simulate the effects of ductile detachment lithologies.It was found that a thrust belt’s cross-sectional geometry is formed in a dynamic process during which the wedge may develop from subcritical through critical to supercritical and back to critical again. The process is illustrated with sandbox experiments, analysed by time-lapse computed tomography scans and in-situ stress measurements. On the basis of the sandbox-model results and the natural examples, we conclude that a critical examination of the boundary conditions of a fold-and-thrust belt and of changes in these conditions during the deformation process enables predictions about the geometry and kinematics of the thrust belt.
Subaerial terminoglacial fans III: overview of sedimentary characteristics and depositional model
Authors: Zieliński T. , van Loon A.J. 
Published: April 2016

AbstractA general model is presented for the small type of fans (not to be confused with sandurs) that develop subaerially in the zone immediately before an ice front. These fans have in common with other fans that a proximal, a middle and a distal subenvironment– with distinctly different sedimentary facies– can be distinguished. The characteristics of these fans differ in several respects, however, from those formed under other conditions, particularly by the high proportion of mass-flow deposits in the proximal part, by the relative scarcity of fine particles in the middle fan, and by the relatively uniform character of the sediments in the distal fan.The special character of this type of fan is ascribed to the interaction of a continuously changing distance between the ice front and the fan (as a result of alternating phases of ice advance and ice retreat), its position that may be surrounded by ice for a large part, and the irregular supply of debris-laden meltwater that comes sometimes even in the form of more or less catastrophic floods.Due to the fact that terminoglacial fans have a good preservation potential only during phases of ice retreat, these fas tend to show a slight fining-upward tendency. The slope of terminoglacial fans tends to be more gentle (rarely over 2–5°) than that of fans formed under different conditions.
The climatic significance of coleopteran assemblages from the Eemian deposits
in southern England
Authors: Russell Coope G. 
Published: April 2016

Abstract
Assemblages of fossil coleoptera (beetles) have been obtained from eight
sites in southern England that date from the early phase (Pinus —
Quercetum mixtum — Corylus pollen assemblage zone) of the Eemian
(Ipswichian) interglacial Stage. Altogether 294 different species have been
identified from these sites. They represent a wide spectrum of habitat
requirements; terrestrial, aquatic, carnivorous and phytophagous species and many
more with subtle dependences of specialist biotopes. Almost all of them live today
in central and southern Europe and some are restricted to regions well south of
the British Isles.
By using mutual climatic range methods, the thermal climate of the early
phase of the Eemian Interglacial has been estimated quantitatively, showing that
mean July temperatures were about 4°C above those of southern England today. Mean
winter temperatures were not much different from those nowadays. This phase was
probably the thermal maximum of the Eemian Interglacial. Precipitation levels are
difficult to quantify but were adequate to maintain flowing rivers in England
throughout the year. These results are in agreement with the presence of other
fossils, both plants and animals, in the same deposits.
The Eemian mammal fauna of central Europe
Authors: van Kolfschoten Th. 
Published: April 2016

Abstract
The knowledge of the Eemian fauna of central Europe is based on the fossil
record from a number of sites located in the eastern part of Germany. The faunas
with different deer species as well as Sus scrofa, Palaeoloxodon
antiquus, Stephanorhinus kirchbergensis and Glis
glis indicate a forested environment alternating during the
climatic optimum of the Eemian s.s. with areas with a more open environment
inhabited by species such as Cricetus cricetus, Equus
sp. (or Equus taubachensis), Equus
hydruntinus and Stephanorhinus
hemitoechus. Characteristic for the Rhine valley fauna are
Hippopotamus amphibius and the water buffalo
(Bubalus murrensis); both species are absent in the
eastern German faunas with an Eemian age.
Taking into account the short period of time covered by the Eemian s.s., the
amount of data on the Eemian mammalian fauna is remarkably large. There is,
however, still an ongoing debate on whether the stratigraphical position of a
number of faunas are of Eemian or ‘intra-Saalian’ age. Furthermore, there are
faunal assemblages or stratigraphically isolated finds referred to the Eemian
without indisputable evidence. This is particularly the case in the Rhine valley,
where most of the so-called Eemian fossils come from dredged assemblages. The
picture of the evolution of the Eemian fauna and its geographical variation is
consequently still incomplete.
Natural compositional variation of the river Meuse (Maas) suspended load: a 13 ka bulk geochemical record from the upper Kreftenheye and Betuwe Formations in northern Limburg
Authors: Tebbens L.A. , Veldkamp A. , Kroonenberg S.B. 
Published: April 2016

AbstractUnambiguously pristine and largely unpolluted sediments from the Late Weichselian and Holocene infillings of the Meuse residual channels in northern Limburg (the Netherlands) have been sampled to determine the natural compositional variation of the river’s suspended load.Bulk geochemical and granulometric analyses demonstrate that about 70% of the variation can be ascribed to hydrodynamic mineral sorting. Clay- and fine silt-sized phyllosilicates are the most important deterministic features, hosting the bulk of AI2O3, TiO2, K2O, MgO and trace element variability (notably Ba, Cr, Ga, Rb and V). Quartz is abundant in the fine and coarse sand fractions. Na2O and the Zr-Nb-Nd-Y quartet relate to albitic feldspars and heavy minerals, respectively, in the coarse silt fraction. The granulometry should therefore be quantified if geochemical baseline data for a particular geological unit or region are drawn up and for the evaluation of potentially polluted sediments.Although provenance has not changed, the composition of Meuse sediments cannot be considered constant over a time frame of 1000–10,000 years, due to climatic change. Weathering of phyllosilicates in both interstadial and interglacial soil environments and changing relative source-area contributions alter the detrital clay-mineral supply to raise the AI2O3 and lower the K2O and MgO contents in Holocene Meuse sediments. Early diagenetic siderite and vivianite formation in gyttjas causes relative accumulations of Fe2O3, MnO, P2O5, Co, Ni and notably Zn above the phyllosilicate background values. These accumulations are natural and show that sediments with elevated trace metal contents are not necessarily polluted. Very early atmospheric pollution in relation to ore mining and smelting activities in the Roman era, however, probably caused elevated Pb contents in Subatlantic humic clays and peat samples, long before the historic pollution of the Industrial Revolution started.The A12O3, Fe2O3 and CaO contents are used to predict the trace-element values as a function of sample granulometry, siderite/vivianite and lime content, respectively. As such, they can provide a sound basis for environmental researchers to determine baseline values of heavy metals in bulk samples of fine-grained fluvial sediments.
Heavy-metal pollution of the river Rhine and Meuse floodplains in the Netherlands
Authors: Middelkoop H. 
Published: April 2016

AbstractThe embanked floodplains of the lower Rhine river in the Netherlands contain large amounts of heavy metals, which is a result of many years of deposition of contaminated overbank sediments. The metal pollution varies greatly between the various floodplain sections as well as in vertical direction within the floodplain soil profiles. The present contribution describes the key processes producing the spatial variability of the metal pollution in floodplain soils: (1) spatial patterns of the concentrations and deposition of Cd, Cu, Pb and Zn during a single flood, which have been determined from samples collected after a high-magnitude flood event; (2) the pollution trends of the lower Rhine over the past 150 years, which were reconstructed on the basis of metal concentrations in sediments from small ponds within the floodplain area. During the flood the largest metal depositions (0.03 g/m2 Cd, 0.7 g/m2 Cu, 1.1 g/m2 Pb and 5.0 g/m2 Zn for the Rhine) occurred along the natural levees, decreasing to about one third of these values at larger distance from the river. Deposition of heavy metals occurred since the end of the nineteenth century. Periods of maximum pollution occurred in the 1930s and 1960s, when Cu, Pb and Zn concentrations were about 6–10 times as high as background values.The resulting metal distribution in the floodplain soil profiles is illustrated by means of typical examples. Maximum metal concentrations in floodplain soils vary from 30 to 130 mg/kg for Cu, from 70 to 490 mg/kg for Pb, and from 170 to 1450 mg/kg for Zn. The lowest metal pollution is found in the distal parts of floodplain sections with low flooding frequencies, where average sedimentation rates have been less than about 5 mm/a. The largest metal accumulations occur in low-lying floodplain sections where average sedimentation rates have been more than 10 mm/a.