bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silica sand resources in the Netherlands
Authors: van der Meulen M.J. , Westerhoff W.E. , Menkovic A. , Gruijters S.H.L.L. , Dubelaar C.W. , Maljers D. 
Published: July 2016

AbstractSilica sand, (almost) pure quartz sand, is a valuable and scarce mineral resource within the shallow Dutch subsurface. High-grade deposits are exploited in the southeasternmost part of the country, as raw material for the glass, ceramic, chemical and other process industries. Dutch land-use policy requires that scarce mineral resources (including silica sand) are taken into consideration in spatial planning and when preparing for largescale engineering or construction works. For this purpose, and in order to review the long-term possibilities for home production of silica sand, we determined resource potential nationally.Our approach was (1) to establish the relevant conditions and processes associated with the deposition of the currently exploited sands, (2) identify lithostratigraphic units that are genetically similar or are otherwise known to contain quartz-rich sands, and (3) query the Dutch geological survey's borehole database for potential silica sand occurrences within those units. As we have to rely on non-dedicated data, the latter step was undertaken using a largely qualitative set of lithological search parameters. Finally, a limited number of available chemical analyses was used for preliminary verification purposes.Using this approach, we identified three prospective areas: one in the north of the province of Limburg and east of the province of Noord-Brabant(~750 km2), one in the central south of Noord-Brabant (~45 km2), and one in the east of the Gelderland and Overijssel provinces (~1,200 km2). For each area, first-order characteristics of possible silica sand resources are presented (type of deposit, depth, approximate thickness). In the terms of current reporting conventions, we resolved silica sand occurrence to the level of ‘reconnaissance mineral resource’ or ‘exploration result’, and our results do not constitute a formal resource declaration. Available chemical data suggest that the resources in the first two areas could be or become economic, although the grades are lower than those of the currently exploited resources. The third area is less promising in that respect, but available data is too limited to reject the area in this stage. Even so, we tentatively conclude that home production of silica sand can probably be maintained after the reserves in Limburg are depleted.
A new species of the durophagous mosasaur Carinodens (Squamata, Mosasauridae) and additional material of Carinodens belgicus from the Maastrichtian phosphates of Morocco
Authors: Schulp A.S. , Bardet N. , Bouya B. 
Published: July 2016

AbstractFive new dentaries, representing three individuals of the poorly known durophagous mosasaur Carinodens are described from the Maastrichtian phosphates of Morocco. Contrary to previous assumptions, the dentary of Carinodens holds 17-18 teeth, rather than 13. One pair of dentaries represents a new species, Carinodens minalmamar, characterised by laterally flattened teeth with two relatively pronounced sulci, a tooth count of 18, and a more slender general aspect of the dentary itself. The new material requires adjustment of previous reconstructions, assumptions on jaw mechanics, and palaeobiological interpretations of Carinodens.
Assessing CH4 and CO2 emissions from wetlands in the Drenthe Province, the Netherlands: a modelling approach
Authors: Petrescu A.M.R. , van Huissteden J. , de Vries F. , Bregman E.P.H. , Scheper A. 
Published: July 2016

AbstractAssessment of land use related greenhouse gas (GHG) emissions on larger spatial scales is usually achieved by modelling. Surface flux measurements are expensive and measurement locations too widely scattered to serve as spatially reliable flux estimates. Here we assess CO2 and CH4 fluxes from wetland nature reserves in the Dutch province of Drenthe, using the PEATLAND-VU model. Since surface flux observations in the province are absent and cannot be obtained in a short (<1 year) time frame, we extrapolated model validation from elsewhere to the research area. In this way a cost-effective methodology is developed for landuse-related greenhouse gas emission assessments, which can be applied by local governments at a subnational scale.Nature development and restoration in the Netherlands involves usually the restoration of high water tables in former agricultural areas and extensivation or abandonment of agricultural activities. Wet peat soils are known to emit considerable quantities of CH4, while drained agricultural soils emit CO2 from decomposition of the soil organic matter. Therefore, these landuse changes may affect GHG emissions and an assessment of their effects is useful for environmental policy.The PEATLAND-VU Model was used to simulate the CH4 and CO2 emissions for the years 2005-2007 and for May/June 2008. Previous field validation of the model elsewhere was checked for local validity with CH4 and CO2 flux measurements in short field campaigns in May/June 2008, at two locations, Visvliet and Balloërveld. These sites represent respectively eutrophic and oligotrophic peat and peaty soils, and showed large differences in fluxes. These flux differences were simulated correctly by the model by adapting the vegetation net primary production and methane oxidation parameters. Next, model simulations were run for eight combinations of vegetation and soil type. Using the simulated fluxes and the areal extent of the soil combinations, a GIS-based upscaling over all nature reserves was made.This study shows that river valley floors with mesotrophic and eutrophic peat soils dominate the greenhouse fluxes of the area. CH4 fluxes are high in wet terrain, while the CO2 fluxes are high when water table is lower. The fluxes from oligotrophic peat soils are comparatively low. Nature development can contribute to a decrease of the total greenhouse gas flux from peat soils and to conservation of soil organic matter.
Holocene, Weichselian Late-glacial and earlier Pleistocene deposits of the upper Cam valley at the Hinxton Genome Campus, Cambridgeshire, UK
Authors: Boreham S. , Rolfe C.J. 
Published: July 2016

AbstractA section through Pleistocene deposits and temporary exposures of valley-side and valley-fill Late-glacial and Holocene sediments in the upper Cam valley at Hinxton Genome Campus, Cambridgeshire, UK are described. Stratigraphy, radiocarbon dating and pollen analysis are used to create a model of sediment transport, landscape change and vegetation history at the site. This study offers a new understanding of the stratigraphy and context of the Holocene, Weichselian Late-glacial and earlier Pleistocene deposits of the upper Cam valley, and provides an insight into valley-side sediment transport processes and the three-dimensional sediment architecture of the valley-fill sediments.
A late Miocene astropectinid (Echinodermata, Asteroidea) and associated ichnofossils from Liessel, province of Noord-Brabant, the Netherlands
Authors: Jagt J.W.M. , Fraaije R.H.B. , van Bakel B.W.M. 
Published: July 2016

AbstractA fragmentary and partially dissociated arm of an astropectinid starfish, assigned to the genusAstropectenGray, 1840, is recorded from decalcified and limonitised, fine-grained sandstone concretions and slabs of late Miocene (Tortonian) age, collected from the former gravel and sand pit ‘de Hoogdonk’ near Liessel, province of Noord-Brabant. Added are two examples of the ichnofossilAsteriacites lumbricalisvon Schlotheim, 1820, both preserved in convex hyporelief and co-occurring with other, indeterminate traces. Although astropectinids have been recorded previously from Miocene and Pliocene deposits in the Netherlands, the present is the first record of fossilised traces of starfish.
A tribute to the late Felder brothers – pioneers of Limburg geology and prehistoric archaeology; introduction
Authors: Jagt J.W.M. , Jagt-Yazykova E.A. , Schins W.J.H. 
Published: July 2016

AbstractAll contributions in the current memorial volume are briefly commented upon, with the emphasis on how these issues touched upon, or were linked to, the long and productive professional careers of the late Felder brothers, in the fields of geology, palaeontology and human prehistory. Pertinent literature references are added, some of which are covered in the various papers, while others illustrate their wide range of interests and prolific publishing lives.
Leymeriaster campestris, a new early Campanian hemiasterid echinoid from southern Limburg, the Netherlands
Authors: van der Ham R.W.J.M. , Jagt J.W.M. , Janssens H.J. 
Published: July 2016

AbstractIn the type area of the Maastrichtian Stage (northeast Belgium, southeast Netherlands), two species of the rare hemiasterid echinoid genusLeymeriasterwere known to date. Here we describe a third,L. campestrissp. nov., from the so-called ‘Laagje van Müller’ (Gemmenich Member, Vaals Formation) at Vaals-Eschberg, southern Limburg (the Netherlands), which is of early Campanian age. It differs from its late Maastrichtian congeners in the area,L. maestrichtensisandL. eluvialis, in that the pore pairs in the frontal groove of ambulacrum III are not in small depressions and the adjacent interambulacral margins are not thickened, raised and/or overhanging. It differs fromL. maestrichtensisby the lack of a clear notch in the ambitus in ambulacrum III, and fromL. eluvialisin the presence of a distinctly longer groove in ambulacrum III.Leymeriaster campestrissp. nov. is the first undoubted species of CampanianLeymeriasterknown from northwest Europe.
Late Middle Pleistocene glaciofluvial sedimentation in western Norfolk, England
Authors: Gibbard P.L. , Boreham S. , West R.G. , Rolfe C.J. 
Published: July 2016

AbstractInvestigation of landforms on the eastern margin of the East Anglian Fenland basin has demonstrated that they represent a series of glaciofluvial delta-fan and related sediment accumulations (the Skertchly Line) deposited at the margin of an ice-lobe that entered the depression. This ‘Tottenhill glaciation’ dated to ca 160 ka, or the late Wolstonian (= late Saalian) Stage, is equivalent to that during the Netherlands' Drenthe Substage (Marine Isotope Stage 6). Of these landform complexes, an additional site at Shouldham Thorpe, previously nominated as the stratotype for deposits linked to a pre-Anglian Stage, Midlands'-derived Ingham/‘Bytham river’, has now been studied. Examination of the internal structure and form of the feature, using ground-penetrating radar (GPR), supported by section logging, borehole records, local landscape morphology and previous description, together indicate that the deposits rest on an eroded surface of Lowestoft Formation diamicton (Anglian Stage) and must therefore be of post-, rather than pre-Anglian age. The investigations indicate that the Shouldham deposits were laid down as a glacio-marginal subaerial (‘terminoglacial’) fan at the ice-front. In common with other sequences in the Skertchly Line complexes, deposition at Shouldham Thorpe was accompanied by minor ice-front movement, this fan potentially being deposited before retreat to the Tottenhill locality. The implications of the results are discussed.
The Pleistocene terrace staircases of the present and past rivers downstream from the Vosges Massif (Meuse and Moselle catchments)
Authors: Harmand D. , Cordier S. 
Published: July 2016

AbstractThis paper aims to provide a synthesis and update concerning the fluvial terraces of the rivers flowing from the Vosges Massif (Moselle and palaeo Upper-Moselle-Meuse, Meurthe, Sarre). The terraces of these rivers are especially well-developed in the marly depressions of the Eastern Paris Basin, justifying an extensive field mapping expedition. The main rivers exhibit terrace staircases with 8 to 13 stepped terrace steps within 100m of the present valley floor. The fluvial sediments mainly originate from the Vosges Massif (crystalline basement and Permo-Triassic sandstones and conglomerates). Another peculiarity of the study area is the presence of several palaeovalleys, typically related to fluvial capture events which occurred to the detriment of the River Meuse. Many palaeomeanders have also been recognised in the Paris Basin (Meuse catchment), and the Rhenish Massif (Moselle and Sarre valleys). Despite some similarities, palaeoenvironmental reconstructions provide evidence for the terrace staircases being distinct from one valley / section of valley to another. These differences are related to the morphostructural framework and to the climate forcing (presence/absence of glaciers in the upper catchment of the rivers). The chronological framework suggests that the terrace sequences and the main capture events may be older than previously thought.
Fluvial and aeolian landscape evolution in Hungary – results of the last 20 years research
Authors: Gábris Gy. , Horváth E. , Novothny Á. , Ruszkiczay-Rüdiger Zs. 
Published: July 2016

AbstractPresent 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.
Geomorphologic context and proposed chronostratigraphic position of Lower Palaeolithic artefacts from the Op de Schans pit near Kesselt (Belgium) to the west of Maastricht
Authors: Meijs E.P.M. , van Peer Ph. , de Warrimont J.P.L.M.N. 
Published: July 2016

AbstractIn July 2007 an important archaeological find was made in the Op de Schans loess pit near Kesselt (Belgian Limburg) immediately to the west of the Dutch city of Maastricht. During an archaeological rescue dig, three Lower Palaeolithic artefacts were recovered from the infill of an ancient erosion gully: a bifacial side-scraper, an atypical biface and a cortical flake. Typologically, the artefacts can be classified as Acheulean. In this region, harbouring several such brickyard pits, these are the oldest artefacts yet found, prompting further investigations into the stratigraphic position of the archaeological layer. The Op de Schans pit, which has yielded several Middle Palaeolithic occupation horizons, is located in the middle of an ancient sediment trap. Because of this exceptional geomorphologic situation, multiple ancient sediments have been preserved which elsewhere were entirely removed during subsequent erosion phases. Here five separate loess beds with intercalated interglacial palaeosols are present, overlying the deposits of the River Maas (Meuse). This sequence has been used as a hypothetical framework for elaborating a chronostratigraphic model. The archaeological level in question, discovered at the base of a subsequently infilled erosion gully, can most likely be chronostratigraphically dated to around the start of Marine Isotope Stage 10 (MIS 10), in the era of the Pottenberg discordance (approx. 390 ka). However, the possibility cannot be excluded that the gully in which the artefacts were found dates from an early phase of MIS 12 (approx. 480 ka). The age may in fact be greater still, as the artefacts have been eroded out of their original, primary context and subsequently deposited in the gully. Hypothetically, they may even have been taken up from the Maas loam of the Kesselt Maas terrace (MIS 13) that here is situated directly below the archaeological horizon. This would make the maximum age of the artefacts recovered from the gully around 500 ka.
Palaeoclimatic changes in northeastern Qinghai-Tibetan Plateau revealed by magnetostratigraphy and magnetic susceptibility analysis of thick loess deposits
Authors: Lu H.Y. , Wang Xianyan , Wang Xiaoyong , Sun X.F. , Yi S.W. , Zhou Y.L. , Liu Q.Y. , Swinehart J. , Vandenberghe J. 
Published: July 2016

AbstractReconstruction of a complete Quaternary record of climatic changes in the northeastern Qinghai-Tibetan Plateau is not well obtained, because of high relief and extensive surface erosion. In this study, two long cores obtained from thick loess deposits in the region, both contain clear alternations of loess and paleosols, indicating distinct climate changes during the Quaternary. The palaeomagnetic stratigraphy and optically stimulated luminescence dating indicate that the loess deposition began approximately 2.0 Ma ago, with continuous accumulation until the Holocene. Dust accumulation rates in this region are much higher than those in the central Chinese Loess Plateau, suggesting an extended dust source and/or robust transport agent. Variations of magnetic susceptibility of the loess are a good proxy index of warm/wet and cold/dry alternations and are correlated with the intensity of pedogensis. The magnetic susceptibility record reveals that a relatively cold/dry climate dominated the northeastern Qinghai-Tibetan Plateau in the Quaternary, punctuated by warm/wet phases. A stepwise strengthening of the plateau summer monsoon, with a significant strengthening at around 1200-1000 ka and at least 7 phases of strengthening of the plateau summer monsoon in the past 800 ka are interpreted from the core data. The cores provide evidence that strengthened warm/wet climates occurred at around 80-130, 190-250, 290-340, 385-420, 500-625, 690-720 and 755-780 ka, which may correlate to warm/wet phases in the Qinghai-Tibetan Plateau. The palaeoclimate changes probably were regulated by the glacial-interglacial alternations.
Changing depositional environments in the Colombian Fúquene Basin at submillennial time-scales during 284-27 ka from unmixed grain-size distributions and aquatic pollen
Authors: Vriend M. , Groot M.H.M. , Hooghiemstra H. , Bogotá-Angel R.G. , Berrio J.C. 
Published: July 2016

AbstractIn a ~60 m long record reflecting the period from 284 ka to 27 ka we analysed grain size distributions (GSD), organic carbon content, and aquatic pollen assemblages at 1-cm increments. The 4768-points time series show with ~60 yr resolution the dynamic history of Lake Fúquene (2540 m alt., 4° N lat.) of the northern Andes during two full interglacial-glacial cycles. GSD show proportions of clay, fine silt, coarse silt, and sand evidencing the location of the sediment source (proximal vs distal) in relation to the drilling site, and available energy to transport sediments in the catchment area. Loss-on-ignition (LOI) values reflect estimates of the abundance of organic matter (OM) in the sediments. Aquatic pollen were grouped into assemblages characteristic of deep water, shallow water, swamp, and wet lake shore environments, reflecting a hydrological gradient sensitive for lake level changes.The End-Member Modelling Algorithm (EMMA) showed that 4 end-members (EMs) explain an optimal proportion (70%) of the observed variation. EMMA is able to unmix GSD of lacustrine sediments in a genetically meaningful way allowing EMs to be interpreted in past depositional and environmental settings. Most unexplained variability is located in the fraction of coarse sediment. OM content was estimated on the basis of LOI data and formed a fifth EM that mainly indicates presence of peat. Changes concur with submillennial-scale variability established in other proxies from this record (Groot et al., 2011). Periods with distinct sediment compositions are 284-243 ka (mainly MIS 8), 243-201 ka (mainly MIS 7), 201-179 ka (mainly MIS 7/6 transition), 179-133 ka (mainly MIS 6), 133-111 ka, (mainly MIS 5e) 111-87 ka (mainly MIS 5d-5b), 87-79 ka (mainly MIS 5a), 79-62 ka (mainly MIS 4), and 62-27 ka (MIS 3) showing sedimentological regimes are climate driven.
Studies in the Lichen Family Pannariaceae VII. on Some Poorly Known Parmeliella-Like Species from the Southern Hemisphere.
Authors: Jørgensen Per M. 
Published: July 2016

AbstractTwoParmeliella-like lichen species are described as new:Santessoniella pulchella, known from warm temperate parts of eastern Australia and northern New Zealand, andSiphulastrum squamosum, a relatively common species on stumps ofNothofagusin southern Chile. Both differ fromParmeliellas. str. in the hemiamyloid, finally red-brown hymenial iodine reaction and the apical structures of the asci, as well as in thallus details (anatomy and chemistry).Parmeliella majorDarb. is a synonym ofP. thysanota(Sirt.) Zahlbr., which thus proves to be a circumpolar species in the Southern Hemisphere, though not yet discovered in South Africa. A new species,Parmeliella lacerate, is described from the Republic of South Africa, and related toParmeliella chilensis(Hue) P. M. Jørg., comb. nov.
A Sum Connected with Quadratic Residues
Authors: Carlitz L. 
Published: July 2016

Let p be a prime > 2 and m an arbitrary positive integer; definewhere (r/p) is the Legendre symbol. We consider the problem of finding the highest power of p dividing Sm. A little more generally, if we putwhere a is an arbitrary integer, we seek the highest power of p dividing Sm(a). Clearly Sm = Sm(0), and Sm(a) = Sm(b) when a ≡ b (mod p).
On a proof of divisibility lemma, I
Authors: Shikata Y. , Klingenberg W. 
Published: July 2016

A method to show the existence of infinitely many closed geodesies on a manifold with non degenerate Riemannian metric is to use socalled divisibility lemma which is conjectured to hold in [K].Our purpose in this series of papers is, then, to show first the divisibility lemma in a modified form on k-sphere Sk (k≧3) with (strongly) non degenerate Riemannian metric and to deduce the existence of infinitely many closed geodesies on Sk (k≧3) using the modified divisibility lemma by equivariant modifications of flows.
The modular equation and modular forms of weight one
Authors: Hiramatsu Toyokazu , Mimura Yoshio 
Published: July 2016

This is a continuation of the previous paper [8] concerning the relation between the arithmetic of imaginary quadratic fields and cusp forms of weight one on a certain congruence subgroup. Let K be an imaginary quadratic field, say K = with a prime number q ≡ − 1 mod 8, and let h be the class number of K. By the classical theory of complex multiplication, the Hubert class field L of K can be generated by any one of the class invariants over K, which is necessarily an algebraic integer, and a defining equation of which is denoted byΦ(x) = 0.