bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paléoenvironnements tropicaux, marins et lagunaires d'un littoral abrité (fonds meubles à bancs coralliens, lagune évaporitique) à l'Oligocène terminal, en Basse-Provence (région d'Aix-en-Provence, Marseille, France)
Authors: Nury Denise , Thomassin Bernard Armand 
Published: September 2018

Les phénomènes distensifs qui ont régné durant tout l'Oligocène prennent à l'Oligocène terminal une ampleur nouvelle, à l'origine de la création de la Méditerranée occidentale (phénomène de rifting) dont le rivage s'établit en bordure méridionale actuelle de la chaîne de la Nerthe. Or, d'après des travaux récents, les niveaux marins de Carry-le-Rouet appartiennent au même niveau stratigraphique que la formation laguno-lacustre à gypse du bassin d'Aix-en-Provence : Chattien terminal.
Les dépôts marins de Carry sont constitués, en particulier, de formations coralliennes (successions de biostromes, bancs coralliens de faibles épaisseurs, colonies coralliennes dispersées) associées à des formations sédimentaires détritiques de faible énergie. Ce paléoenvironnement correspond à un contexte de mer ouverte, mais en mode particulièrement calme de bordure de rift, similaire à certains contextes modernes de récifs frangeants en mode calme.
Les dépôts laguno-lacustres, essentiellement carbonatés (calcaires et marnes généralement laminaires et en petits bancs), s'effectuent dans un milieu à salinité variable qui peut aller de la dessalure totale à une concentration telle qu'elle permettait la précipitation des sulfates (gypse). Le milieu évoque celui d'un marais maritime intermittent. Ce milieu laguno-lacustre est alternativement séparé ou ouvert sur la mer par l'intermédiaire de passage(s) à travers un seuil d'origine tectonique (massif de la Nerthe), jouant grâce aux mouvements verticaux distensifs associés aux épisodes de rifting.
Cette situation n'est pas sans rappeler celle observée aujourd'hui sur certaines portions de littoral de la Mer Rouge ou du Golfe Persique.
Paléogéographie du Bassin du Chélif (Algérie) au Miocène. Causes et conséquences
Authors: Neurdin-Trescartes Jacqueline 
Published: September 2018

La paléogéographie du Bassin du Chélif (Algérie) au Miocène a été tracée à partir de levers de terrain et d'analyses de laboratoire. Induite par la tectonique, l'eustatisme, le climat, cette paléogéographie a varié dans le temps et dans l'espace. Les variations importantes de faciès sont intimement liées à des types d'apports différents :
-au Nord, apports directs au droit de massifs bordiers en voie de surrection,
-au Sud, apports lointains au niveau de Medea et de Bou Hanifia,
-à l'Est, présence de courants "longshore" apportant du matériel depuis la Krouminie.
Contribution à l'étude palynologique et paléoenvironnementale du Campanien et du Maastrichtien du bassin offshore de Côte d'Ivoire
Authors: Digbehi Bruno Zeliche , Yao K.R. , Téa Y.J. , Boblaï G. 
Published: September 2018

L'étude palynologique de l'intervalle 1240-1720 m d'un puits pétrolier situé dans la partie "offshore" du bassin sédimentaire de Côte d'Ivoire, a révélé une palynoflore riche en dinokystes fortement représentés par les genres Palaeocystodinium, Senegalitiium, Dinogymnium, Cerodinium, Andalusiella, Xenascus, Hystrichodinium et Trichodinium.
Les spores et grains de pollen de cet intervalle sont peu nombreux et proviennent essentiellement de Ptéridophytes (Cyathéacées, Polypodiacées et Ophiglossacées) et d'Angiospermes (monocotylé-dones et dicotylédones) ; ces taxons botaniques suggèrent un paléoclimat tropical chaud et humide.
La répartition verticale de cette palynoflore a mis en évidence quatre associations caractéristiques allant du Campanien inférieur au Maastrichtien supérieur. L'analyse du palynofaciès et de l'environnement de dépôt le long de l'intervalle a montré des fluctuations du niveau marin sur le plateau continental interne.
Analogue models of alluvial doline development
Authors: Soriano M.A , Simón José Luis 
Published: September 2018

Quaternary terraces of the Ebro river near Zaragoza show many alluvial dolines developed owing to dissolution of Miocene gypsum. Five main factors control the doline distribution at a 1 : 50 000 scale :
1. low sulphate content in water,
2. high annual variations of the water table,
3. "palaeovalleys" in the Tertiary/Quaternary boundary,
4. thickness of the Quaternary cover and
5. low lutite percentage.
Ten small-scale experiments, which were carried out using a salt substratum below a sand or silt cover, corroborate the importance of the last three variables. Experimental dolines first appear over trenches of the soluble substratum, in thin cover areas or where the grain size of the cover was coarse. The two main types of surface morphology (basin, well) appear in good correlation with two types of internal structure (funnel, vault) and two basic mechanisms of evacuation and sinking (dragging + slow subsidence, solution voids + sudden collapse).
Stratigraphy of the Kuwait Group in Umm -Gudair and Surrounding areas, Kuwait
Authors: Al-Rawdan Z. , Al-Ruwaih F.M. , Ozkaya S.I. 
Published: September 2018

Stratigraphy of the Miocene-Pleistocene Kuwait Group is studied on the basis of core samples and bore-hole logs from Umm-Gudair, NW Al-Shagaya, Al-Salmi, Al-Wafra water wells, exposures at Jal Az-Zor escarpment and Ahmadi quarry. The over all stratigraphie sequence of the Kuwait Group bear clues for a gradual regional regression and accompanying increase in clastic material influx. The Kuwait Group starts with marine clays and continues upward as fluvial, river channel sands, and ends with alluvial fan conglomerates. Deposition of the Kuwait group was interpreted frequently by brief periods of quiescence and non-deposition. Pauses in sedimentation are marked by surfaces of carbonate and gypsum cementation in the pore spaces of sands by evaporation of capillary water, and alteration of clays. The lower parts of the Kuwait Group consist mostly of loose sands without cementation. The degree of cementation and frequency of cemented layers increase towards the top of the group.
The Kuwait Group is subdivided into three formations in the pre¬ sent study from bottom to top. These are Ghar, Jal Az-Zor and Dibdibba Formations. The fossiliferous sandy limestone layer at the lower part of the group was selected as the boundary between Ghar and the overlying Jal Az-Zor Formations. The boundary between the Jal Az-Zor and Dibdibba Formations is hard to locate. The carbonate-cemented sand layers are included in the Jal Az-Zor, and overlying poorly-bedded and weakly cemented gravels are included in the Dibdibba Formation. Subsurface correlation suggests that the thickness of Ghar and Jal Az-Zor Formations are uniform, but Dibdibba Formation varies in thickness from north to south.
Carbon isotope stratigraphy of the lower Aptian historical stratotype at Cassis-La Bédoule (SE France)
Authors: Kuhnt Wolfgang , Moullade Michel , Masse Jean-Pierre , Erlenkeuser Helmut 
Published: September 2018

Stratigraphie isotopique (δ°C) de l'Aptien inférieur (Bédoulien) du stratotype historique de Cassis-La Bédoule (SE France). Une stratigraphie isotopique (δ°C en %c PDB) à haute résolution a été établie sur roche totale à partir des carbonates du Barrémien terminal et de l'Aptien inférieur des coupes de la Gare de Cassis et des Sardons à La Bédoule (SE France), stratotype historique de l'Aptien inférieur (Bédoulien). Dans ce secteur, la période correspondant à ce sous-étage est marquée par un fort taux de sédimentation, avec une centaine de mètres de dépôts à dominante carbonatée et à faciès hémipéiagique. Cette dilatation exceptionnelle de la série a permis de mettre nettement en évidence deux déflections positives de la courbe du 513C. La première débute immédiatement après la limite Barrémien/Aptien et atteint des valeurs maximales du δ°C de 3,5 %o dans le Bédoulien inférieur, au sein de la zone de foraminifères planctoniques à Praehedbergella kuznetsovae. Une seconde déflec-tion, plus significative, située dans la partie moyenne du Bédoulien supérieur, commence au sommet de la zone à Blowiella blowi et atteint son maximum, avec des valeurs du δ°C supérieures à 4,5 %o, au Bédoulien terminal (partie supérieure de la zone à Schackoina cabri).
La seconde déflection a déjà été reconnue en d'autres sites de la Tethys, comme Gorgo a Cerbara (Italie), le Domaine Vocontien (S.E. France), ou Cismon dans les Alpes Méridionales, ainsi qu'en Oman. En revanche la première semble uniquement enregistrée dans les localités à fort taux d'accumulation des carbonates, comme La Bédoule, et pourrait être masquée par suite d'une forte condensation ou d'un hiatus à ce niveau dans les localités étudiées jusqu'à présent.
Les Foraminifères benthiques et planctoniques du stratotype historique de l'Aptien inférieur dans la région de Cassis-La Bédoule (SE France)
Authors: Moullade Michel , Tronchetti Guy , Kuhnt Wolfgang , Masse Jean-Pierre 
Published: September 2018

Benthic and planktonic Foraminifers from the lower Aptian historical stratotype in the Cassis-La Bédoule area (SE France).
A taxonomic update and detailed study of foraminiferal vertical distribution in the Bedoulian type section allowed us to define local assemblages, which characterize individual lithological units. Based on the occurrence of several planktonic foraminiferal datums, we confirm the zonation already established for SE France, which includes the Praehedbergella kuznetsovae Zone ("latest Barremian-early Bedoulian), the Blowiella blowi Zone (early late Bedoulian) and the Schackoina (Leupoldina ) cabri Zone (latest Bedoulian and earliest Gargasian). Changes in the composition of the foraminiferal assemblages provide also some information on the evolution of the paleoenvironment. Our data suggest a moderate and more or less continuous increase of the water depth, from few meters overlying the Urgonian platform during the late Barremian to one or more likely two hundred meters during the Bedoulian-Gargasian transition. Productivity and temperature seem also to globally increase during the Bedoulian, but with jerks and flash-back suggesting some second-order cyclicity. The foraminiferal compositional changes permit also to show that a momentaneous oxygenation crisis occurred during the late Bedoulian, without any obvious lithological expression. This brief dysoxic period might evoke the Goguel (Vocontian domain) or Selli (N. Italy) levels, corresponding to the global OAE 1a event.
L'Anti-Atlas occidental du Maroc : remplissage sédimentaire d'un bassin de type rift intracontinental au Cambrien inférieur
Authors: Benssaou M. , Hamoumi Naïma 
Published: September 2018

Dans l'Anti-Atlas occidental, la caractérisation stratigraphique et sur¬ tout sédimentologique, (identification des faciès et reconstitution des paléo-environnements) des formations attribuées au Cambrien inférieur, permet de mettre en évidence deux phases de remplissage d'un bassin de type rift intracontinental avorté : une phase synrift et une phase post-rift. Chaque phase est représentée par une série sédimentaire.
La série qui représente la phase synrift constitue le comblement partiel d'un bassin de type rift continental. Le développement de ce bassin, initié durant l'événement distensif du Paléozoïque inférieur, peut être ramené à deux événements tectoniques essentiels : la première étape d'individualisation, représentée par le groupe d'Anzi, est limitée à l'axe Anzi-Ait Abdallah et la deuxième, représentée par le groupe d'Asghrkyis, est marquée par l'extension de la distension qui atteint le Nord de la boutonnière de Kerdous.
Durant la phase postrift, l'étude sédimentologique et lithostratigraphique des formations sédimentaires de la série représentative a permis d'élaborer un découpage lithostratigraphique en séquences composites et en séquences élémentaires. Les deux groupes sédimentaires reconnus dans la région traduisent une phase de stabilité tectonique relative associée à une remontée eustatique de grande ampleur (groupe de Madaw) et une phase, représentée par le groupe d'Ait Abdallah, marquée par le contrôle tectonique et eustatique de la sédimentation et de son organisation séquentielle.
Beyond the Coronal Graveyard
Authors: Ayres Thomas R. 
Published: September 2018

Abstract
New Chandra High Resolution Camera pointings on the “non-coronal” red giant Arcturus (HD 124897; α Boo: K1.5 III) corroborate a tentative soft X-ray detection in a shorter exploratory exposure 16 years earlier. The apparent source followed the (large) proper motion of the nearby bright star over the intervening years, and there were null detections at the previous location in the current epoch, as well as at the future location in the earlier epoch, reducing the possibility of chance coincidences with unrelated high-energy objects. The apparent X-ray brightness at Earth, averaged over the 98 ks of total exposure and accounting for absorption in the red giant’s wind, is ∼2 × 10−15 erg cm−2 s−1 (0.2–2 keV). Systematic errors in the energy conversion factor, devolving from the unknown spectrum, amount to only about 10%, smaller than the ∼30% statistical uncertainties in the count rates. The X-ray luminosity is only 3 × 1025 erg s−1, confirming Arcturus as one of Chandra’s darkest bright stars.
ALMA Thermal Observations of Europa
Authors: Trumbo Samantha K. , Brown Michael E. , Butler Bryan J. 
Published: September 2018

Abstract
We present four daytime thermal images of Europa taken with the Atacama Large Millimeter Array. Together, these images comprise the first spatially resolved thermal data set with complete coverage of Europa’s surface. The resulting brightness temperatures correspond to a frequency of 233 GHz (1.3 mm) and a typical linear resolution of roughly 200 km. At this resolution, the images capture spatially localized thermal variations on the scale of geologic and compositional units. We use a global thermal model of Europa to simulate the ALMA observations in order to investigate the thermal structure visible in the data. Comparisons between the data and model images suggest that the large-scale daytime thermal structure on Europa largely results from bolometric albedo variations across the surface. Using bolometric albedos extrapolated from Voyager measurements, a homogenous model reproduces these patterns well, but localized discrepancies exist. These discrepancies can be largely explained by spatial inhomogeneity of the surface thermal properties. Thus, we use the four ALMA images to create maps of the surface thermal inertia and emissivity at our ALMA wavelength. From these maps, we identify a region of either particularly high thermal inertia or low emissivity near 90° west and 23° north, which appears anomalously cold in two of our images.
nbodykit: An Open-source, Massively Parallel Toolkit for Large-scale Structure
Authors: Hand Nick , Feng Yu , Beutler Florian , Li Yin , Modi Chirag , Seljak Uroš , Slepian Zachary 
Published: September 2018

Abstract
We present nbodykit, an open-source, massively parallel Python toolkit for analyzing large-scale structure (LSS) data. Using Python bindings of the Message Passing Interface, we provide parallel implementations of many commonly used algorithms in LSS. nbodykit is both an interactive and scalable piece of scientific software, performing well in a supercomputing environment while still taking advantage of the interactive tools provided by the Python ecosystem. Existing functionality includes estimators of the power spectrum, two- and three-point correlation functions, a friends-of-friends grouping algorithm, mock catalog creation via the halo occupation distribution technique, and approximate N-body simulations via the FastPM scheme. The package also provides a set of distributed data containers, insulated from the algorithms themselves, that enables nbodykit to provide a unified treatment of both simulation and observational data sets. nbodykit can be easily deployed in a high-performance computing environment, overcoming some of the traditional difficulties of using Python on supercomputers. We provide performance benchmarks illustrating the scalability of the software. The modular, component-based approach of nbodykit allows researchers to easily build complex applications using its tools. The package is extensively documented at http://nbodykit.readthedocs.io, which also includes an interactive set of example recipes for new users to explore. As open-source software, we hope nbodykit provides a common framework for the community to use and develop in confronting the analysis challenges of future LSS surveys.
The Steady Global Corona and Solar Wind: A Three-dimensional MHD Simulation with Turbulence Transport and Heating
Authors: Usmanov Arcadi V. , Matthaeus William H. , Goldstein Melvyn L. , Chhiber Rohit 
Published: September 2018

Abstract
We present a fully three-dimensional magnetohydrodynamic model of the solar corona and solar wind with turbulence transport and heating. The model is based on Reynolds-averaged solar wind equations coupled with transport equations for turbulence energy, cross helicity, and correlation scale. The model includes separate energy equations for protons and electrons and accounts for the effects of electron heat conduction, radiative cooling, Coulomb collisions, Reynolds stresses, eddy viscosity, and turbulent heating of protons and electrons. The computational domain extends from the coronal base to 5 au and is divided into two regions: the inner (coronal) region, 1–30 R
☉, and the outer (solar wind) region, 30 R
☉–5 au. Numerical steady-state solutions in both regions are constructed by time relaxation in the frame of reference corotating with the Sun. Inner boundary conditions are specified using either a tilted-dipole approximation or synoptic solar magnetograms. The strength of solar dipole is adjusted, and a scaling factor for magnetograms is estimated by comparison with Ulysses observations. Except for electron temperature, the model shows reasonable agreement with Ulysses data during its first and third fast latitude transits. We also derive a formula for the loss of angular momentum caused by the outflowing plasma. The formula takes into account the effects of turbulence. The simulation results show that turbulence can notably affect the Sun’s loss of angular momentum.
Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging
Authors: Gennaro G. Di , van Weeren R. J. , Hoeft M. , Kang H. , Ryu D. , Rudnick L. , Forman W. , Röttgering H. J. A. , Brüggen M. , Dawson W. A. , Golovich N. , Hoang D. N. , Intema H. T. , Jones C. , Kraft R. P. , Shimwell T. W. , Stroe A. 
Published: September 2018

Abstract
Despite the progress that has been made in understanding radio relics, there are still open questions regarding the underlying particle acceleration mechanisms. In this paper, we present deep 1–4 GHz Very Large Array (VLA) observations of CIZA J2242.8+5301 (z = 0.1921), a double radio relic cluster characterized by small projection on the plane of the sky. Our VLA observations reveal, for the first time, the complex morphology of the diffuse sources and the filamentary structure of the northern relic. We discover new, faint, diffuse radio emission extending north of the main northern relic. Our Mach number estimates for the northern and southern relics, based on the radio spectral index map obtained using the VLA observations and existing LOw Frequency ARray (LOFAR) and Giant Metrewave Radio Telescope data, are consistent with previous radio and X-ray studies (

and

). However, color–color diagrams and models suggest a flatter injection spectral index than the one obtained from the spectral index map, indicating that projection effects might be not entirely negligible. The southern relic consists of five “arms.” Embedded in it, we find a tailed radio galaxy that seems to be connected to the relic. A spectral index flattening, where the radio tail connects to the relic, is also measured. We propose that the southern relic may trace AGN fossil electrons that are reaccelerated by a shock, with an estimated strength of

. High-resolution mapping of other tailed radio galaxies also supports a scenario where AGN fossil electrons are revived by the merger event and could be related to the formation of some diffuse cluster radio emission.
Glitch Rises as a Test for Rapid Superfluid Coupling in Neutron Stars
Authors: Graber Vanessa , Cumming Andrew , Andersson Nils 
Published: September 2018

Abstract
Pulsar glitches provide a unique way to study neutron star microphysics because short post-glitch dynamics are directly linked to strong frictional processes on small scales. To illustrate this connection between macroscopic observables and microphysics, we review calculations of vortex interactions focusing on Kelvin wave excitations and determine the corresponding mutual friction strength for realistic microscopic parameters in the inner crust. These density-dependent crustal coupling profiles are combined with a simplified treatment of the core coupling and implemented in a three-component neutron star model to construct a predictive framework for glitch rises. As a result of the density-dependent dynamics, we find the superfluid to transfer angular momentum to different parts of the crust and the core on different timescales. This can cause the spin frequency change to become non-monotonic in time, allowing for a maximum value much larger than the measured glitch size, as well as a delay in the recovery. The exact shape of the calculated glitch rise is strongly dependent on the relative strength between the crust and core mutual friction, providing the means to probe not only the crustal superfluid but also the deeper neutron star interior. To demonstrate the potential of this approach, we compare our predictive model with the first pulse-to-pulse observations recorded during the 2016 December glitch of the Vela pulsar. Our analysis suggests that the glitch rise behavior is relatively insensitive to the crustal mutual friction strength as long as



≳ 10−3, while being strongly dependent on the core coupling strength, which we find to be in the range

3
×

10

−
5

≲



core

≲

10

−
4

.
Halos in Dark Ages: Formation and Chemistry
Authors: Novosyadlyj B. , Shulga V. , Han W. , Kulinich Yu. , Tsizh M. 
Published: September 2018

Abstract
Formation of halos in the dark ages from initial spherical perturbations is analyzed in a four-component universe (dark matter, dark energy, baryonic matter, and radiation) in the approximation of relativistic hydrodynamics. Evolution of density and velocity perturbations of each component is obtained by integration of a system of nine differential equations from z = 108 up to virialization, which is described phenomenologically. It is shown that the number density of dark matter halos with masses M ∼ 108–109
M
⊙ virialized at z ∼ 10 is close to the number density of galaxies in comoving coordinates. The dynamical dark energy of classical scalar field type does not significantly influence the evolution of the other components, but dark energy with a small value of effective sound speed can affect the final halo state. Simultaneously, the formation/dissociation of the first molecules has been analyzed in the halos that are forming. The results show that number densities of molecules H2 and HD at the moment of halo virialization are ∼103 and ∼400 times larger, respectively, than on a uniformly expanding background. This is caused by increased density and rates of reactions at quasi-linear and nonlinear evolution stages of density and velocity of the baryonic component of halos. It is shown also that the temperature history of the halo is important for calculating the concentration of molecular ions with low binding energy. Hence, in a halo with virial temperature ∼105 K the number density of the molecular ion HeH+ is approximately 100 times smaller than that on the cosmological background.