1,615 research outputs found

    Fractional-order logistic differential equation with Mittag–Leffler-type Kernel

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    In this paper, we consider the Prabhakar fractional logistic differential equation. By using appropriate limit relations, we recover some other logistic differential equations, giving representations of each solution in terms of a formal power series. Some numerical approximations are implemented by using truncated series.Agencia Estatal de InvestigaciĂłn | Ref. PID2020-113275GB-I00Xunta de Galicia | Ref. ED431C 2019/0

    Petrology and structure of Campanario-La Haba pluton and Los Berrocales stock (Badajoz): preliminary dates

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    [Abstract] The Campanario-La Haba pluton and Los Berrocales stock are situated in the southern part ofthe Central-Iberian zone. They form part ofthe late-Hercynian alignement named Caceres-Linares or Pedroches-Alburquerque. During the last years these two granitoids have been related, based on spatial and/or genetic criteria, with Los Pedroches Batholith. These igneous bodies are different. Campanario-La Haba pluton is a coarse grained peraluminous granite with large megaphenocrysts ofcordierite. Three facies are differenciated based on petrographic criteria: coarse grained porfiric granite with megaphenocryst of cordierite, fine grained porfiric granite with megaphenocryst of cordierire and fine-medium granite. Los Berrocales is a zoned stock formed by granodiorites graded to granites in the center. Structure-studies indicates that the Campanario-La Haba pluton has been structurated in magmatic state. The magmatic foliation and lineation direction show the orientation ofN12ĂĽE, parallel to the pluton lenghtening. The magnetic susceptibility values show that the magnetic behaviour of the granites is dominated by paramagnetic minerals, fine for apply the Anisotropy ofthe Magnetic Susceptibility. The magnetic structure is rather homogeneous and the magnetic lineation and foliation show the N12ĂĽE direction. This paper shows premier dates and conclusions of the work that Mineralogy and Petrology department (University of Basque Country) has being done in conjunction with the Geodinamic department (University ofBasque Country) on the westhern end of the Los Pedroches Batholith

    The relationship between the plutonic intrusions and the dyke swarm in the Los Pedroches batholith (Iberian Massif, Spain): Dykes as a paleotectonic and paleostress indicators

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    [Abstract] The Los Pedroches batholith (Iberian Massif, SW Spain) is composed by a large biotite ±amphibole granodiorite pluton and several, smaller variable porphyritic, biotite ± cordierite granite intrusions. A dyke swarm composed esencially by trachyandesites, dacites and rhyolites cross cut the batholith. The whole set of plutonic and subvolcanic rocks define a K-rich, calc-alkaline alumino-cafemic association; only the trachyandesitic dykes ofshoshonitic affinity, get offthis trend. The dacitic and rhyolitic dykes are cogenetic with and probably comagmatic with thegranodioritic plutonand thegranitic intrusions, respectively. The trachyandesites, locallyshows sin-plutonic relations with thegranodiorite bodyand might becogenetic with mafic microgranular enclaves scattered through the granodiritic unit. The emplacement of the batholith and the dyke swarms is late-hercynian and postcollisional (300 Ma) and, was controled by a transtensional shear zone at acrustal scale. The dyke swarm use the tectonically generated fracture system during cooling and consolidation of the plutonic rocks: (i) R' type Riedel fractures for the trachyandesitic and dacitic dykes emplacement, and (ii) R type Riedel fractures for rhyolitic dykes emplacement. The arrangement ofsome dyke swarms can be use as a paleotectonic and paleostress indicators.

    Spatially explicit analysis reveals complex human genetic gradients in the Iberian Peninsula

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    The Iberian Peninsula is a well-delimited geographic region with a rich and complex human history. However, the causes of its genetic structure and past migratory dynamics are not yet fully understood. In order to shed light on them, here we evaluated the gene flow and genetic structure throughout the Iberian Peninsula with spatially explicit modelling applied to a georeferenced genetic dataset composed of genome-wide SNPs from 746 individuals belonging to 17 different regions of the Peninsula. We found contrasting patterns of genetic structure throughout Iberia. In particular, we identified strong patterns of genetic differentiation caused by relevant barriers to gene flow in northern regions and, on the other hand, a large genetic similarity in central and southern regions. In addition, our results showed a preferential north to south migratory dynamics and suggest a sex-biased dispersal in Mediterranean and southern regions. The estimated genetic patterns did not fit with the geographical relief of the Iberian landscape and they rather seem to follow political and linguistic territorial boundaries.IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). J.P. and A.M.L. are funded by the Portuguese Government through the FCT fellowship SFRH/BD/97200/2013 and the research contract IF/01262/2014, respectively. M.A. was supported by the “Ramón y Cajal” grant RYC-2015-18241 from the Spanish Government. D.C. was supported by the Spanish grant CGL2016-75389-P (AEI, MINEICO/FEDER, UE), and “Unidad María de Maeztu” funded by the MINECO (MDM-2014-0370)

    Changing eruptive styles and textural features from phreatomagmatic to strombolian activity of basaltic littoral cones: Los Erales cinder cone, Tenerife, Canary Islands

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    Montaña Los Erales is a 70 m high Quaternary cinder cone in the Bandas del Sur region, south Tenerife. Field observations on excavated sections and SEM analysis of tephra samples from the cone suggest that the eruption style of this vent changed progressively from an initial hydrovolcanic phase, through a transitional stage, to one that was entirely strombolian. Clast sizes increase from ≤1 cm angular lapilli in hydrovolcanic samples to 15 cm bombs in strombolian samples. Vesicles also increase in size from 0.5 mm to 1.2 mm, becoming more rounded in the strombolian samples. Palagonitization, extensive in the hydrovolcanic deposits, becomes less noticeable in strombolian deposits. To investigate the causes for and the nature of these changes in eruptive style, products from each major unit were analysed for their morphology, using scanning electron microscopy with both SE and BSE imaging as tephra morphologies are known to reflect the eruptive regime and degree of explosivity at the time of eruption. SEM imaging of hydrovolcanic samples illustrate angular fragments that have been rapidly quenched and contain high levels of palagonitisation and zeolitisation, whereas strombolian samples appear to be less altered and display larger clast sizes and vesicles. Our results confirm that the initial phase of activity was largely driven by magma-water (coolant) interaction, where magma may have interacted with a lens of fresh ground or surface water, causing intense fragmentation of the magma. With proceeding eruptive activity the water became exhausted, giving rise to an entirely strombolian eruptive style. Additionally, fossil diatoms were found in hydrovolcanic samples, further emphasising the influence of a, probably fluvial, water source during the early phase of emplacement.La Montaña de Los Erales es un cono de cínder del Cuaternario de 70 m de altura situado en la zona de las Bandas del Sur, en el litoral meridional de la isla de Tenerife. Observaciones de campo en secciones excavadas en los flancos del cono y análisis SEM de las muestras de tefra sugieren que el estilo eruptivo de este aparato volcánico cambió progresivamente durante la erupción de una fase inicial hidrovolcánica a una final enteramente estromboliana, con estadios intermedios transicionales. El tamaño de los clastos aumenta de ≤1 cm de lapilli angular en las muestras hidrovolcánicas a bombas de 15 cm en las estrombolianas. Las vesículas también aumentan en tamaño desde 0,5 mm a 1,2 mm, volviéndose más redondeadas en las muestras estrombolianas. Los intensos procesos de palagonitización de los depósitos hidrovolcánicos son menos significativos en las fases estrombolianas. Con objeto de investigar la naturaleza y las causas de estos cambios se analizó la morfología de los productos de las principales fases. Se han utilizado para ello imágenes de microscopía electrónica (SE y BSE), ya que se sabe que las diferentes morfologías de estos piroclastos reflejan el régimen eruptivo y el grado de explosividad durante la erupción. Las imágenes SEM de las muestras hidrovolcánicas presentan fragmentos angulares que se han enfriado rápidamente y con elevado grado de palagonitización y zeolitización. Las estrombolianas, en cambio, aparecen menos alteradas y muestran mayor tamaño de clastos y vesículas. Los resultados obtenidos indican que la fase inicial de la erupción se caracteriza por una importante interacción magma-agua (refrigerante), probablemente relacionada con una cantidad limitada de agua superficial o freática que produjo la intensa fragmentación del magma. En el transcurso de la erupción la fuente de agua se agotó, dando lugar a las fases finales de carácter enteramente estromboliano. Fósiles de diatomeas, que se han encontrado asociados a las muestras hidrovolcánicas, refuerzan la posibilidad de que el agua fuera de origen superficial, probablemente el cauce de un barranco

    The Linares granite (Jaén): cartography, petrology and geochemistry

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    [Abstract] Magma emplacement within the Linares granite, a part of the Los Pedroches Batholith, took place in the sequence: biotite granodiorite with microgranular enclaves, biotite monzogranites, and dike swarm complexo Dikes are: WNWESE rhyolite to rhyodacite, aplopegmatite and abundant NE-SW ore-bearing quartz. The Linares intrusion and psamo-pelitic Carboniferous host metasediments (Los Pedroches Culm) are, in part, discordantly covered by Mesozoic (Trias) and Tertiary to Quaternary terrigenous deposits. Bulk rock chemistry of granodiorite shows minor variations in Si02 (64.75... 67 wt %) and REE contents (LREE = 158 -160 ppm), and nearly constant Al CNK (ISA) ratio (1.1 - 1.15). Monzogranites have higher Si02 (66.87 - 68.4 wt %), alkali and REE contents (LREE = 168 - 193 ppm), with A/CNK (ISA) ratio of 1.06 - 1.09. Both granodiorite and monzogranites are peraluminous rocks that may correspond to an aluminous association or to evolved terms of an aluminocafemic association (Debon & Lefort, 1983). Variation diagrams for major and trace elements, including REE, of granodiorite and monzogranites are compatible with magmatic differentiation processes by fractional crystallization starting from a primary granodioritic magma
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