541 research outputs found

    MAGSAT anomaly map and continental drift

    Get PDF
    Anomaly maps of high quality are needed to display unambiguously the so called long wave length anomalies. The anomalies were analyzed in terms of continental drift and the nature of their sources is discussed. The map presented confirms the thinness of the oceanic magnetized layer. Continental magnetic anomalies are characterized by elongated structures generally of east-west trend. Paleomagnetic reconstruction shows that the anomalies found in India, Australia, and Antarctic exhibit a fair consistency with the African anomalies. It is also shown that anomalies are locked under the continents and have a fixed geometry

    Management System for Harvest Scheduling: The Case of Horticultural Production in Southeast Spain

    Get PDF
    horticultural farmer, optimization, planning, mathematical programming, marketing, cooperative, Agribusiness, Crop Production/Industries, Demand and Price Analysis, Farm Management, Land Economics/Use,

    El Torcal de Antequera, un ejemplo de estructura formada por un importante sistema transcurrente dextrorso

    Get PDF
    The Torcal de Antequera is situated in the Penibetic (part of the Betic External Zone) very near of the contact with the Internal Zone. It has an E-W fusiform shape and corresponds to a monocline structure, surrounded and uplifted by large scale dextral strike-slip faults. Its interior includes a large number of map-scale fractures, most of which can be explained by a mega dextral shear system. The minor structures measured, linked to the faults, are also consistent with this shear system and with its progressive evolution. The deduced predominant direction of s1 is NW-SE, congruent with the oblique displacements occurred between the Internal Zone and the Penibetic in this area; the Torcal area is one of the megastructures formed by it.El Torcal de Antequera está situado en el Penibético (parte de la Zona Externa Bética) cercano a la Zona Interna. Tiene una forma ahusada en la dirección E-O y corresponde a una estructura monoclinal, rodeada y levantada por grandes fallas de desgarre dextrorsas. En su interior existen innumerables fallas, la mayoría de las cuales pueden explicarse dentro de un sistema de desgarre dextrorso a gran escala. Las estructuras menores medidas, ligadas a las fallas, son consistentes con este sistema de cizalla y con su progresiva evolución. La dirección predominante de s1 deducida es NO-SE. En esta área, el sistema de cizalla está ligado a los desplazamientos de la Zona Interna en relación con el Penibético; el área del Torcal corresponde a una de las megaestructuras formadas en él

    Preliminary models of the core field

    Get PDF
    Using the CHROFIN tapes containing MAGSAT data for the month of December, two spherical harmonic models were prepared. One of these models was specially designed to study the Bangui anomaly region. For this region an attempt was made to downward continue the data and to compare it with the existing ground level map

    Gravity anomalies and orthogonal box fold development on heterogeneous basement in the Neogene Ronda Depression (Western Betic Cordillera)

    Get PDF
    28 páginas, 6 figuras.-- PDF es el manucristo aceptado del autor (post-print).The Ronda Depression constitutes a Neogene intramontane basin located in the external zones of the Western Betic Cordillera. Major deformation structures affect only the southwestern part of its sedimentary infill and consist of NNE–SSW and WNW–ESE box folds that developed simultaneously. New gravity data reveal two negative NNE–SSW elongated Bouguer anomalies, unrelated to basin depocenters, but corresponding to the accumulation of low-density ductile Triassic basement rocks in the core of antiforms or directly under the northwestern undeformed sedimentary infill. The Subbetic basement is also deformed by early-Burdigalian to Serravallian NNE–SSW folds and thrusts, although there is no clear continuity with those affecting the late-Miocene sedimentary infill. The aim of this contribution is to describe in detail the late-Miocene folds that deform the Ronda Depression, as well as to discuss the role of the basement nature on their reactivation. The reactivation of the pre-Tortonian folds, due to the heterogeneous distribution of evaporitic Triassic rocks in the basement as well as the presence of rigid limestones on the southwestern basin boundary, determined the simultaneous orthogonal fold development that only evidence local deformation.This study was supported by a PhD grant to the first author from Spain´s Ministerio de Educación y Ciencia and the projects CSD2006-00041 and CGL 2006-06001 (MEC) and Junta de Andalucía.Peer reviewe

    Strike-slip faults in the south Haouz (Calcareous Dorsal, Internal Rif, N of Tetouan, Maroc). Comparison with the Betics (Spain)

    Get PDF
    4 páginas, 4 figuras.-- Trabajo presentado en la 41ª Sesión Científica, Barcelona, 2006.Different sets of strike-slip faults of the Haouz Mountains (from Tetouan to the strait of Gibraltar) deform the tectonic slices of the Calcareous Dorsal there present. In this paper we study those faults at the southern part of the Haouz. Three fault formation stages can be distinguished and correspond to the progressive s1 rotation during the Neogene from a near E-W position to approximately N-S, in a progressive anticlockwise rotation. The faults and other related structures are compared with similar ones existing in the Betic Cordillera, in equivalent areas of the arc of Gibraltar.Este artículo es una contribución del grupo de Travaux de Recherches de l’Unité Risques Géologiques et Télédetection, 2006, Rabat y de los proyectos BTE2001-5230-E, CGL200401636/BTE, CGL2004-03333/ BTE, y el grupo RNM 217 de la Junta de Andalucía.Peer reviewe

    A strike-slip fault corridor within the Alpujarra Mountains (Betic Cordilleras, Spain)

    Get PDF
    15 páginas, 6 figuras.[EN] In a long »corridor« in the internal zone of the Betic Cordilleras, bounded to the north by the Sierra Nevada and to the south by the Sierras Lujar, Contraviesa and Gador, two discernible bands of strike-slip faults exist: These bands lie in an approximately E-W direction and are well exposed throughout and beyond the 85 km long belt. The characteristic features of strike-slip faults, such as cataclastic rocks composed of variously textured fault breccia, which also include fragments of rocks up to several metres in size, incipient foliation, and striation demonstrate the right-lateral nature of the displacement. There are also fractures which run in a NW-SE and NNE-SSW direction, and apparently originated after formation of the E-W faults. The magnitude of lateral displacements is difficult to calculate. Evidence of considerable vertical movement can be found locally. These strike-slip displacements have essentially occurred since the middle Miocene period and might still be taking place.[AL] In einem langen Korridor in der Internzone der Betischen Kordilleren, der im Norden durch die Sierra Nevada und im Süden von den Sierren Lujar, Contraviesa und Gador begrenzt wird, sind zwei Streifen mit Blattverschiebungen zu beobachten. Sie streichen etwa E-W und sind gut entlang des 85-km-langen Gürtels aufgeschlossen. Die charakteristischen Merkmale von Blattverschiebungen wie etwa kataklastische Gesteine mit verschiedenen texturierten Verwerfungsbrekzien, welche auch bis zu mehreren Metern große Gesteinsblöcke enthalten, beginnende Schieferung und Harnischbildung, zeigen die dextrale Natur der Bewegung. Daneben treten NW-SE und NNE-SSW streichende Störungen auf, die offensichtlich nach der Bildung der E-W verlaufenden Blattverschiebungen entstanden sind. Das Ausmaß des lateralen Versatzes ist schwer abzuschätzen. Diese Bewegungen finden seit dem mittleren Miozän statt und sind möglicherweise immer noch aktiv.[FR] Dans un long couloir situé dans la zone interne des Chaînes Bétiques et limité au Nord par la Sierra Névada et au Sud par les Sierras de Lujar, Contraviesa et Gador, s'observent deux trains de failles de décrochements. Ces trains ont une direction à peu près E-W et sont bien exposés tout au long des 85 Km de cette zone. Les traits caractéristiques des décrochements, tels que cataclasites, brèche de faille avec fragments de roches jusqu'à plusieurs mètres de longueur, schistosité naissante et striation, démontrent la nature dextre du déplacement. Il existe aussi des fractures de direction NW-SE et NNW-SSW qui se sont vraisemblablement formées postérieurement aux failles E-W. La valeur du déplacement latéral est difficile à estimer. On rèléve localement des indices de mouvements verticaux importants. Ces décrochements se sont produits essentiellement à partir du Miocène moyen et peuvent encore se poursuivre aujourd'hui.This study was carried out under the auspices of the Departamento de Investigaciones Geológicas del C.S.I.C., Centro Coordinado con la Universidad de Granada, during a research project entitled: "Borde mediterráneo español: Evolución del Orógeno Bético y Geodinámica de las Depresiones Neógenas".Peer reviewe

    Influence of thickness on properties of plasticized oat starch films.

    Get PDF
    The aim of this study was to investigate the effect of thickness (between 80 and 120 µm) on apparent opacity, water vapor permeability and mechanical properties (tensile and puncture) of oat starch films plasticized with glycerol, sorbitol, glycerol:sorbitol mixture, urea and sucrose. Films were stored under 11, 57, 76 and 90% relative humidity (RH) to study the mechanical properties. It was observed that the higher the thickness, the higher was the opacity values. Films without the plasticizer were more opaque in comparison with the plasticized ones. Glycerol:sorbitol films presented increased elongation with increasing thickness at all RH. Puncture force showed a strong dependence on the film thickness, except for the films plasticized with sucrose. In general, thickness did not affect the water permeability

    Evidence for the activity and paleoseismicity of the Padul fault (Betic Cordillera, southern Spain)

    Get PDF
    There is evidence of recent tectonic activity in the proximity of Padul, in the central sector of the Betic Cordillera. The principal active fault in this region is the Padul normal fault, running NW-SE, which displays spectacular geomorphological and structural features owing to its recent activity. However, there is no evidence of earthquakes of moderate-high magnitude occurring in this area during the historical or the instrumental period. In the vicinity of Padul we identified various soft-sediment deformation structures produced by liquefaction which we attributed to seismic shocks of a moderate-high magnitude. These structures are situated in detritic sediments, intercalated with layers of peat, which have enabled dating of these paleoearthquakes to the late Pleistocene (approx. 30,000 to 35,000 yr BP). Moreover, field observations in sediments of alluvial fans in the vicinity of the Padul fault, together with a retrodeformation analysis of an outcrop, enabled various deformation events to be dated to the recent Quaternary period.En el área de Padul, localizada en el sector central de la Cordillera Bética, existen numerosas evidencias de actividad tectónica reciente. La principal falla activa de la región es la falla normal de Padul, de dirección NW-SE, que presenta evidencias geomorfológicas y estructurales espectaculares de su actividad reciente. Sin embargo, no se tiene constancia de la ocurrencia de terremotos de magnitud moderada-alta en el área de Padul ni durante el periodo histórico ni el instrumental. En este sector hemos identificado varias estructuras sedimentarias de deformación producidas por licuefacción que interpretamos como resultado de sacudidas sísmicas de magnitud moderada-alta. Estas estructuras se localizan en sedimentos detríticos intercalados con niveles de turba que han permitido datar estos paleoterremotos como Pleistoceno superior (aproximadamente entre 30.000 y 35.000 años B.P.). Por otra parte, las observaciones de campo realizadas en algunos sedimentos de los abanicos aluviales de la zona de falla de Padul y el análisis de retrodeformación en un afloramiento han permitido identificar varios eventos de deformación durante el Cuaternario reciente
    corecore