Geogaceta -- Nº 09, (1990)
Permanent URI for this collectionhttps://hdl.handle.net/10272/14919
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Item type: Item , Vegetación y clima holocenos en el puerto de la Morcuera (Madrid) en base a datos polínicos(Sociedad Geológica de España, 1990) Gil García, María José; Ruiz Zapata, BlancaIt is presented the first palynologycal data obtained in one peat of de la Morcuera (Madrid). The study of this area will give us a best palynologycal knowledge, in the most eastern part of the Sistema Central and show us the evolution and development of the vegetation in this zoneItem type: Item , Una importante discontinuidad estratigráfica del Paleoceno de Navarra y del País Vasco: caracterización y significado(Sociedad Geológica de España, 1990) Robador, Alejandro; Pujalte, Victoriano; Orue Etxebarria, Xabier; Baceta, Juan Ignacio; Robles, SantiagoAn important stratigraphic break has been recognized in the Paleocene of Navarra and the Basque Country, which is recorded with different features, both in platform and basinal settings. lt has been correlated through paleontological dating, with the major sea-level drop of the Paleocene and is therefore ascribed to eustasy. In many instances, this break is responsible for informal lithostratigraphic subdivisions of these sediments advanced by previous authorsItem type: Item , Superficies de erosión y tectónica neógena en el extremo occidental del Sistema Central español(Sociedad Geológica de España, 1990) Moreno Serrano, F.Paleogene erosion surface (S1), with plioquaternary retoruching (S1-D), is unleveled and tilted in diferent blocks. Main movements occured in Iberica stage or Castallana phase (Upper Oligocene - Lower Miocene) and Guadarrama stage or Neocastellana and Iower Tortanian phases (Iower to middle Miocene). Neocastellana phase probably was the most important of them and reactivated as thrusts former normal faults, striking NE-SO to ENE-OSOItem type: Item , Significado de la ruptura entre las Unidades Tectosedimentarias N2 y N3 en el centro de la Cuenca del Ebro(Sociedad Geológica de España, 1990) Arenas Abad, Concepción; Pardo, GonzaloIn the Alcubierre Sierra, the sedimentary break between the Tectosedimentary Units N2 (middle and upper Aragonian) and N3 (upper Aragonian-Val/esian) represents an important paleogeographic change, related to the diastrophic activity in the northern margin of the Ebro Basin: the expansive lacustrine sedimentation of the TSU N2 is clearly replaced by alluvial deposits of the TSU N3. This boundary implies a period of subaerial exposition with erosion. A tectonic instability phase in relation to this boundary is shown by a North-South synsedimentary fault system, and small structures such as cracks an slumpsItem type: Item , Significado de los cuerpos de leucogranitos y de los «gneises cordieríticos con litoclastos» asociados en la Unidad de Guadiaza (Alpujárrides occidentales, Béticas)(Sociedad Geológica de España, 1990) Muñoz, MercedesThe relationships and significant petrological features of the rock succession in the Guadaiza Unit are described. According to these data, the «cordierite gneisses with lithoclasts» appear as an extensional tectonic breccia, which results from a Iow T mylonitic deformation event subsequent to LP-HT alpine regional metamorphism. Simultaneous to this extensional event, the emplacement of intrusives type leucogranite bodies occurs. These bodies cause contact metamorphism and contamination phenomena in the host brecciated rocks, configurating their present textural and compositional featuresItem type: Item , Sedimentología de la formación Miers Bluff en los alrededores de la Base Antártica española. Isla Livingston. Shetland del Sur(Sociedad Geológica de España, 1990) Arche, A.; López Martínez, Jerónimo; Martínez de Pisón, E.The Miers Bluff Formation crops out in the Hurd Peninsula, Livingston Island. lt consist of greywackes and slates, organised in coarsening-thickening and fining-thinning cycles. They have been interpreted as channelised and non-channelised turbidites from a mid- and outer turbiditic fanItem type: Item , Sedimentación lacustre finicretácica en el Prebético de Murcia: caracterización estratigráfica(Sociedad Geológica de España, 1990) Martín Chivelet, JavierTwo formations, corresponding respectively to the Iower Campanian-upper Maastrichtian and the uppermost Maastrichtian-PaIeocene depositional sequences, are recognized in the outer areas of the Prebetic setting and characterized by the installation of lacustrine systems during the uppermost CretaceousItem type: Item , Rocas volcánicas submarinas en la base de la Formación Cañadas. Macizo de Tigaiga (N. de Tenerife)(Sociedad Geológica de España, 1990) Ibarrola, E.; Fúster, J. M.; Ancochea, Eumenio; Huertas, María JoséA volcanic submarine formation crops out in the north coast of Tenerife, east of San Juan de la Rambla. This unit is formed by massive and pillowed lavas, pillow-breccias, hyaloclastites and palagonitic tuffs and is interpreted as consisting of subaerial lavas that flowed into shallow marine waters. The lavas are amphibolic trachybasalts. An unaltered sample coming from the most massive zone has yielded a whole rock 2.60±0.17 Ma K-Ar age. These submarine lavas are underlying the oldest formations of the Las Cañadas Series dated at 1.24 Ma in that same area. The submarine lavas correspond to a time period for which very scarce information was yet available in TenerifeItem type: Item , Restos de carbón en el Cretácico inferior del Subbético medio (Cordillera Bética)(Sociedad Geológica de España, 1990) Hernández, F. J.; Aguado, RoqueSignificant quantities of coal remains have been found in the Lower Cretaceous deposits of the southernmost Middle Subbetic (Montes Orientales, Betic Cordillera). The pelagic sedimentary environment of these deposits was isolated from significant continental influx. The coal source may have been the Iberian Meseta, reaching these remote areas as a result of a combination of hydrodynamic factors together with paleoceanographic patterns of the Cretaceous basin.Item type: Item , Reactivación de la falla de Alhama de Murcia (sector de Lorca-Totana): cinemática y campos de esfuerzos desde el Messiniense hasta la actualidad(Sociedad Geológica de España, 1990) Martínez Díaz, J. J.; Hernández Enrile, J. L.In this work we analyze the kinematics of the Alhama de Murcia fault and other fracturation systems in the area of Lorca-Totana. An alternance of NW-SE to NNE-SSW shortening directions can be identified from the Messinian to the present. This seems to be a consequence of intermittent activity along the Palomares fault (NNE-SSW), inducing changes in the trajectories of the NW-SE directed regional stress field.Item type: Item , Pulsaciones glaciares y terrazas marinas escalonadas en los alrededores de la Base Antártica Española. Isla Livingston. Shetland del Sur(Sociedad Geológica de España, 1990) López Martínez, Jerónimo; Martínez de Pisón, E.; Arche, A.The recent fluctuations of the glaciers can be modellised near the Antarctic Spanish Base (BAE), where Six morainic arches are exposed, as well as eight marine terraces up to +18.6 m. Some conclusions about the recent evolution of the island can be drawn from the geomorphological maps and profiles elaboratedItem type: Item , Nuevas precisiones sobre los depósitos de sulfatos de los alrededores de Gijón (Asturias)(Sociedad Geológica de España, 1990) Manjón, M.; Gutiérrez Claverol, M.A borehole drilled in the only gypsum mine of Asturias has shown the existence of anhydrite and gypsum at depths greater than presently exploited. These stratiform deposits were laid down in distal flood plains, tidal flats an sabkha environmentsItem type: Item , Minerales accesorios en el monzogranito de Las Navas del Marqués (Sistema Central Español)(Sociedad Geológica de España, 1990) Brändle, José Luis; Casillas, R.; Forizs, I.; Panto, G.; Peinado, M.El objeto de este trabajo es el estudio de los minerales accesorios en el monzogranito de Las Navas del Marqués. Se discuten en detalle, no sólo sus características descriptivas sino también las genéticas. Las variaciones de composición observadas son un precioso instrumento para el estudio de la génesis de las rocas graníticas; así, la fraccionación de algunos elementos durante la diferenciación puede ser cotnrolada mediante las zonaciones de los minerales accesoriosItem type: Item , Los macizos ultramáficos de Sierra de las Aguas y Sierra de la Robla como una ventana extensional (Béticas occidentales)(Sociedad Geológica de España, 1990) Soto, Juan I.; Gervilla, FernandoIn the northernmost outcrops of ultramafic rocks of the Nappe de Los Reales (Sierras de las Aguas y de la Robla) it has been analysed the distribution of mineral facies and the minor structures associated to extensional faults. A detachment zone is located between the Nappe de los Reales and the Malaguide Complex with some movement along the basal contact of the Alozaina Complex. The minor structures associated to extensional faults indicates a sense of shear towards the SSWSSEItem type: Item , Los índices internacionales de evaluación. Su aplicación a la investigación geológica española(Sociedad Geológica de España, 1990) López Ruiz, JoséItem type: Item , Las secuencias deposicionales del Eoceno medio y superior de las Sierras exteriores (Prepirineo meridional aragonés)(Sociedad Geológica de España, 1990) Canudo, José Ignacio; Malagón, J.; Meléndez Hevia, Alfonso; Millán Garrido, H.; Molina, Eustoquio; Navarro, J. J.The middle and upper Eocene marine sediments in the Sierras exteriores (Prepyrenees) are studied. Several depositional sequences are recognized: Calizas de Guara Formation (SD1, SD2 and SD3), Margas de Arguis Formation (SD4, SD5 and lower part of SD6) and Belsue-Atares Formation (SD6). Tentatively these sequences are correlated with the eustatic global cycles and their tectonic influence are analizedItem type: Item , Las facies de cursos entrelazados en el Pleistoceno de Isla Cristina (Huelva)(Sociedad Geológica de España, 1990) Romero Segura, Mª J.; Pendón Martín, José GabrielVarious facies sequences generated in a fluvial regime of braided type are identified in a series attributed to the Pleistocene from Southwestern Huelva (Southwestern Spain). Channel and bar facies are mainly represented. These data allow to extend to the west the same conclusion that have been pointed out in another relationed sectorItem type: Item , La macroflora del Keuper en la zona Subbética y su relación con las facies sedimentológicas para una interpretación paleoambiental(Sociedad Geológica de España, 1990) Pérez López, Alberto; Alvarez Ramis, C.It has been found rests of plants in the Keuper facies in the central sector of Betic Cordillera. There are rests of autochthonous plants (Equisetitês arenaceus (Jaeger) Brongn) in sandstones and siltstones, related to coast and wet zones; rests of cycadophytes sometimes associated with ferns, possibly placed in a steppe plain; and rests of conifers, that have suffered a long transport, related to the sandstones of an ephemeral fluvial system. lt has been possible to determine the interest of a paleoecological study supported by sedimentological dataItem type: Item , La Caliza de Peña Redonda (Westfaliense A-B): Evolución tecto-sedimentaria (Cuenca Carbonífera Central asturiana)(Sociedad Geológica de España, 1990) Salvador, C. I.The occurrence of destructive carbonatic facies at the top of a tectonically controlled megasequence and his probable widespread distribution may be an indicator of an extensive emersion during Westfalian A-B boundary, and could hide important changes in the local fossil distributionItem type: Item , Introducción al estudio de los indicios cupríferos de Riner y de Clariana (Depresión geológica del Ebro, Solsonés, Cataluña)(Sociedad Geológica de España, 1990) Mata Perelló, Josep MariaThe present work has developed about three indications of Cu, localised in the region of Solonés, in the localities of Riner and Clariana. The three cases are situated among the materials of Formation Solsona, which refill in some part the Ebro Geological Depression, in the area corresponding to the Central Depression. This formation has predominant detritus character, and part of it is formed by fluvial deposits. In all the cases, it is about mineralisations the kind of stratabound, formed by the resultant of a precipitation of Cu as sulphide, in reducter ambients, transported by continental waters in form de soluble sulphate, and afterwards oxidized to malachite