Geogaceta -- Nº 06, (1989)
Permanent URI for this collectionhttps://hdl.handle.net/10272/18208
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Item type: Item , ô 180 of granites from the Western Central Iberian Massif, Spain(Sociedad Geológica de España, 1989) Ugidos, José María; Fallick, A. E.; Recio, ClementeSe han determinado las relaciones isotópicas de oxígeno de varios tipos de granitos y migmatitas (nebulitas cordieríticas) en sectores occidentales del Macizo Central español. Granitos biotíticos y biotítico-anfibólicos muestran valores de ð18O entre 9 y 10,50/00 (SMOW). Las nebulitas muestran una mayor variación (10-130/00). Los granitos con cordierita tienen valores intermedios (entre 9,8 y 10,50/00), sugiriendo la posibilidad de ser el resultado de la asimilación de nebulitas por el magma que origina los granitos biotíticosItem type: Item , Sedimentación lacustre fanerozoica en España(Sociedad Geológica de España, 1989) Meléndez Hevia, Alfonso; Meléndez Hevía, NievesItem type: Item , Sedimentación continental miocena entre San Esteban de Gormaz y el Burgo de Osma (Soria)(Sociedad Geológica de España, 1989) Ràmos Martín, M. C.; Alonso Gavilán, G.; Armenteros, IldefonsoThe main of this paper is to describe two units litostratigraphic deposits within miocene formations of the SE Duero Basin. The sediments developed in alluvial fan and palustrine areas display some variety resulting from sustrate nature, composition of source area, climatics and water hostingItem type: Item , Relleno de canales abandonados en la Formación Areniscas de Cabrerizos (Eoceno, Salamanca)(Sociedad Geológica de España, 1989) Alonso Gavilán, G.Two models of the channels fills deposits we are identified in the Cabrerizos Sandstone Formation (Eoceno), A): Channel fill associated a slowly abandoned of the system and rapid infilling next active channels and B): channel fill associated a swift abandoned and slowly infilling far a active channelsItem type: Item , Reflejo de la estratigrafía secuencial del Eoceno inferior surpirenaico en una parte de la sección de Campo(Sociedad Geológica de España, 1989) Remacha Grau, Eduard; Zamorano, M.Four depositional sequences (SE-I, SE-2, SE-3 and SE-4) have been recognized in the Iowermost Eocene of the south-central Pyrenees. These correspond to the previous Figols sequence of Mutti et al. (1985). SE-2 and SE-4 are type 1 sequences (in the sense of Vail et al. 1984), whereas SE-3 is a type 2 sequence. There is a clear correlation between these sequences and the third order global cycles defined by Haq et al. (1987)Item type: Item , Plancton y bentos calcáreos del Neógeno superior en sondeos oceánicos (D.S,D.P.) del Atlántico NE y sistema Bético-rifeño(Sociedad Geológica de España, 1989) Flores, José Abel; Sierro, Francisco Javier; Civis-Llovera, Jorge; Francés, Guillermo; Valle, M. F.; González Delgado, José ÁngelIn this report we summarize the main results obtained on the calcareous plankton and benthos of the North Atlantic and Betic-riffean system. A scheme showing the most important changes in the planktonic foraminiferal and calcareous nannoplankton assemb/ages is presented. These changes have been correlated with the chronostratigraphic and magnetostratigraphic scales, according to the study of Berggren et al. (1985). With respect to the Benthic Foraminifera, two main assemblages have been found, wich are related to different paleoceanographic conditions in the Deep North Atlantic OceanItem type: Item , Neotectónica en la cuenca del alto Tormes (Sistema Central, Avila): Influencia en la morfología fluvial(Sociedad Geológica de España, 1989) Pol, C.; Sánchez del Corral, A.; Carballeira, J.The High Tormes is caracterized for its aluvial and torrential regimen who ask to a general model of sinuous river complex: straight segments, straight with lateral bars, braided and meandering. The presence of gradient index anomalous high permits to deduce the existence of tectonic activity who falls in the river's patter. The study of relict's boulders bars permits to deduce the structural condicionament of its deposits and the existence of a neotectonics in this section of the Central System after its origenItem type: Item , Moluscos, Ostrácodos y Palinología de las facies fluvio-lacustres del Neógeno del SE de la provincia de Valladolid (Cuenca del Duero)(Sociedad Geológica de España, 1989) Civis-Llovera, Jorge; Armenteros, Ildefonso; Valle, M. F.; González Delgado, José Ángel; Rivas Carballo, María Rosario; Sierro, Francisco Javier; Flores, José AbelThe Mollusca, Ostracoda, Foraminifera and Palino/gy from 14 localities in the Eastern Neogene of Valladolid (Duero Basin) are studied. Differents stratigraphic levels are included in the Facies «Dueñas», «Zaratán», «Cuestas» and «Caliza de los Páramos» units. The Mollusca are found in the lacustrine facies and are essentially dominated by Gyraulus. The qualitative and quantitative analysis of Ostracoda-Foraminifera associations are indicative of paleosalinities; increase in salinity is pointed by Candonidae-llyocypris, llyocypris-Cyprinotus, Cyprinotus-Cyprideis- Foraminifera, successively. In general, the samples are poore in palinomorphs and richev in microalgal componentsItem type: Item , Modalidades del emplazamiento de intrusiones calco-alcalinas, Stephaniense-Pérmicas, en el sector norte del Anticlinal de Montalbán (provincia de Teruel)(Sociedad Geológica de España, 1989) Torres, J. A.; Lago, J.; Pocoví Juan, AndrésIn Montalban Anticline North Zone (Paleozoic basement of the Iberian Chain) a magmatism with calc-alkaline affinity, characterized by numerous Stephanian-Permian hypovolcanic intrusions, wich intruded in both carboniferous and devonian sediments, is well represented. Some examples about the intrusions emplacement forms as well as a preliminary analysis of the country rock structure are shownItem type: Item , Mineralogía y texturas del meteorito de Nulles (colección del M.N.C.N., Madrid)(Sociedad Geológica de España, 1989) Martínez Frías, J.; Rodríguez, J. A.; Benito García, R.; García Guinea, JavierThe mineralogical and textural features of the Nulles meteorite are studied by optical microscopy, SEM, and electrone microprobe. Olivine and plagioclase are the main primary phases of the silicate minerals, with the subsequent formation of epidote, from the oligoclase. The metallic phase consists of kamacite, taenite and troilite, with variable proportions of their Fe and Ni contents. The main textures reflect, apart of deformation, the existence of chondrules, intergrowths and seudomorphismsItem type: Item , Major Pleistocene and Holocene glacial episodes in the Khumbu region, southern side of Mount Everest (Nepalese Himalaya)(Sociedad Geológica de España, 1989) Martínez de Pisón, E.; López Martínez, JerónimoSe amplía hacia la vertiente meridional del Everest la cartografía de la geomorfología glaciar realizada anteriormente por los autores en el sector tibetano de este macizo. Se distinguen cuatro fases glaciares principales desde el Pleistoceno a la Pequeña Edad del Hielo, con frentes morrénicos situados a las siguientes altitudes: 2.400 m, 4.330 m, 4.600 m, Y 4.926 m.Item type: Item , Los pliegues tumbados del Manto de Lújar y su modificación por el sistema de cabalgamientos frágiles (complejo Alpujárride, Cordillera Bética)(Sociedad Geológica de España, 1989) Campos, J.; Simancas Cabrera, J. F.The Alpujárride Complex results from a complicated structural evolution, party synmetamorphic, with different kinematic vectors. In this note we focus on the postmetamorphic structure in the Iower Alpujárride Nappe, which include recumbent folding and thrusting to the north. New geometric and kinematic aspects are pointed outItem type: Item , Los micromamíferos del Mioceno inferior de Pañalba (Huesca). Implicaciones bioestratigráficas(Sociedad Geológica de España, 1989) Cuenca Bescós, G.; Azanza, Beatriz; Canudo, José Ignacio; Fuertes, V.The Lower Miocene deposits of the Peñalba area in the Ebro basin, have yielded mammalian remains at various levels. New mammalian remains are studied in this paper. The new paleontological data offers the possibility to discuss the Lower Miocene biozonations in this areaItem type: Item , La transgresión Ilerdense (calizas de Alveolinas) en la Cuenca de Villarcayo (Burgos)(Sociedad Geológica de España, 1989) Montes Santiago, M. J.; Alonso Gavilán, G.; Dabrio, Cristino JoséThe Villarcayo basin is situated at the NW of Duero Basin and it's incorporated into the Cantabric dominio. The ilerdien transgression is represented for Alveolina Limestone inconformity above transition marine-continental lower deposits Litoral detritic deposits are situated above this limestone unit and they constitue a new regresive episodeItem type: Item , Las secuencias deposicionales del Eoceno del Prepirineo Oriental(Sociedad Geológica de España, 1989) Costa Mercadal, J. M.; Maestro Maideu, E.Several depositional sequences have been distinguished in the Eocene of the eastern Pyrenees in the sense of Mitchum et al. (1977). A general scheme of the basin is shown in figure 2. Eocene sediments and erosive unconformities between them are represented in this figure. We point out that the material forming the base of the sequences is resedimentated from the underlying sequences, giving olisthostromic bodies, carbonate megaturbidites or siliciclastic turbiditesItem type: Item , Las rocas ígneas de Estalaya (Palencia) y los Skarns asociados(Sociedad Geológica de España, 1989) González Montero, M. P.; Corretgé Castañón, Luis Guillermo; Suárez Hernando, OierIn this paper we make a brief study of the intrusive rocks from the Estalaya stock (Palencia, Spain), with special regard to the alteration processes. We also present a short description of the calc-silicate rocks of the associated skarnItem type: Item , Las relaciones Pb-Zn en las rocas carbonatadas del Cretácico Inferior del Noroeste de Cantabria (España)(Sociedad Geológica de España, 1989) Bravo, J. I.Pb-Zn relationships of 576 samples in ppm have been studied in the present paper in order to observe the possible conections of those elements in the enviroment of the mineralizations which all fit into the iron-rich dolomites of the Lower Cretaceous, thus being able to define favourable characteristics on a regional scale which Will provide relevant prospection data for the preparation of their genetic modelItem type: Item , La estructura del plutón granítico de Boal (Asturias, España): Nuevas aportaciones sobre su «fabric» interna y modo de emplazamiento(Sociedad Geológica de España, 1989) Fernández Suárez, Javier; Corretgé Castañón, Luis Guillermo; Suárez Hernando, OierIn this paper we attempt to sketch the structural pattern of the Boal pluton (WestAsturian-Leonese Zone) and provide new data which account for a pasive mode of emplacement and a subsequent structural evolution probably controled by a vertical NNE-SSW dextral shear zone which postdates the three main regional deformation phasesItem type: Item , La arenisca de Villamayor: Influencia de la humedad en su resistencia(Sociedad Geológica de España, 1989) Megías, J. M.; Madruga, F.; Fernández Calvo, C.Villamayor sandstone is the main ancient and modern building material in Salamanca. The results of the tests relates the failure strength with the moisture content and the strainItem type: Item , Influencia del paleokarst en la mineralogía de arcillas del Lias de Algarinejo (Subbético medio)(Sociedad Geológica de España, 1989) Vera, J. A.; Palomo, J.; Ortega Huertas, M.A clear relationship exists between the kaolinite content of the mid-Domerian to mid-Toarcian rocks of the Algarinejo section and the emersion at the same time of the Loma de las Ventanas section some 10 km away. A model is proposed for the evolution of the palaeogeography where karstification and pedogenetic processes took place on islands within the passive continental margin, which in turn influenced the clay-mineral composition of the nearby pelagic deposits