Geogaceta -- Nº 02, (1987)
Permanent URI for this collectionhttps://hdl.handle.net/10272/18212
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Item type: Item , Sobre la posición sistemática de los ammonites del Oxfordiense de los Andes Chilenos (Cordillera Domeyko, Chile, Provincia Andina)(Sociedad Geológica de España, 1987) Meléndez Hevia, Guillermo; Myczynski, R.The study of Oxfordian Perisphinctidae (Ammonoidea) from the Andean Province (Chili) shows a marked Iow share of typically european representatives (Perisphinctinae), the proportion being somewhat higher in the case of true tethyan elements (Passendorferiinae), and specially high for cuban elements (Vinalesphinctes). lt seems, therefore, adequate individualising this last genus and related forms under a new subfamilial taxa: Vinalesphinctinae, nov. Its origin as a true Eastern Pacific Realm group, or else, as a «peripheral stem» of Tethyan stock, is stil under discussionItem type: Item , Síntesis y bioestratigrafía de los carnívoros pliocenos de las cuencas centrales españolas(Sociedad Geológica de España, 1987) Alcalá, Luis; Morales, J.; Soria, D.A revision of the Pliocene carnivores from the Spanish Central Basins is presented in this paper. Through the study of data from Six different localities, we can establish the following characteristics: mustelid scarcity, temporal persistence of species and presence of some authochthonous evolutive trends. In conclusion, a similar type of carnivore fauna is present through the Pliocene, in contrast with the ungulate faunal changesItem type: Item , Ridge distribution and fluidized crater occurrence on Mars(Sociedad Geológica de España, 1987) Chicarro, A. F.The planetwide distribution of Martian ridges reveals that compressive stresses have occurred well beyond the Tharsis-dominated hemisphere. Regions of high ridge density show a large number of fluidized craters, whose morphology indicates the Iow viscosity of the target material. Ridge formation has occurred in regions and at times of Iow viscosity, in response to compressive stressesItem type: Item , Relaciones blastesis deformación del granate en la zona de cizalla de Berzosa(Sociedad Geológica de España, 1987) González Casado, J. M.; Casquet Martín, CésarDeformation partitioning is responsible for the various textural and compositional features shown by garnets in the Berzosa Shear Zone. This process is time-and spacedependent across the faultItem type: Item , Presencia de una paragénesis Cu-Ni-Co-U-As-S en la zona cantábrica: la Mina Profunda (Cármenes-León)(Sociedad Geológica de España, 1987) Paniagua, A.; Rodriguez Pevida, L. S.; Garzón, L.; Pérez, J. M.; Quintana, A.The Profunda Mine is an epithermal, carbonate-hosted ore deposit located between late-hercynian faults, showing a remarkable supergenic alteration. This is the first significant evidence of uranium in the Cantabrian ZoneItem type: Item , Presencia de rinoceronte en la fauna de Cueva Millán (Burgos)(Sociedad Geológica de España, 1987) Cerdeño, EsperanzaThe last digging in the Pleistocene site of Cueva Millán (Burgos) has showed the presence of Rhinocerotidae among its fauna. The finding consists of a left maxilar fragment with P-M3, determined by comparative study as Dicerorhinus hemitoechus. lt shows analogies with the Spanish material from Las Majolicas (Granada), Vaciamadrid (Madrid) and Atapuerca (Burgos)Item type: Item , Paleoseismicity in the Spanish Central Range: evidence from the Pseudotachylites(Sociedad Geológica de España, 1987) Doblas, M.The granitoids of the SW Spanish Central Range show different episodes of formation of pseudotachylites, ranging from post-hercynian to alpine times, and which indicate paleoseismic activity in the areaItem type: Item , Paleobiogeographical aspects of the Ordovician mediterranean faunas(Sociedad Geológica de España, 1987) Gutiérrez Marco, Juan Carlos; Rábano, IsabelThe distribution of the faunas and sediments of mediterranean character is related to paleogeographical aspects (epicratonic seas at high latitudes surrounding the Gondwanan continent) as well as to global transgressive-regressive cycles which, together with some oceanic currents, facilitated the interprovincial dispersal of certain characteristic elements throughout several epochs of the Ordovician PeriodItem type: Item , Los depósitos de hierro oolítico del Paleozoico de Asturias y N de León: ambiente de depósito y relación con el vulcanismo(Sociedad Geológica de España, 1987) García Ramos, José Carlos; Suárez de Centi, C.; Paniagua, A.; Valenzuela, M.The depositional setting of the Palaeozoic oolitic iron formations of the Cantabrian Mountains is proposed. They acumulated in a shallow sublittoral environment influenced by the repetitive alternation of siliciclastic supplies, storm processes and fairweather conditions. The genesis of iron compounds is mainly related with subaerial weathering of basic volcanic rocksItem type: Item , Longitudes de fracturas y cavidades en el karst de Larra (Pirineos)(Sociedad Geológica de España, 1987) López Martínez, Jerónimo; Martín Escorza, CarlosA fracture and cave length distribution model has been established by statistical analysis. Structural analysis of 2142 fractures and 1233 caves shows that the best lenght distribution model for the karstic massif of Larra can be formulated as If=5 /c+50, where If is the fracture lenght, and Ic the cave lenght, all parametres being in metresItem type: Item , La Raña al sur de la Somosierra y Sierra de Ayllón: un piedemonte escalonado del Villafranquiense Ihedio(Sociedad Geológica de España, 1987) Pérez González, Alfredo; Gallardo, J.The Raña located NE of Madrid is a piedmont alluvial plain of Middle Villafranquian age. lt is divided into several platforms which are the result of neotectonic processesItem type: Item , La campaña Galinaute del sumergible «Nautile»: tres tipos de fondos marinos en la parte profunda del margen de Galicia(Sociedad Geológica de España, 1987) Boillot, G.; Comas, M. C.; Girardeau, J.; Kornprobst, J.; Loreau, J. P.; Malod, J.; Mougenot, D.; Moullade, M.In 1986 the french submersible Nautile dived to 3.500 m-5.500 m at Galicia Margin in the area drilled by the JOIDES Resolution 0-V (CDP, Leg 703). Three different kinds of seafloor were investigated: a) the Galicia passive margin (basement and sediments); b) a basaltic seafloor (probably a piece of Cretaceous oceanic crust of the Biscay Bay; c) a 100 km long belt of serpentinized peridotites (ultramafic seafloor) extended between the oceanic and the thinned continental crustItem type: Item , La asociación magmática del batolito de los Pedroches: ensayo de caracterización(Sociedad Geológica de España, 1987) García Casco, Antonio; Pascual Martínez, Emilio; Castro Dorado, AntonioA typical granitoid association of the Hercyno-type suite occurs in the los Pedroches batholith, composed mainly of biotite ± amphibole granodiorites, biotîte-cordierite porphyritic monzogranites and cordierite leucogranites, with minor basic rocks. Plotting of major-element chemical data of these types of rocks on multicationic diagrams (Debon & Le Fort, 1982; Batchelor & Bowden, 1985) indicates a clear distinction of at least two different series throughout the batholithItem type: Item , Ignimbritas paleógenas en Mallorca (islas Baleares)(Sociedad Geológica de España, 1987) Alvaro López, M.; Zamora, Olmo; Aguilar Tomás, M. J.An ignimbritic sheet interlayered in Paleogene (Oligo-Miocene?) continental deposits in the Northern Ranges of Majorca is made up of rhyolites and K-rich rhyolites, of presumed calc-alkaline origin. This volcanic activity is interpreted in the framework of an active margin with development of marginal basins during Tertiary times in the Westerm Mediterranean, in accordance with pre-established modelsItem type: Item , Generaciones de cabalgamientos y pliegues recumbentes en los Mantos Alpujárrides entre Ronda y Almería, Cordilleras Béticas(Sociedad Geológica de España, 1987) Balanyá, Juan Carlos; Campos, J.; García Dueñas, V.; Orozco, Miguel; Simancas Cabrera, J. F.Synmetamorphic thrust nappes, related to the Los Reales Crustal Thrust within the Alpujarride Nappes, moved in an ENE or NE direction. A subsequent movement took place in a northerly direction and large fold nappes were formed. Finally N and NW brittle thrusting occurred, consistent with the Gibraltar Crustal Thrust and the N-S convergence of Iberia and AfricaItem type: Item , Episodios sedimentarios en el Alcudiense Superior (Proterozoico) y su tránsito al Cámbrico en la zona centro meridional del Macizo Ibérico(Sociedad Geológica de España, 1987) Vilas, Lorenzo; García Hidalgo, J. F.; San José Lancha, M. A. de; Pieren Pidal, A.; Peláez Pruneda, J. R.; Perejón, A.; Herranz Araújo, P.The evolution of the Upper Alcudian-Lower Cambrian basin is studied in the eastern Lusitanian-Alcudian Zone. Five sedimentary episodes with distinctive characteristics are consideredItem type: Item , Engrosamiento de la corteza y relieve intraplaca en el centro de Iberia(Sociedad Geológica de España, 1987) Vegas, Ramón; Suriñach, EmmaA moderate thickening of the crust beneath the Spanish Central System has been determined by means of a wide angle seismic experiment. The value of this thickening — 5 km in form of 3 km of the Moho topography, 2 km of surface relief — is coherent with the surface model of intracontinental distributed deformation already described. In addition, the present model is in agreement with the intraplate uplift, the reverse faults that bound the relief and to some extent with the intrap/ate shortening of IberiaItem type: Item , El plutón de Santa Eufemia (batolito de los Pedroches, Córdoba, España): un granitoide epizonal de tipo S(Sociedad Geológica de España, 1987) García Casco, Antonio; Pascual Martínez, EmilioA petrogenetical approach is presented for a monzo-granite pluton (Santa Eufemia) in Los Pedroches Batholith (Central Iberian Zone, Iberian Massif, Spain). From petrological and geochemical data, an S-type character is deduced, and P-T-X generation constraints, including magma source composition, are presented. Other previously suggested hypotheses, such as magma mixing, are to be rejected for the studied rocksItem type: Item , El límite Dogger-Malm en la Cordillera Ibérica: anomalías geoquímicas y fenómenos asociados(Sociedad Geológica de España, 1987) Meléndez Hevia, Guillermo; Sequeijos, L.; Brochwicz Lewinski, W.; Gasiewicz, A.; Suffzynsky; Szatkowski, K.; Zbik, M.; Tarkowski, R.The hypothesis put forward by Raup and Sepkoski, linking major mass extintions with cyclic cosmic catastrophes, focussed attention on several geological boundaries. This was also the case of the Middle/Upper Jurassic boundary in Poland and Spain (Iberian Chain). Some «rare events» have been detected: possible submarine corrosion processes, Iranomaly and high enrichment in heavy metals (Fe, Mn, Ni, Co, Ra and Pt), cosmic dust, etc.Item type: Item , Discordancia intra-Alcudiense en el anticlinal de Agudo (Ciudad Real-Badajoz)(Sociedad Geológica de España, 1987) Pieren Pidal, A.; Pineda Velasco, A.; Herranz Araújo, P.The Proterozoic unconfomity, also known more to the East, is described in the Agudo Anticline at the base of the Upper Alcudian (Upper Vendian) and extended to the whole anticlinory. This allows the extension of the Intra-Alcudian unconformity to the W