Geogaceta -- Nº 13, (1992)
Permanent URI for this collectionhttps://hdl.handle.net/10272/13961
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Item type: Item , Un ejemplo de tectónica salina: el sector NE del Surco de Valencia(Sociedad Geológica de España, 1992) Säbat, F.; Sans, M.The messinian salt develops salt rollers, pillows and diapirs in the linking zone between the Valencia Trough and the Provenga! Basin. The correlation of the different structures based on the sedimentary wedges linked to the salt rollers formation, the onlap surfaces and truncations, as well as a sequential restitution of the salt structures allows us to propose different origins for the salt structures of different areas of the basinItem type: Item , Tectónica sinsedimentaria en un talud carbonatado con resedimentación gravitatoria en masa (Ibarra, Albiense Inferior, Bizkaía)(Sociedad Geológica de España, 1992) Gómez Pérez, I.; Fernández Mendiola, Pedro Ángel; García Mondéjar, JoaquínThe analysis of fades and thickness distribution in carbonate slope systems of the Albian of Ibarra (Bizkaia) indicates active synsedimentary faulting. E-W extensional faults separate blocks that record tilting and depocenter shifts through time. This local extension occurs associated to major NW-SE strike-slip sinistral movements linke d to the opening of the Bay o f BiscayItem type: Item , Secuencias deposicionales en las facies terrigenas del Cretácico en la región del Alto Tajo (Cordillera Ibérica). Provincias de Guadalajara y Cuenca(Sociedad Geológica de España, 1992) Ruiz Cebrián, G.Four depositionsI sequences have been recognized in the Cretaceous terrigenous facies in the studied area of the Iberian Ranges. The 1st and 2nd sequences are caracteristics of continental environments, and the 3th and 4th sequences are caracteristics of coastal and/or tidal environments. The proposed age is Hauterivian- Barremian for the 1st, Aptian for the 2nd, Lower Cenomanian for the 3th and middle Cenomanian for the 4th sequenceItem type: Item , Secuencias deposicionales del Cretácico en el flanco sur del Sistema Central(Sociedad Geológica de España, 1992) Gil, J.; García, A.; Segura, M.Eight depositional sequences have been recognized in the Cretaceous of the southern border of the Central System. The thickness of sedimentary succession, the marine character of the sediments and the number of depositional sequences decrease westwards. It is possible to recognize a stratigraphic structure in onlap with diacronic distribution of the dolostones, marls and terrigenous facies. This stratigraphic succession is related to the Cretaceous of the Nothern Iberian Ranges and from a paleogeographical point of view, i t correlates to the Atlantic Margin of the Iberian Plate. Its age is Cenomanian to Campanian.Item type: Item , Secuencia diagenètica temprana de la plataforma carbonatada con paleocarst de Arenillas (Albiense, Oriñón, Cantabria)(Sociedad Geológica de España, 1992) Rosales, Idoia; García Mondéjar, JoaquínThe five shallow water carbonate depositlonal sequences oftheAlbian Arenillas platform in Oriñón, N Spain, are bounded by palaeokarst surfaces. Detailed petrographic and cathodoluminescence studies have revealed that the early diagenesis was similar in each cycle. This early diagenetic sequence shows 5 consecutive stages: 1) Stagnant marine phreatic zone, 2) Active marine phreatic zone, 3) Mixing marine and meteoric phreatic zone, 4) Meteoric phreatic zone and 5) Vadose and marine-vadose zoneItem type: Item , Reconsideración del límite Oxfordiense-Kimmeridgiense en el perfil de Puerto Lorente (Prebético Externo)(Sociedad Geológica de España, 1992) Olóriz, F.; Rodríguez Tovar, F. J.In the Puerto Lorente section at the Sierra de Cazorla (External Prebetic), the uppermost Oxfordian is made up of limestones with recognizable traces of increasing condensation. O verlayin gare marls, marly-limestones and limestones of the Lower Kimmeridgian. The surface boundary between the Oxfordian and the Kimmeridgian has been traditionally referred to the cephalopod rich “hardground" which precedes deposition of the lowerm ost Kimmeridgian marls. Nevertheless, careful studies on this surface allowed us to identify rare specimens of Sutneria platynota (REINECKE) and therefore to improve the previous biostratigraphic interpretations. The obtained data will be valuable for the updated interpretation of the eco-sedimentary evolution in epicontinental areas of the Southlberian paleomargin around the Oxfordian-Kimmeridgian boundaryItem type: Item , Propiedades petroestructurales de rocas madres de petróleo. Pizarras bituminosas del Cretácico superior de la cuenca vascocantábrica(Sociedad Geológica de España, 1992) Marfil Pérez, Rafaela; Dorronsoro Urrutia, C.; Permanyer, Albert; Aguiló, R.Black shales from Carai (Vizcaya) have been studied from the following points of view: mineralogy, geochemistry (pyrolysis rock-eval), porosimetry measurements and clay fabric. Data obtained suggest that: a) The presen ce of organic matter exerts a secondary influence in con trolling porosity and clay fabric, b) A significant percentage of carbonate minerals inhibit clay particle orientation, c) There is little or no connection between porosity and/or fabric and clay mineral composition, except perphaps in sediments with appreciable mixed-layers l-S content, d) There seems to be no relationship between porosity and/or fabric and total clay content, e) Compaction processes are not the main control on the structural properties of these rocksItem type: Item , Primeros resultados obtenidos en experiencias de laboratorio destinadas a caracterizar el comportamiento de contaminantes inorgánicos en materiales arenosos(Sociedad Geológica de España, 1992) Temiño Vela, Javier; Bustamante, I. deWe describe the lisimetric column construction and we test it with two experiments using inorganic polluants in a sandy sample. We notice the tampon effect in the soil with the pH variations, and we observe the different stages of retention for each tested ionItem type: Item , Pistas fósiles en la «Serie de Carrascalejo». Implicaciones cronoestratigráficas(Sociedad Geológica de España, 1992) García Hidalgo, J. F.Trace fossils (Cruziana and Rusophycus) are described for the first time in the Carrascalejo beds. The stratigraphy of this unit is also modified; the conglomeratic basal beds are included in the underlying Precambrian series. An Upper Cambrian-Tremadocian age for the Carrascalejo beds is based both on trace fossils and on the regional stratigraphyItem type: Item , Nuevos datos sobre la estratigrafía de las escamas de la Hafa el Banat y de Fahs Dohor (Hauz interno, Rif Septentrional, Marruecos)(Sociedad Geológica de España, 1992) Maaté, Ali; Martín Algarra, AgustínThe stratigraphic succesions of the Hafa el Banat and of the Fahs Dohor slices (Internal Hauz, Northern Rif) are described. Both slices show stratigraphic features and a tectonic position similar to that of the Uestia II Slice of southern sectors of the Hauz belt and, as well as this latter, they were a part of a subsiding continental margin during the MesozoicItem type: Item , Metapelitas de alta presión de la Unidad de Santiago (Complejo de Ordenes, NO del Macizo Ibérico)(Sociedad Geológica de España, 1992) Rubio Pascual, F. J.; Arenas, R.; Díaz García, F.A high - pressure - low - to intermediate temperature eo - Hercynian metamorphic event characterizes the tectonothermal evolution of the Santiago Unit, in the western margin of the Ordenes Complex. P-T conditions fo r the mineral assemblages of the high - pressure event (which is essentially preserved as a very thin Si=S1 included in albite porphyroblasts in semipelitic schists) have been estimated at 493 ± 9 °C and 14.7 ± 0.7 kbar (minimum pressure). The development of the high - pressure metamorphism and the lacking of significative reequilibrium of their characteristic mineralogy, suggests that the unit (probably a fragment o f the continental margin of Condwana) has been uplifted inm ediately after undergoing subduction in the beginning of the Hercynian OrogenyItem type: Item , Litificación de carbonatos lacustres Miocenos. Cuenca de Madrid: ¿Implicaciones en el estudio de la diagénesis de carbonatos marinos calcíticos?(Sociedad Geológica de España, 1992) Sanz Montero, María Esther; Wright, V. P.; Calvo, J. Pedro; Alonso Zarza, Ana MaríaAs a possible model for lacustrine carbonate diagenesls, and as a guide for understanding calcitedominated marine limestones, a range of indurated Miocene limestones from the Madrid Basin were studied. Despite very shallow burial and a calcitic precursor, the micrites and bioclasts underwent two phases of recrystallization. Initially the muds and bioclasts were recrystallized to a microporous uniform luminiscent micrite with complete loss of any primary fabric, possibly in a shallow suboxic phreatic zone. Subsequent exposure and karstificatión (probably in the early Pliocene) resulted in microspar/pseudospar formation causing induration. Low Mg calcite muds appear particularly susceptible to recrystallizationItem type: Item , Líneas evolutivas de los Alveolínidos cretácicos de la Cordillera Ibérica (España)(Sociedad Geológica de España, 1992) Calonge García, María A.In this paper the presence of three different evolutive lineages of cretaceous Alveolinids is verified, using material coming from the Iberian Ranges. One of then begins with Ovalveolin a maccagnoae, the other with Praealveolina iberica, and the last one deals with Simplalveolina genreItem type: Item , Li-Mineralization at Tres Arroyos (Alburquerque, Badajoz) as a result of the mineralogical and geochemical evolution of the Alburquerque batholith(Sociedad Geológica de España, 1992) Gallego, M.; Gumiel Garrido, P.La mineralización de Tres Arroyos está formada por un haz de pegmatitas litin fieras situado en el límite SW del batolito de Alburquerque. Los diques pegmatíticos aparecen en transición petrológica y geoquímica con el batolito, constituido por granitos de dos micas y diversas facies leucogranfticas marginales. Geoquímicamente, los grupos litológicos establecidos corresponden a granitos calcoalcalinos, peralumínicos, fértiles, con elevados contenidos en P y F. La evolución geoquímica observada se caracteriza por un fraccionamiento extremo, con concentración de elementos incompatibles (Li, Rb, Cs, Ga, Sn, Nb, Ta) en las fracciones magmáticas residuales y una evolución compleja en cuanto a los contenidos en Tierras RarasItem type: Item , Las pistas fósiles del Alcudiense superior en el anticlinal de Ibor. Consideraciones cronoestratigráficas(Sociedad Geológica de España, 1992) García Hidalgo, J. F.New discovery of trace fossils in the Upper Alcudian of the Ibor anticline indicate that its supposed Precambrian age should be maintained but tentatively, due to the presence of scarce Lower Cambrian trace fossils although their distinction is problematic. Other fossil data, micro and macroflora, are also revisedItem type: Item , La falla de San Saturio (Soria)(Sociedad Geológica de España, 1992) Aracil Ávila, E.; López Mendieta, F. J.; Rubio, V.; Sanz, E.; Savirón, L.In this paper we intend to offer a geological interpretation of the northern border of the Almazân basin based on a geophysical prospection . The contact of this basin with the Iberic Range has been very conditioned by the San Saturio faultItem type: Item , Incidencia ambiental de un vertedero sellado de residuos sólidos localizado en Móstoles (Madrid) sobre la composición natural de las aguas subterráneas(Sociedad Geológica de España, 1992) Adarve Alcázar, M. J.; Rebollo Ferreiro, Luis F.In this paper, some considerations about the negative effects due to leachates of Mdstoles sealled landfill on groundwater quality are presented. The results show an important increase in the values of Conductivity, COD, NHA* and, in general, in most of the 18 chemical elements analyzedItem type: Item , Geocronología por el método Rb-Sr de las episienitas de la Sierra del Guadarrama, S.C.E., España(Sociedad Geológica de España, 1992) Caballero, J. M.; Casquet Martín, César; Galindo, Carmen; González Casado, J. M.; Tornos, Fernando; Pankhurst, R. J.Rb-Sr dating by internal isochrones of the episyenitea (hydrothermally dequartzified and alkalimetasomaticed granites) from the Sierra de Guadarrama gives an age of 274+-6 M.y., i.e.. Early Permian. The epysienites were formed shortly after E-W dyke swarms (granitoid porphyries and microdiorites); which probably behaved as "heat engines" for the hydrotermal systemsItem type: Item , Existencia de una plataforma carbonatada del Albiense Superior entre materiales terrígenos de mar somero (Karrantza-Trucíos, Bizkaia)(Sociedad Geológica de España, 1992) López Horgue, Mikel A.; Aranburu Artano, Arantza; Fernández Mendiola, Pedro Ángel; García Mondéjar, JoaquínFacies analysis and distribution in the Karrantza and Trucfos Valleys have allowed a detailed correlation of Upper Albian series. A new carbonate platform belonging to the Urgonian Complex is described and correlated with siliciclastic platform sequences of Upper Albian (Hysteroceratian) age. The stationary platform margin shows no signs of steep slopes and was surrounded by a shallow basin dominated by siliciclastics derived from a broad deltaic systemItem type: Item , Evolución tectonotermal de la Unidad de Santiago (Complejo de Ordenes): un ejemplo de subducción eo-hercín¡ca y descompresión sin-colisional(Sociedad Geológica de España, 1992) Rubio Pascual, F. J.; Arenas, R.; Díaz García, F.The syn-D2 uplift of the Santiago Unit, inmediately after of the high-pressure eo-Hercynian metamorphic event, cause a markedly decompressive-slightly prograde P,T,t path. This path very likely suggests that the majority of the rising history of the unit took place in a context of ductile extension, related to the continued underplating of the continental margin of Condwana and compensating extension above. The actual disposition of the syn-D2 metamorphic zones is inverse, w ith the staurolite zone (which represents the thermal peak) occupying the top o f the unit