Geogaceta -- Nº 16, (1994)

Permanent URI for this collectionhttps://hdl.handle.net/10272/13752

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Geometría, piezometría y parámetros hidráulicos de los acuíferos de la cuenca baja del río Loukkos (Marruecos)
(Sociedad Geológica de España, 1994) Bouhmadi, B.; Benavente Herrera, José; Cruz Sanjulián, J. J.
The alluvial materials of the Loukkos river (Morocco) downstream from Ksar-El-Kebir present transmissivity values in the 10-3 - 10-2 m2/s range and storativity values of 10-4-10-3 . The adjacent Oulad-Ogbane conglomerate formation drains towards the alluvium and is characterized by Iower T and higher S values. The morphology of the potentiometric surface (April, 1992) shows a general downstream hydraulic gradient ofnear 0.2 0/00 and a well-marked conoid —extending over TO km2 and with its apex slightly below the sea level— induced by the Ksar-El-Kebir supply pumping. The geometry of the substratum indicates a depression —elongated in the NW-SE direction— in the OuIad-Ogbane zone where depths of50 m below the sea leve/ are encountered
Un sistema de paleoalto carbonatado-surco siliciclástico (Gorbea-Artzentales, Albiense medio, Bizkaia)
(Sociedad Geológica de España, 1994) Gómez Pérez, I.; Aranburu Artano, Arantza; Fernández Mendiola, Pedro Ángel; García Mondéjar, Joaquín
During the middle Albian, fault block synsedimentary activity induced the formation of a paleohigh (Corbea) and an adjacent sedimentary trough, While (he high was exposed in the subaerial meteoric environment realm, the trough was filled by athick wedge up to 2 km of deeper water siliciclastics
Testificación geofísica en granitos
(Sociedad Geológica de España, 1994) Aracil Ávila, E.
In this paper we analyze fractures with logs performed in deep wells in granitic rocks. We explain the methodology followed for determining these fractures and their characteristics: clay content, fluid content, closed or open fractures, etc
Sr-Nd isotopic heterogeneities in high-grade metamorphic conditions: an example from the anatectic complex of Toledo (Spain)
(Sociedad Geológica de España, 1994) Barbero, Luis; Rogers, Graeme; Villaseca, Carlos
Preliminary data on the study of Sr-Nd isotopes in metapelitic, restite-rich granitoids and anatectic leucogranites from the Anatectic Complex of Toledo (Centro-lberian Hercynian zone), reveal the absence of isotopic homogenization as it would be expected in a high grade metamorphic area in which important volumes of anatectic leucogranites are generated. Several factors as the short-lived metamorphic climax, the highly anhydrous conditions, and the source heterogeneity seem to be crucial for isotopic homogenization to be not achieved
Serie Basáltica Antigua Inferior en el sector de Hermigua. Isla de la Gomera
(Sociedad Geológica de España, 1994) Cubas, C. R.; Hernán, Francisco; Ancochea, Eumenio; Brändle, José Luis; Huertas, María José
Lower Old Basaltic Series had only been described W of the Basal Complex in Alojera -Tazo area but it is also well exposed in other zones on Comera as in Hermigua area E of the Basal Complex. Here, the basaltic lava flows alternate with poligenetic agglomerates. The lowermost lavas show some submarine features. Their chemical affinity is mildly alkaline and the ir age is about 9 -1 0 A4. y.
Rellenos de valles encajados en el Maastrichtiense superior y Paleógeno inferior de Alava (Plataforma Noribérica, Cuenca Vasca)
(Sociedad Geológica de España, 1994) Baceta, Juan Ignacio; Pujalte, Victoriano; Payros, Aitor
Three examples of sillciclastic valley fills are recognized within the upper Maastrlchtian-lower Paleogene carbonate platform deposits of Alava. A genetic model, in the context of sequence stratigraphy, makes it evident the existence ofdiferent types ofmeaninful stratigraphic boundaries
Nuevos datos sobre la petrología y procedencia de la Formación Miers Bluff, Isla Livingston, Islas Shetland del Sur
(Sociedad Geológica de España, 1994) Marfil Pérez, Rafaela; López Martínez, Jerónimo; Arche, A.
The turbidites of the Miers Bluff Formation have been pelrologically analised and some compositional parameters have been calculated. The use of several ternary diagrams allow for some provenance speculations such as a source area of low metamorphic composition with progessive influence of dykes and volcanic rocks. Albitization of feldspars in part of the section poses a difficulty in a sure source area reconstruction
Nuevos datos sobre la litoestratigrafia del Eoceno-Oligoceno inferior de la zona suroriental de la Cuenca del Ebro (Sector de Pontils-Montblanc, provincias de Tarragona y Barcelona)
(Sociedad Geológica de España, 1994) Colldeforns, B.; Anadón, P.; Cabrera, L.
This paper deals with new data on the lithostratigraphy of the Upper Paleocene-Lower Oligocene successions in the Pontils-Montblanc area (western part of the southeastern margin of the Eastern Ebro Basin, NE Spain). The new contributions point to the fact that the Bartonian-Priabonian marine and transitional facies of the Sta. Maria Group extend to the southwest as far as Barberà de la Conca. This fact together with the mapping of the recorded major progressive and angular syntectonic unconformities and the geometric relationships between the Upper Eocene-Lowermost Oligocene alluvial and lacustrine units have provided enough elements to modify the lithostratigraphic framework. This new framework will constitute the base for further stratigraphic and tectonosedimentary analysis
Nuevos datos estratigráficos de la Unidad Central, Hauz Intermedio (Dorsal Rifeña). Consecuencias paleogeográficas
(Sociedad Geológica de España, 1994) Hlila, Rachid; Sanz de Galdeano, Carlos; Serrano Lozano, Francisco
The presence both of radiolarites, attributed to the Dogger-Malm, and grey marls from the early Late Eocene in the Intermediate U n it o f the Haouz M ountains (Rifian Dorsal) indicates that the sea occupied the area at this times. These data modify previous palaeogeographical reconstructions
Modelo hidroquímico de sedimentación de glauberita-halita: sondeo PURASAL, Formación Yesos de Zaragoza (Mioceno Inferior, Cuenca del Ebro)
(Sociedad Geológica de España, 1994) García Veigas, Javier; Ortí, Federico; Fernández Nieto, C.
The geochemical study of halite samples belonging to PURASAL borehole (Zaragoza Gypsum Fm., non-marine Lower Miocene, Ebro Basin, Spain) shows low contents for Br, Mg and l<. The study of fluid inclusions (Cryo-SEM -EDS method) of these samples reveals very low contents of Kand S04 in the brines, and contents of Ca and Mg that are below the detection limit. The amount of S04 is significant only in a few halite samples associated with glauberite beds. These data agree with the mineral paragenesis (gypsum/anhydrite, glauberite, thenardite (?) and halite) where no Mg and/or l< minerals are observed in contrast to what occurs in other sodium sulphate deposits of Tertiary age in Spain which are characterized by the presence of polyhalite and magnesite
Modelo alternativo para el desarrollo de calcretas: Un ejemplo del Plio-Cuaternario de la cuenca de Madrid
(Sociedad Geológica de España, 1994) Sanz Montero, María Esther; Wright, V. P.
Plio-Quaternary calcrete profiles from the Mesa de Ocaha, South of Madrid Basin, have developed by vertical accretionary processes and differ from the classical model of calcrete development based on studies in the United States and Australia. The profiles have laminar or chalky horizons, with the former reaching thicknesses of 2 m. Unlike previously described types, these laminar forms did not develop on hardpan horizons but appear to have formed as thin indurated layers within the soil. Internally the laminar horizons exhibit complex textures wich may reflect polyphase histories of multiple climatic changes and landscape instability. This style of calcrete formation, while differing from that seen in the classical model, may be more widespread than has been appreciated and is similar to that seen in the tepetate soils of Mexico
Las «megaturbiditas» y otros depósitos de resedimentación carbonatada a gran escala del Eoceno surpirenaico: nuevos datos del área Urrobi-Ultzama (Navarra)
(Sociedad Geológica de España, 1994) Payros, Aitor; Orue Etxebarria, Xabier; Baceta, Juan Ignacio; Pujalte, Victoriano
The number of carbonate megaturbidites and related deposits in the Urrobi-Ultzama area, west part of the South-pyrenean Eocene basin, is greater than was hitherto realized. Planktonic foraminifera analyses also demonstrate that their ages are somewhat older than were previously believed. Paleocurrent measurements and other evidences finally reinforce a southern derivation for these largescale resedimented deposits
La falla de Ubierna (margen SO de la cuenca Cantábrica)
(Sociedad Geológica de España, 1994) Hernaiz Huerta, Pedro P.
The Ubierna fault is a major structure in the southern margin of the Cantabrian Basin. It controlled the subsidence during the intra-Mesozoic extensional event allow ing the deposit of progressively to the north thicker syn-rift Upper Jurassic-Lower Cretaceous sediments in the Polients trough. Later it was inverted as a reverse fault during the main Tertiary compression changing to a strike-slip behaviour in the latest compressive movements.
La evolución temporal de los minerales de la arcilla en el Pérmico superior y Triásico de Cuenca y Teruel (Cordillera Ibérica SE)
(Sociedad Geológica de España, 1994) Alonso Azcárate, Jacinto; Arche, A.; Barrenechea, J. M.; López Gómez, José; Luque, F. J.; Rodas, M.
Clay mineralogy of the continetal and shallow marine sediments of Permian and Triassic age of the SE Iberian Ranges is a neglected subject. The present study shows the temporal variations of clay mineral assemblages and point out to two main primary controls: nature of the source area and sedimentary environments. Later diagenetic processes have not altered substantially the original mineralogy
La Cuenca Central de Bransfield (NW de la Peninsula Antàrtica): primeros resultados de la campaña GEBRA'93
(Sociedad Geológica de España, 1994) Canals, M.; Acosta, J.; Baraza, J.; Bart, P.; Calafat, A. M.; Casamor, J. L.; Batist, M. de; Ercilla, Gemma; Farrán, M.; Francés, Guillermo; Gràcia, E.; Ramos Guerrero, Emilio; Sanz, J. L.; Sorribas, J.; Tassone, A.
The GEBRA '93 (Geological Evolution of the Bransfield Basin) survey was carried out in December 1993 in the Bransfield Strait (NW Antarctic Peninsula) and adjacent areas, onboard BIO Hespérides. The geophysical data acquired allow to characterize the morphostructure, sediment cover and magnetic anomalies of the SW-NE trending Central Bransfield Basin. Some transverse shifts and tresholds, together with alongbasin volcanic alignments, complicate the morphology and seismic structure of what otherwise would have been a long, continuous axial trough opened on a crust under extension. A major submarine valley, named Gebra Valley has also been identified
Introducción al estudio de indicios manganesíferos, situados en las inmediaciones de Requena, País Valenciano
(Sociedad Geológica de España, 1994) Mata Perelló, Josep Maria
Inside the sector of «Muntanya de Valencia» (Iberian Range), there are a number of Mn mineralizations. Some of these deposits have been explored for mining. In every case there are paleokarst mineralizations which have developed into Cretaceous limestone. Mn oxides are always the commonest minerals. The most Important examples are found close to Campo Arcís (Requena)
Hallazgo de Parotosuchus sp. (Amphibia, Temnospondyli) en las facies Buntsandstein del Pia de la Calma (Cordilleras Costeras Catalanas): resultados preliminares
(Sociedad Geológica de España, 1994) Gaete, R.; Galobart, A.; Palomar, J.; Marzo, M.
The tetrapod fauna of La Mora site (Montseny massif) is located in the Buntsandstein facies at the lower part of the « Areniscas y lutitas del Figaró» unit. This fauna is found within a sandy, fluvial channel-fill and is dominated by remains of tem nospondyl amphibians. General features of the skull and the mandible indicate that these remains pertain to the genus Parotosuchus. This is a prim itive genus in the family Capitosauridae, which is typical of the continental triassic faunas around the world
Geometría de los volcanes de lodo y de los pliegues de la Dorsal Mediterránea al Sur de Creta (Mediterráneo Oriental)
(Sociedad Geológica de España, 1994) Galindo Zaldívar, Jesús; Nieto, Luis M.
Side scan sonar images and high resolution profiles obtained with the R/V Gelendzhik in the 1993 cruise of the TREDMAR program, give new information on the geometry of the mud volcanoes, folds and fractures located in the central part of the Mediterranean Ridge. Mud volcano emplacement modify the regional stress field related to the subduction of the African plate below the Eurasian plate, and originate a fold system with concentric hinge lin es around the area with highest quantity of mud volcanoes. Mud volcanoes can be formed from anticlinal folds whose nucleus have been intruded by breccias with a high content of mud matrix. Flows of mud breccias from anticlinal emission areas produce mud volcanoes whose elongation is parallel to fold axis trends
Geometría y sistemas de flujo en el acuífero de Turón-Peñarodada (Almería-Granada): implicaciones estruccturales
(Sociedad Geológica de España, 1994) García López, Santiago; Benavente Herrera, José; Cruz Sanjulián, J. J.; Carrasco Cantos, Francisco
The results of a pumping/recovery test and those of a physico-chemical sampling of groundwater from the Turon-Peñarrodada triassic carbonate aquifer (Almeria and Granada provinces, SE Spain), together with the analysis of the relationship between the TSD evolution in the main discharge point-Fuentes de Marbella springs- and the piezometric trend, are commented
Fracturación y deformaciones sinsedimentarias en el Eratosthenes Seamount (Mediterráneo Oriental)
(Sociedad Geológica de España, 1994) Nieto, Luis M.; Galindo Zaldívar, Jesús
The Eratosthenes Seamount is located in the Eastern Mediterranean, between the Levantine Platform to the South and the Cyprus Margin to the North. During the 3rd leg made by the RA/Gelendzhik (TREDMAR-1993 UNESCO Programme) they were made differents seismic and sidescan sonar lines and nine gravity cores. We differentiate several areas taking into account the fault systems. A compression al zone located North to the Eratosthenes, related with the subduction of the African Plate beneath Eurasian Plate. An extensiona! area is situated in the top of the seamount, the northern and southern slopes. Another compressional zone is located south of the Eratosthenes, with reverse faults that separate the Levantine Platform from the seamount. In the Southwest area we have a complex system of faults that are grouped into two sets with N-S and NW-SE strikes. In relation with the fault systems there are three groups of synsedimentary deformational structures: slided sediments with preservation of internal features, slid ed sediments without preservation of internal structures, and structures related with the development of asymmetric basins

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