Geogaceta -- Nº 35, (2003)

Permanent URI for this collectionhttps://hdl.handle.net/10272/8906

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Yacimiento de arcilla caolinífera de relleno Kárstico en Chavaler (Cordillera Ibérica, Soria)
(Sociedad Geológica de España, 2003) Sanz Pérez, Eugenio
The Chavaler karstic deposit is a clay accumulation in a dolina of 90 m in diameter. Clay minerals are represented mainly by kaolinite (80% kaolinite, 20% quartz) and locally also kaolinite-gibbsite facies, and natroaluite. The feldespatic detrital material of the Weald Facies was deposited on a pre-existing prefinimiocene-Pleistocene karst. The karst depression has protected kaolinic deposits from further erosion. The favourable drainage contributed to the kaolinization and initial bauxitization
Tres nuevas localidades con fauna de micromamíferos fósiles de edad Aragoniense inferior-medio en el sector sureste de la cuenca de Quesa-Bicorp (prov. de Valencia, España)
(Sociedad Geológica de España, 2003) Ruiz Sánchez, Francisco Javier; Santisteban, Carlos de
In this paper are described three new mammal localities of Lower -Middle Aragonian age in the Quesa-Bicorp basin (Prov. of Valencia, Spain). The new data confirm the age atribution for the lower continental deposits
Respuesta espectral de unidades morfosedimentarias cuaternarias de la Cuenca de Huércal-Overa según su edad relativa (Almería, Sureste de España)
(Sociedad Geológica de España, 2003) García Meléndez, Eduardo; Ferrer Julia, Montserrat; Suárez Barrios, M.; Riaza, A.; Goy, José L.; Zazo, C.
The morphosedimentary Quaternary units present in the Huércal-Overa Basin (Southeast Spain) are studied in terms of their spectral response through laboratory reflectance spectroscopy covering the 400 to 2500 nm wavelength interval. This technique applied to a set of samples composed of mineral mixtures, in order to determine is the relationships between spectral curves and relative chronology. The obtained results show qualitatively the relationship between the relative chronology of the units and. their spectral response, showing its importance as an additional criterion for the assignment of relative ages and for the proper Interpretation of remote sensing images
Rasgos hidrogeoquímicos de las aguas termales en los acuíferos carbonatados del Bajo Andarax (Almería)
(Sociedad Geológica de España, 2003) Sánchez Martos, Francisco; Pulido Bosch, Antonio; Vallejos, Ángela; Molina, Luis; Gisbert, Josep
The carbonate aquifers of the Lower Andarax is a significant geothermal anomaly, as evidenced by the high temperature of the spring waters (22 - 40 °C). The most saline waters (2000 - 3000 mg.L1) correspond to the Deep Aquifer, which presents a sodium chloride sulphate facies, while the least saline (500 mg.L'1), with a magnesium calcite bicarbonate type, are found in some sectors of the Carbonate Aquifer. The sectors of the Carbonate Aquifer having less saline waters and which are directly associated with more rapid flows can thus be identified. In the Deep Aquifer, the situation is more complex, as the intense thermal anomaly of the are a acts in conjunction with the influence of evaporitic materials and a long residence time of the groundwater, factors which tend to produce the high concentrations of boron and lithium
Primera evidencia de restos de dinosaurio en Murcia (Cretácico Inferior, Albiense)
(Sociedad Geológica de España, 2003) Canudo, José Ignacio; Ruiz Omeñaca, José Ignacio; Ramo, A. del; Guillén Mondéjar, F.
A new dinosaur fossil remain from the Albian (Early Cretaceous) of Murcia (Spain) is described. It is a fragmentary proximal end of a left metacarpal I from an indeterminate sauropod. A preliminary review indicates a morphology close to Brachiosauridae, but this remain is assigned to Sauropoda indet. due to its fragmentary preservation. This fossil represents the first dinosaur remain from the Utrillas Formation in Spain and opens the possibilities for future fieldwork in this formation
Preliminary thermobarometric data from the Ouguela and Contenda-Barragem do Caia Units: Coimbra-Cordoba shear zone (Northeast Alentejo, Portugal)
(Sociedad Geológica de España, 2003) Francisco Pereira, M.; Apraiz, A.
The Coimbra-Cordoba shear zone comprises different tectonic units with a complex metamorphic evolution. In the Northeast Alentejo (Portugal) some of these units contain mineral parageneses of high-temperature/ intermediate-pressure metamorphism, which were subsequently retrogressed, to low-temperature/low-pressure conditions. Detailed microstructural studies show that the relationships between metamorphic assemblages and deformation stages in these rocks relate to strong shearing. In this preliminary study conventional geothermobarometrical techniques performed on rocks with appropriate mineral assemblages allows us to determine the P-T conditions near the metamorphic peak of two major rock units: (1) garnet-bearing leucocratic gneisses from the Ouguela Unit (600-700°C and 7-9 kbar), and (2) garnet-rich amphibolites (~550-600°C and 8-10 kbar) and garnet-rich amphibolitic boudins (650-700°C and 8.5-9.5 kbar) associated with calc-silicate rocks from the Contenda-Barragem do Caia Unit. These P-T determinations suggest that the rocks from Northeast Alentejo were buried to lower crustal depths of —25-35 km consistent with the high-grade metamorphism (upper amphibolite facies) deduced from the relict mineral assemblages. Later, during the uplift and exhumation the rocks experienced strong retrogression in the greenschist-facies
Potencial ornamental del plutón de Sierra Bermeja (Badajoz): evaluación de su canterabilidad
(Sociedad Geológica de España, 2003) Sarrionandia Eguidazu, Fernando; Carracedo Sánchez, Manuel; Eguiluz, Luis; Apalategui, Octavio
The Sierra Bermeja pluton is mainly composed of three peraluminous granitic facies: Cornalvo, Moro and Raposeras. The three facies show four main joint systems, two of them developed at regional scale oriented N5/900 and N120/90°, and the other two, related to the cooling process of the pluton, oriented N55/900 and NT45/90. The Moro granite shows the greater potential as dimension stone, with good quarriability and interesting aesthetic characteristics. The Raposeras granite has aesthetic interest but the closely spaced jointing may imply quarriability problems. The aesthetic characteristics of the Cornalvo facies are not fashionable in the ornamental industry and also this facies has specific difficulties to obtain homogeneous blocks
Pliegues limitados por fallas en el subbético medio (sector de torre cardela, Granada)
(Sociedad Geológica de España, 2003) Sanz de Galdeano, Carlos
In the area of Torre Cardela, situated to the NE of Granada, there are NE-SW to NNE-SSW folds comprised among ENE-WSW dextral strike-slip fauts. The formation of all these structures are interpreted as singenetic, within a compressional elipsoid which o1 varies from WNW-ESE to NW-SE direction. These structures form part of the zone of deformations produced by the Cadiz-Alicante strike-slip faults
Paleontología del sistema de yacimientos de mamíferos miocenos del Cerro de los Batallones, Cuenca de Madrid
(Sociedad Geológica de España, 2003) Morales, J.; Alcalá, Luis; Antón, M.; Azanza, Beatriz; Calvo, J. Pedro; Carrasco García, Pedro; Fraile, S.; García Paredes, L.; Gómez, E.; Hernández Fernández, M.; Merino, L.; Van der Meulen, A.; Martín Escorza, Carlos; Montoya, P.; Nieto, M.; Peigné, S.; Pérez, B.; Peláez Campomanes, P.; Pozo Rodríguez, Manuel; Quiralte, V.; Salesa, M. J.; Sánchez, I. M.; Sánchez Marco, Antonio; Silva, P. G.; Soria, M. D.; Turner, A.; Álvarez Sierra, María Ángeles
Six Upper Vallesian (Upper Miocene) fossil vertebrate sites have been found in the Cerro de los Batallones (Torrejón de Velasco, Madrid). These localities contain an exceptionally rich, varied and well-preserved vertebrate fauna. Carnivore species are strikingly well represented at Batallones 1 and 3, and large herbivore species, such as mastodons, rhinoceros and giraffes, are common in Batallones 2, 4 and 5. The mammalian association, together with the morphological features shown by the sedimentary fills of the mammal sites, enables an overall interpretation of these deposits as vertebrate traps. The study of these localities should offer a significant contribution to our understanding of the formation pattern of trap-like paleontological sites which so far have been typically reported in karstic-type systems. These new sites also will contribute to a better knowledge of some of the most scarce mammal groups in the Miocene fossil record
Ostrácodos Tortonienses del Sector Central de la Cuenca del Guadalquivir (Sur de España)
(Sociedad Geológica de España, 2003) Ruiz Muñoz, Francisco; Abad de los Santos, Manuel; Pendón Martín, José Gabriel; González-Regalado Montero, María Luz; Tosquella Angrill, Josep
This paper analyzes the lithostratigraphic features and the ostracode assemblages of the Upper Tortonian deposits located in the central sector of the Guadalquivir basin. Seven facies were defined, being deposited in fluvial to upper bathyal palaeoenvironments. Three main ostracode associations (infralittoral, circalittoral, upper bathyal) are defined, indicating a transgressive cycle throughout this period
Origen geológico de los contaminantes (sulfatos) presentes en las aguas subterráneas de la Laguna de Pétrola. (Albacete, España). Resultados preliminares
(Sociedad Geológica de España, 2003) Gómez Alday, Juan José; Castaño Fernández, Santiago; Sanz Mangas, David
The salty Lagoon of Petrola, 2 km2 in area, constitutes a representative example of the numerous closed basins that upholster the Iberian southern Subplateau. The lagoon is felt by several saline springs and wells which are placed around it. The brackish nature of its waters drives to the deposition of extensive evaporite deposits during the summer time when the lagoon dries completely. This saline water also imprints to the area a great environmental interest due to aquatic birds that lodge. Dissolved sulphate is one of the most important ions presents in groundwaters. In this study, the first results obtained for determining the sulphur and oxygen source in the groundwater sulphate molecule are presented
Nuevos datos tectono-estructurales del Macizo de Brovales (Antiforma de Olivenza-Monesterio): relación con el cabalgamiento de Monesterio
(Sociedad Geológica de España, 2003) Eguiluz, Luis; Carracedo Sánchez, Manuel; Sarrionandia Eguidazu, Fernando; Apalategui, Octavio
The Brovales Massif is a calckalcaline hercynian pluton intruded in Precambriam Serie Negra and clastic lower Cambrian sediment. Its emplacement has been suposed sinkinematic to the main hercinian fase. New structural and cartographic data reveals that this pluton has a central unit located in the norther area of the massif that shows a strong deformation with a generalised foliation N120°E-trending and dipping 30NE with a lineation N30°E, difining a generalised C-S structure. Cinematic criteria indicated top to the shouth thrusting. A second indeformed facies crop in the southern sectors and a thin level of metapelites and black quartzites to the Serie Negra Formation also afected by the same tectonic separate both facies. A hundreds meters thic shear zone with letf lateral movement deforms all granitic fades. The main thrust is considered to be the west prolongation to the Monesterio Thrust that shows similar kinematic. The Brovales Massif has been emplaced in more than one event and a more detailed cartographic work is needed
Morfología y evolución reciente del litoral entre Fnideq y M'diq (Tetuán, NE de Marruecos)
(Sociedad Geológica de España, 2003) Nachite, D.; El Moutchou, B.; Anfuso, Giorgio; Benavente, Javier; Bello, Emma; Macías Bedoya, Ana
A beach-monitoring program was carried in the Moroccan littoral between Fnideq and M'diq that forms a great physiographic. The present work deals with littoral morphology, recent evolution and relationships between littoral evolution and human actuations. In the period between 1937 and 1994, a homogeneous retreat rate of 2 m/year was recorded along the study coast. An opposite trend was recorded updrift of the main ports. Other human structures, such as villages, summerhouses, hotels, were built on the dune ridges, blocking the natural interchange of sediment between dune and beach
Las unidades litoestratigráficas del Jurásico Medio de la Cordillera Ibérica
(Sociedad Geológica de España, 2003) Gómez, J. J.; Fernández López, S.
Five lithostratigraphic units applicable to the different Middle Jurassic palaeogeographical elements of the Iberian platform system are proposed. For the oolitic-dolomitic belt developed in the Internal Castilian Platform, the Yemeda Fm is proposed. To the mainly dolomitic facies which extends over the El Maestrazgo High, the Rafales Fm is defined. Within the micritic external platform facies of the Castilian and Aragonese platforms, three formations have been recognized. The lower unit (El Pedregal Fm) is constituted of microfilament, mudstone to wackestone limestones. The middle unit (Moscardon Fm) is made up of biodastic and oolitic, grainstone to packstone limestones. The upper unit (Domeño Fm) represents a return to the external low energy wackestone to mudstone facies, locally containing patches of oolitic grainstone facies
Las bentonitas de Benavila (Portugal). Caracterización mineralógica y propiedades
(Sociedad Geológica de España, 2003) Dias, María Isabel; Suárez Barrios, M.; Prates, S.
The igneous massif of Benavila (Portugal) is constituted by rocks of granitoid nature, especially granodiorites associated to quartzdiorites, partially covered with palaeogenic sediments. A chemical, mineralógicaI and textural characterisation of clay materials deriving from weathering of those rocks has been done. Clays resulting of the weathered granodiorites of Benavila, are very rich in smectites. The X-ray diffraction (XRD) results of the bulk sample enhance the clayey characteristics of those materials, mainly associated to calcite, and traces of quartz and feldspars. A monomineralic clay sample has been chosen for a more detailed study. The clay fraction XRD results enhance the presence of only smectite, that is well crystallized and dioctahedral. A structural formula for this smectite of Benavila is proposed. The chemical analysis points to a Tatatila smectite type, relatively enriched in iron. The exchange cation capacity has been calculated in the bulk sample and in the < 2 pm fraction. The Specific Surface area has been evaluated in the 77°K nitrogen adsorption-desorption isotherms, applying the BET method. A porosity study has also been made through the t-curves. The results obtained with all those analyses are lower than the usually presented in literature
Implicaciones paleoclimáticas de la distribución geocronológica de espeleotemas en la Cueva del Cobre (Palencia)
(Sociedad Geológica de España, 2003) Muñoz, M. B.; Martín Chivelet, Javier; Rossi, C.
Twenty two Uranium-series datings carried on seven stalagmites collected in the cold, high mountain karstic system of Cueva del Cobre (Cantabrian Mountains, N Spain) allow to distinguish three phases of major growth frequency of speleothems in the cave for the last 7 50 ky. This difference in growth frequency is interpreted to be climatically induced: stalagmite growth was impeded during the coldest time intervals when the cave was probably covered by a mountain glacier and, on the contrary, their maximum growth took place during warmer humid episodes. This hypothesis is supported by the correlation of the speleothem growth frequencies with the oxygen isotopic stages of the late Quaternary
Geometría y distribución de facies en la cuenca paleógena de Zamora. Datos derivados de sondeos
(Sociedad Geológica de España, 2003) Guerrero Chamero, Olga; Corrochano, A.
The main goal of this paper is the study of the geometry and distribution of the units that made up the infilling of the southwestern basin margin. The drilling analysis and geological cross section define an eastern-western orientation of the axis basin, and deepening basement to the east and a some structural blocks with different deepening and trend, these latter are: the Corrales and Topas blocks are the shallowest, the Cuarena block is intermediate and Alaejos block is the deepest. They are limited by NNE-SSW, ENE-WSW, WNW-ESE fault systems. Five lithostratigraphyc units, these demostrates that fluvial-lacustrine sedimentation is controlled by the basin dinamics and the prograding alluvial fans that came from the basin margins: the Zamora Sandstones Formation, the Lutites Ehtrala Formation, the Corrales Sandstones Formation, the Aldearrubia Sandstones Formation and Molino del Pico Formation, can be distinguished
Geología del sistema de yacimientos de mamíferos miocenos del Cerro de los Batallones, Cuenca de Madrid
(Sociedad Geológica de España, 2003) Pozo Rodríguez, Manuel; Calvo, J. Pedro; Silva, P. G.; Morales, J.; Peláez Campomanes, P.; Nieto, M.
The Cerro de los Batallones (Los Batallones Butte) is located in the central-northern area of the Madrid Basin, central Spain. Six vertebrate localities containing a large variety of mammals together with amphibians, fishes and plant remains of Upper Vallesian Age (Late Miocene) have been found associated with the sediments forming the butte. From bottom to top, these sediments consist of magnesian lutite beds (Unit I), palaeosols formed of sepiolite and opal (Unit II), and siliclclastic, marlstone and carbonate beds (Unit III). Both the patch-like geometry and the composition of the deposits bearing the Upper Vallesian fauna indicate that their accumulation took place in cavities which acted as traps for both carnivores and herbivores. Although there is not conclusive evidence for the precise mechanism of formation of the holes, a combined effect of vertisol development followed by subsurface erosion processes ("pseudokarst") can be suggested as most reliable. Moreover, formation of the vertebrate localities of Cerro de los Batallones could provide some clues on the geological evolution of the Madrid Basin during the Upper Miocene
Geocronologia 207Pb/206Pb en cristal único de circón y Rb-Sr del plutón de la Cabrera (Sierra del Guadarrama)
(Sociedad Geológica de España, 2003) Casquet Martín, César; Montero, P.; Galindo, Carmen; Bea, F.; Lozano, R.
A Pb-Pb crystallization age of 302 ±3 Ma was found for the La Cabrera granite by the single zircon Pb-evaporation technique. Moreover the whole rock Rb-Sr isotope systematics provided an errochrone of 303 ± 24 Ma (I.R. = 0.709275; MSWD — 23.4). This age is Upper Carboniferous and is close to the end of a stage of regional N-S extension subsequent to the climax of Variscan regional metamorphism. The high MSWD of the Rb-Sr systematics might foe attributed to either an ubiquitous weak pervasive hydrothermal alteration or to the absence of initial isotopic equilibrium throughout the pluton. The second possibility is favored from Nd isotope composition considerations
Geochemistry of lower Paleozoic anorogenic basic rocks from the Evora Massif (Western Ossa-Morena Zone, Portugal)
(Sociedad Geológica de España, 2003) Chichorro, Martim; Santos, J. F.; Pereira, Manuel Francisco; Moita, Patricia; Silva, J. B.
Undated basic rocks included in the Ossa-Morena westernmost domains (Alentejo region, Portugal) have been studied in an attempt to fill the lack of geochemical data for the Evora Massif. The selected outcrops, interpreted to belong to the lower Paleozoic stratigraphic record, are mainly represented by amphibolites associated with metamorphosed detritic, carbonate and volcanic-sedimentary series. According to their petrography and variations of major, trace and REE elements, these basic rocks seem to derive from protoliths with tholeiitic basalt compositions probably related to an anorogenic geotedonic scenario controlled by transtension and the development of clastic and carbonate basin sedimentary sequences. Fractional crystallization of olivine, dinopyroxene and plagioclase may have played an important role in the generation of different melt composition, however, it is also necessary to invoke source heterogeneity and/ or different degrees of partial melting of a mantle source with garnet Iherzolite composition to explain the observed range of incompatible trace élement ratios. The most likely sources of the basaltic melts may have varied from dgpletgdl mantle (similar, to N-MORB sources) (o mantlerocks affected

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