Geogaceta -- Nº 28, (1999)

Permanent URI for this collectionhttps://hdl.handle.net/10272/9841

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Un nuevo yacimiento jurásico con icnitas saurópodas en la Cordillera Ibérica. Calve (Teruel)
(Sociedad Geológica de España, 1999) Blanco, M.; Caro Calatayud, S.; Pérez Lorente, Félix; Requeta, E.; Romero, M.
This paper describes a new dinosaur footprint site found in Galve, Teruel. It is located in the transition zone between the Higueruelas and Villar del Arzobispo formations. According to geological studies, the Higueruelas Formation and the lower part of the Villar del Arzobispo formation are Upper Jurassic, meaning that these prints are also from that period. The morphology of the asemblage displays characteristics that identify the ichnites as sauropods, probably of the Brontopodus ichnogen. The tracks illustrate the passage of a sauropod group, maybe a herd, over tidal flats
Tectónica extensional en el Sistema Central: La Zona de Cizalla Dúctil de Santa María de la Alameda (Madrid)
(Sociedad Geológica de España, 1999) Capote, Ramón; Martín González, Fidel; Tsige, Meaza
The Santa Maria de Alameda (Madrid) Ductile Shear Zone is a complex mylonitic belt trending east -West and dipping 30°-60° southward. The hanging wall block sinks towards the South-Southeast. Its kinematics is in relation to an extensional tectonic regime with North-south stretching direction. This large structure belongs to the early stages of the Malagon tectonic period, where important faulting and dike emplacement were produced. The shearing process was developed in retrograde metamorphic conditions in a wide range of temperature, which goes from 400° C to 150° C. The age of this deformation is constrained by the variscan regional metamorphic peak and the intrusion of late variscan granitoids (Las Navas del Marques adamellites), being therefore, between early Namurian and Stephanian
Riesgo Sísmico en La Depresión de Guadix-Baza (S España)
(Sociedad Geológica de España, 1999) Martín Rojas, Iván; Díaz Hernández, J. L.; Martín Vallejo, M.; Julià, Ramón
Sinuosity, Facetation percentage, disectation percentage and width/high valley ratio geomorphic parameters are applied to the Alicun Spa resort mountain front. This front, defined by a normal fault, shows several springs originated during the Quaternary. Travertine deposits are related to the springs and the fault The travertine ages are correlated with the values from the geomorphic parameters, in order to obtain seismic risk information
Relaciones entre fallas y sismicidad en el noroeste peninsular
(Sociedad Geológica de España, 1999) González Casado, J. M.; Giner Robles, J. L.
The statistical study of the post-hercynian cartographic faults of the Northwest part of Spain (Galicia) allow to precise the existence of three main fault sets; NE-SW, NW-SE and N-S, which controlled the topograpic features in this area. The seismic epicentres in this region are related mainly with the NE-SW and N-S fault sets, which are, probably, the seismogenetic faults. The orientation of the stresses responsible for the seismic activity been deduced from the analyses of 76 earthquake focal mechanisms. The maximum horizontal compression direction is located NW-SE, then the NE-SW faults move as reverse faults, the NW-SE set as normal faults and the N-S as normal-oblique faults (sinistral)
Procesos degradativos en antiguas superficies grabadas sobre granitos: Indicadores de magnitud y patrones de estado
(Sociedad Geológica de España, 1999) Uña Alvarez, E. de; Vidal Romani, J. R.
This paper analyzes the so called, (pilas, gnammas, vasque, etc.), small concavities that retain the water of the rain/ runoff that develops etching processes. Some authors support the beginning of the form already undersoil/ regolith, though all recognize the main development of the form in subaerial environment. The chemical weathering by water increases the size of the pias (pilas, gnamma, vasque), much greater when older is the surface over it develops. Any process that stop the normal evolution (burial, erosion, etc.) can modificate the relative age of the host surface that will be demonstrated younger than in reality is. The size parameters defined by statistic analysis of this measures has a relative chronological value since demonstrate the relationship among evolution of the form and the age of the surface.In this work is presented the analysis of evolution of pias (gnammas, pilas, vasque), of different surfaces developed with a chronology topografically successive to the one which can be assigned also an absolute chronology (by cosmogenic isotopes) that it has been used to know the generation age of the form
Petrografía, procedencia y alterabilidad del material pétreo utilizado en la construcción del Monasterio de San Millán de la CogoIIa, Yuso (s.XVI-XVIl), La Rioja
(Sociedad Geológica de España, 1999) García Garmilla, Francisco; Zalbide, M.; Rodríguez Maribona, I.; Cano, M.
A catalogue of the stone material employed for the construction of the San Millán de la CogoIIa Monastery (Yuso) has been undertaken. The characterization of the rocks has enabled us to explain the provenance of the most part of the stones from several quarries very close to the monastery. We have also compared the different degree of alteration of the stone material. Whereas the brecciated limestones from Jurassic age employed for the construction of all the main walls and columns of the monastery, have a very resistant behaviour to weathering, the Tertiary sandstones and coarse-crystalline evaporites (gypsum) were destined to archs, archivolts, cornices and ornamental pieces and appear largely affected by dissolution processes showing a high degree of decomposition, particularly in the northern and western façades of the building. The evaporitic material has been specially conflictive with respect to the restoration works carried out the last year on this historic monastery
Nuevas acotaciones al alcance del método de datación por análisis de racemización de aminoácidos. Sección de Cuesta Colorada (Almería SE de España)
(Sociedad Geológica de España, 1999) Torres, Trinidad de; Soler, Vicente; Ortiz, José Eugenio; Llamas, F. J.; Canoira, L.; García de la Morena, M. A.; Civis-Llovera, Jorge
New data about the age of Cuesta Colorada (Almería, Spain) are presented. Evidency from micropaleontological sampling and new palaeomagnetical studies, allowed us to correlate the almost whole section with the I and II Pliocene Units. An undoubtfull palaeomagnetical reversal found in an intensively sampled micritic layer, could represent the Causs-Matuyama boundary, confirming the data from amino acid racemization analyses which indicate a wide time span between both the bottom and the top of Cuesta Colorada deposition time. Samples taken from a very deeply excavated road cut allowed very well preserved amino acid and palaeomagnetic samples taking, being possible to enlarge the normal amino acid dating method range which in very favourable conditions could reach the upper part of Lower Pleistocene time
Materia orgánica y diagénesis de la formación de margas del Mas d'Ascla (Jurásico superior) en la cuenca del Maestrazgo (Cadena Ibérica oriental)
(Sociedad Geológica de España, 1999) Permanyer, Albert; Marfil Pérez, Rafaela; Salas, Ramón; Peña, J. A. de la; Dorronsoro Urrutia, C.; Rossi, C.
The Mas d'Ascla marls Fm. (Upper Kimmeridgian to lowermost Tithonian) in the Maestrat Basin (Salzedella sub-basin, Castellò de la Plana) displays two organic-carbon-rich horizons which indicate anoxic conditions. The maximum anoxic event is located at the base of the formation corresponding to the lower part of the trangressive system tract. In both horizons the kerogen is mainly of marine origin with algal and amorphous sapropelic organic matter, a low organic carbon content (0.5% - 1.26%) and a low potential yield of hydrocarbons (HC). These data and the Tmax. suggest a mature source-rock which has already generated nearly all HC. Extractable organic matter is fundamentally composed of asphaltenes and resins predominating over saturate and aromatic compounds which have been probably expulsed out of the source rock
Mamíferos de las terrazas del valle del Tajo: primeros datos de micromamíferos del Pleistoceno en Toledo (España central)
(Sociedad Geológica de España, 2000) Sesé, C.; Soto, E.; Pérez González, Alfredo
This paper deals with the first data on small mammals from Buenavista Inferior and Salchicha Inferior, two new sites on the Tagus river terraces in the area around Toledo. The authors also undertake a synthesis on the large mammals from the classical sites of this area. Biostratigraphically, the oldest mammal site is Salto de la Zorra (on the TT6 terrace, at + 75m) correponding to the Lower Pleistocene. The Valdelobos Superior site (TT7 terrace, at +60m) can be placed on the transition from the Lower to the Middle Pleistocene. The following sites: Poligono Industrial of Toledo, Campo de Tiro, Buenavista Inferior and Salchicha Inferior, placed on the TT9 terrace (at +40m), correspond to the Middle Pleistocene. The Pinedo site, placed on the TT10 terrace (at +25-30m), also belongs to the Middle Pleistocene but with a more recent age than the aforenamed sites. Finally, the Arenero de Valdelobos site, placed on the TT12 terrace (at +4-9m), corresponds to the Upper Pleistonce. Almost all the mammal associations from these sites of the Lower and the Middle Pleistocene suggest an environment with some wooded areas and also some open areas. The climate would be mild. From the Middle Pleistocene, only the more recent mammal association of Pinedo suggests a more wooded environment or at least with more vegetation, and a relatively warmer and more humid climate than the actual in the Meseta. Finally, the Upper Pleistocene Arenero de Valdelobos mammal association is characteristical of steppe
Las unidades alpujárrídes y maláguides entre Cabo Cope y Cabo de Palos (Murcia, España)
(Sociedad Geológica de España, 1999) García Tortosa, F.J.; López Garrido, Ángel Carlos; Sanz de Galdeano, Carlos
According to their stratigraphic characters and tectonic positions, the Alpujarride units existing in this area are reduced to three units "type" that, cited from bottom to top, are: Peñas Blancas, Cabo Tiñoso and Portman units. This last type of units show a clear intermediate character between the Alpujarride and Malaguide complexes. There are two Malaguide units in this area, that of Los Simones, in the eastern part, and that of Cabo Cope, in the western part
Las metamorfitas de Cumbres Calchaquíes, Tucumán (Argentina) y sus texturas deformacionales
(Sociedad Geológica de España, 1999) Omil, M.; Bobovnikov, J.
Phyllonites which crop out in the northeastern part of Cumbres Calchaquies are the result of regional metamorphism, greenschist facies, with additional cattaclastic metamorphism. They have characteristic deformational textures developed in the ductile and brittle fields, and blastic textures in lesser degree. This textural coexistence is interpreted as the result of polydeformation, with variable physical and chemical characteristics, while the temperature remained in the biotite isograde, according the observed mineral paragenesis
La caída del meteorito Cabezo de Mayo al sur de Murcia en 1870
(Sociedad Geológica de España, 1999) Alcalá, Luis; Martín Escorza, Carlos
Three meteoritic events in the Region of Murcia have provided materials which are housed, among other places, at the Museo Nacional de Ciendas Naturales. They come from the falls of Molina de Segura (1858) and Cabezo de Mayo (1870), as well as from the find of Los Martinez (1894). This work aims at updating the information related to the meteorite of Cabezo de Mayo, including the presentation of a map - where the landing places are marked - sent to the Museum in 1871 and kept in its archive
Hidrogeoquímica convencional e isotópica de las aguas carbónicas de Cataluña
(Sociedad Geológica de España, 1999) Redondo, R.; Yélamos, J. G.
Conventional and isotopic hydrogeochemical techniques have been applied to a study of CO2-rich waters in the northeast of Catalonia. Two hydrogeochemical facies, a calcium-bicarbonate and another sodium-bicarbonate are clearly distinguished. The second one seems to be the result of evolution from the calcium facies. The tritium-ages support the previous division in two hydrogeochemical facies. Measurements of ,sO and deuterium ratio indicate that the carbonic waters have a meteoric origin. The i3C/12C ratio varied from -5,0 to -0,64 6°/œ showing a deep origin of CO
Hidrogeoquímica de las aguas minerales de la Península Ibérica
(Sociedad Geológica de España, 1999) Moratilla, P.; Yélamos, J. G.
One hundred and fifty-five different Spanish mineral water analysis have been assessed in order to study the hydrochemical facies and ground-water patterns of evolution. After identifying which type of aquifer belongs each one of the analyses, these have been classified in six lithological groups. The analysis of this data base indicates the following conclusions: 1) as was to be expected, salinity is related to the solubility of aquifer lithology, but the set of maximum values of total dissolved solid is found in C02-rjch waters, 2) it does not seem to exist chloride-sulphate hydrochemical facies with low bicarbonate concentration, neither sodium-magnesium fades with calcium equivalents lower than 20 % and 3) the pathway of chemical evolution for ground water is not sp simple as the classic series of Chevotarev, or at least, they appear several different patterns in function of the lythological groups; thus, gro.und water in hard rocks changes from calcium-bicarbonate water to sodium-chloride facies, or there are two independent patterns of change in the lythological group formed by. gypsum and salt
Geoquímica orgánica de las lutitas lacustres de las cuencas cenozoicas del Duero y Ebro
(Sociedad Geológica de España, 1999) Lucini, M.; Torres, Trinidad de; Llamas, F. J.; Canoira, L.; Ortiz, José Eugenio; García de la Morena, M. A.
Biomarquer analytical results from Cainozoic age organic rich lutites from Duero and Ebro basin drill holes are presented. The presence and abundance of n-alkane, n-metil ketones, n-etil-ketonés, n-butil ketones and elemental sulphur are compared. Samples from Ebro basin bore hole core (PE-1) reveal alternances of "terrestrial" and "acuatic" lacustrine environmental conditions (shallowing versus deepening conditions) while samples from Duero basin borehole core (VS-1) show a constant "terrestrial (shallow) character
Geometría del granito de La Bazana a partir de datos gravimétricos (Zona de Ossa-Morena, Macizo Ibérico)
(Sociedad Geológica de España, 1999) Galadí, E.; Galindo Zaldívar, Jesús; Simancas Cabrera, J. F.; Expósito Ramos, Inmaculada
The La Bazana granite is a small intrusive pluton located at the hinge of a symmetrical late Variscan antiform. This granite intrudes essentially in Cambrian metapelites and metasammites of the Ossa-Morena Zone. The attitude of foliation in the host rock, as well as the anisotropy of magnetic susceptibility data and the magmatic foliations and lineations in the granite, indicate that the upper part of the pluton has a dome shape. The gravity study suggests that the granite extend in depth until near 10 km and has an inverted drop shape with a certain laccolithic tendency. While the ascent of this granite has been probably of diapiric type, in the final stages the top of the diapir has extended laterally
Existencia de una discordancia angular con laguna de Albiense medio en el Complejo Urgoniano de Ranero (Ramales-Karrantza, región vasco-cantábrica)
(Sociedad Geológica de España, 1999) López Horgue, Mikel A.; Aranburu Artano, Arantza; Fernández Mendiola, Pedro Ángel; García Mondéjar, Joaquín
The Albian carbonate platform of Karrantza (Bizkaia, N Spain) displays an important angular unconformity whose corresponding lacuna encompasses most of the middle Albian and the lowermost part of the upper Albian. This lacuna is established on biostratigraphic basis in the platform interior domain, and extends with decreasing magnitude towards the basin. Synsedimentary block tilting is envisaged to explain differential subsidence and the origin of the unconformity
Evolución sedimentaria del polder Anbeko (Reserva de Urdaibai, Golfo de Vizcaya) durante el Holoceno
(Sociedad Geológica de España, 1999) Pascual, Ana; Weber, O.; Rodríguez Lázaro, Julio; Jouanneau, J. M.
The sedimentology and micropaleontological content (benthic foraminifera) of a core located in the Anbeko polder of the Urdaibai estuary (Southern Bay of Biscay) have been analysed in order to characterize the holocene evolution of this polder. Based upon sedimentology and micropalaeontological assemblages, four units have been identified in this core. During the first phase this area was under marine conditions, with a a maximum marine influence around 5000 years BP. The pulsation described during the Atlantic-Subboreal transition of the Holocene is then registered in this core. Sedimentological facies of the second unit indicate a decrease of energy in this environment, where outer estuarine foraminifera dominated the assemblages. The third phase indicates the progressive filling of the estuary, with the appearance of a vegetated marsh, as evidenced by the total dominance of agglutinated foraminifera. This marsh, which is progressively isolated from the tidal influence, was anthropologically transformed into a polder during the 1 8th. century
El Magmatismo Básico en La Cuenca Fameno-Dinantiense de Sidi Bettache (Marruecos Hercínico Noroccidental): Nuevos Datos
(Sociedad Geológica de España, 1999) Lakhloufi, A.; Hamoumi, N.; Saquaque, A.; Aarab, A.; Jermouni, A.
Commonly is held up that the Sidi Bettache Basin corresponds to the collapse of a large block of the middle Devonian carbonate platform with subsequent magmatic injections emplacement along its boundaries. Previous studies of one of us (A.L.) and those in progress show instead that this magmatism is primarily controlled by distensional activity of NNW-SSE to NW-SE faults before Middle Visean time. These faults affect throughout the 60 km wide western part of the basin which is also characterized by its Famennian-Lower Visean sedimentary evolution and by a complex variscan polyphasic structuration
El levantamiento Tortoniense-Cuaternario de Sierra Nevada (Granada, España): Fenómenos de tectónica gravitatoria en su borde occidental
(Sociedad Geológica de España, 1999) Sanz de Galdeano, Carlos; López Garrido, Ángel Carlos
The former Alpujarride nappes at the western margin of Sierra Nevada are strongly affected by gravitational collapse phenomena, with significant thinning of their original thickness, creation of new detachment surfaces and folds and faults, all forming approximately a fan-like pattern that flank this border of the sierra. These types of deformations disappear immediately out of the W border of Sierra Nevada and consistently are in a good part attributable to the considerable uplift that Sierra Nevada undergone, especially since the late Tortonian

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