Geogaceta -- Nº 20-5, (1996)

Permanent URI for this collectionhttps://hdl.handle.net/10272/12412

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Vulnerabilidad y factores condicionantes de la erosión en la cuenca del río Guadalfeo vertiente al embalse de Rules (Granada)
(Sociedad Geológica de España, 1996) Castillo, A.; Martín Rosales, Wenceslao; Osorio, R.
The Universal Soil Loss Equation (U.S.L.E.) is used as a criteriaou to measure erosive vulnerability in the basin of the dam at Rules (Granada). The area was discretized by subdivision into 20 hydrologic units. This paper presents a map of vulnerability to erosion. It also considers the main factors determining erosion and possible action to be taken. The conclusions reached might be applicable to other Mediterranean basins of similar geomorphological characteristics and land use (e.g. Adra, Andarax and Almanzora)
Variations in the Mediterranean thermohaline circulation during the Last Glacial/Interglacial transition (20 Ka PB), based on a dinocyst record of the Alboran Sea
(Sociedad Geológica de España, 1996) Tarragona, J.; Canals, M.; Alonso, Belén; Cacho, Isabel
The dinoflagellate cyst assemblages in a core from the Western Alboran Sea, in the upwelling domain off Malaga, show a record of marine environmental change for the Late Glacial and Holocene periods. The dinocysts are good indicators for changes in sea surface productivity. Productivity changes, in the Western Alboran Sea, relate to upwelling intensity. The environmental change based on this record allowed to link and time the responses of the oceanic circulation to climate. Results indicate that upwelling was present over the last 20 ky. It was weakened during brief periods suggesting a weaker thermohaline circulation and a lowered E-P budget. Enhanced upwelling occurred between 14.5-12.6 ky BP, suggesting an intensification of the thermohaline circulation and pointing to the conclusion that on a long term, the main forcing of the Mediterranean circulation was thermohaline, not relative sea-level changes
Un modelo sobre el control orbital de la sedimentación en medios de plataforma: el Albiense-Cenomaniense del Puerto del Remolcador (Maestrazgo, Castellón)
(Sociedad Geológica de España, 1996) García Hidalgo, J. F.; García, A.; Segura, M.
There are marry papers dealing with orbital forcing on sedimentation, mainly on deep facies. The study of orbital forcing on platform sediments, however, depends on the development of accurate models, which can be contrasted with sediments. A cyclic model on the superimposition of three different orders of sedimentary cycles has been elaborated to explain sedimentation in the Upper Albian - Cenomanian times in the Iberian Ranges, and it has been used in order to check the Puerto del Remolcador section looking for orbital forcing signals. The model allow the determination of the different cycles duration (1,2 m.a, 240 ka and 48 ka), which is close to those of orbital forced cycles, mainly with the 41 ka obliquity cycles. Using the duration of the cycles, both the temporal extension of the distinct lithostratigraphic units and the sedimentary rate of limestones and marls can also be estimated
Sedimentación lacustre y ciclicidad: las sucesiones fluvio-lacustres del Oligoceno superior del sector SE de la cuenca del Ebro
(Sociedad Geológica de España, 1996) Barberà, X.; Cabrera, L.; Marzo, M.; Ripepe, M.
A cyclostratigraphic study of Late Oligocene fluvio-lacustrine and lacustrine sequences was carried out in the Ebro basin. Fourier spectral analysis was used to analyze four stratigraphic and sedimentological parameters (thickness, colour, lithology and an estimative depth index) and was proved the appearance of periodicities of 39 and 16 to 18 ky which approximately fit the 41 ky (obliquity cycle) and 19 ky (short precession cycle). In all spectra, the obliquity cycle is a strong signal in the lacustrine intervals, but in fluvial intervals the ciclycity was concealed, likely as a consequence of overprinting of tectonic influence
Rocas y minerales industriales de Catalunya. Los áridos graníticos y basálticos del ámbito territorial metropolitano. Aspectos S.I.G. del proyecto
(Sociedad Geológica de España, 1996) Paz, A. de; Marturiá, J.; Barberà, M.; Pascual, C.; Palau, J.
We show a CIS (Arc-Info) methodology, and the guidelines to build alpha-graphic data bases, which have been used in this project. The main result was to obtain a Map of Suitable Areas, in which different aspects are considered as: i) the resource exists, ii) the resource has a minimum quality and Hi) territorial planning constraints. Therefore, the resultant map (similar to a resource map) is obtained by the intersection of the following maps: Map of Lithotectums, Map of the Areas with Potential Interest and Map of the Territorial Planning.
Resultados paleomagnéticos preliminares en el vulcanismo neógeno de la Sierra de Las Cruces (Valle de México, México)
(Sociedad Geológica de España, 1996) Osete, M. L.; Ruiz, V. C.; Caballero, C.; Urrutia Fucugauchi, J.
A palaeomagnétic study have been carried out on the western margin of the México basin. 24 sites from Sierra de Las Cruces were sampled and analyzed in the laboratory. A total amount of 237 samples has been fully demagnetized and a simple directional magnetic behavior was observed in all samples. The mean direction obtained in this study is D = 3 5 3 .1 1=31.6 ( N = 2 4 K = 2 8 .9 a 9 5 = 5 .6 ), in agreement with the expected direction. Therefore this area has not been affected by significant block rotations in contrast to the counterclockwise rotations observed in the easternmost sector of the Transmexican Volcanic Belt (TMVB), towards the Gulf of México, and in its centrahwestem part. In addition a magnetic zonation has been observed covering at least the Matuyama and Gauss polarity chrons
Restauración de impactos mineros en zonas semiáridas: el ejemplo de la provincia de Granada
(Sociedad Geológica de España, 1996) Ferrer Modolell, A. E.
Quarries reclamation has been efective since 1982 because of environmental mining laws. Reclamation techniques have been developed quikly during these years. In Grenade province, quarry reclamation is especially dificult because of the climate. In semiarid areas revegetation techniques are more or less unuseful and erosive/desertitation processes are the main enviromental matter. In fact, geomorphological and topographical remodélation and dust preservation are the most useful reclamation techniques applied over these area
Propuesta de un modelo cronológico para las terrazas de los ríos de la vertiente cantábrica
(Sociedad Geológica de España, 1996) González, A.; Díaz de Terán, J. R.; Barba, F. J.; Remondo, Juan; Cendrero, A.
A new fluvial terraces chronology Is proposed for the rivers in northern Cantabrian Range. Six terrace levels were identified and mapped. These have average heights of 2,5; 10; 15; 20; 35; and 63 m above river level. Four older surfaces were identified at 125, 250, 600 and 800 m above these terraces. The new ages place the Pleistocene terraces at 35 m above the fluvial channel. A discussion ab o u t the accuracy o f the ages is presented
Preliminary magnetostratigraphic data of a Tatarian (Upper Permian) section on the Volga river (Russia)
(Sociedad Geológica de España, 1996) Gialanella, P. R.; Heller, F.; Haag, M.; Nurgaliev, D.; Jasonov, P.; Khasanov, D.; Ibragimov, S.
A magnetostratigraphic profile of the uppermost Tatarian (Upper Permian) of a section of continental sediments from Eastern Platform is presented. Around 300 samples across an Upper Permian sequence o f red beds Monastirskoje on the Volga River Valley (South-West of Tatarian, Russia) have been collected. The characteristic primary component defined nearly for all the examined samples has a normal as well as reversed polarity, therefore a clear polarity zonation Is defined. The fold test, carried out on samples collected In the nearby section of Titjuschin where the sediments are exposed in a fold structure, indicates that the characteristic magnetization pre-dates the folding
Principales impactos antrópicos en la Gruta de las Maravillas (Aracena, Huelva)
(Sociedad Geológica de España, 1996) Martín Rosales, Wenceslao; Pulido Bosch, Antonio; López Chicano, Manuel; Rodríguez Navarro, C. M.; Vallejos, Ángela
The cave of Marvels has been the object of a detailed study since 1993 which has allowed us to identify the main effects deriving from tourist visits and human activity on the environment. Although the deterioration is by no means irreversible, it should be noted that there are noticeable effects on the subterranean water occupying part of the cave on the air, with an appreciable rise in temperature and carbon anhydryde content and reduction in humidity, and on the rock, with evident growths of algae, lichens and fungi
Patrimonio del Museo de Salobreña (Granada): I descripción y estudio de cerámicas arqueológicas romanas
(Sociedad Geológica de España, 1996) Muñoz Pascual, I.; Andrés Huertas, A.; García Ramos, G.
Recently, the rapid destruction of the cultural heritage of Salobreña-Spain, due to an anthropic action, led to the people of the city to create a Museum for studying its archaeological artefacts. Several roman ceramic pieces have been selected by their archaeological interest, in order to establish their local or foreign origin in appearance to local raw materials, using FRX, EDX-SEM and DRX. The local origin of the main part of the archaeological ceramics indicate the great importance of Salobreña during the roman period as a cultural and economical center
Patología de monumentos por técnicas de proceso digital de imágenes
(Sociedad Geológica de España, 1996) Ángel Martínez, M. C.; Martínez Murciano, J.; Rodríguez Mateos, F.; Nieto, J. M.; Prendes Rubiera, N.
The forms of degradation presented in the “Ermita de la Bureba" are identified and morphologically studied, using digited images. A metodology is proposed in order to discriminate alveolar weathering, striations, disgregations, etc., in the binary image, obtained by digital processing and using the expertly sifting algoritm . The new image produce information on the morphological properties of this alteration
Paleomagnetismo y deformación reciente en la zona interna de las Béticas orientales
(Sociedad Geológica de España, 1996) Calvo, M.; Vegas, Ramón; Osete, M. L.
A paleomagnetic and rockmagnetic study was carried out on rocks from 33 volcanic and 12 sedimentary sites of Serravalian/Tortonian to Pliocene/Quaternary age in the internal zone of the eastern Betic Cordillera. After comparing paleomagnetic results with the expected Pliocene/Miocene direction, rotated and unrotated areas could be recognized, rotations being clockwise and counterclockwise. Very large rotations could be found in some cases. In the Cabo de Gata region, adjacent blocks rotated in opposite senses could be recognized. Block rotations in the internal zone of the eastern Betic Cordillera are non-system atic and related to the m ovem ent o f faults as local responses to the late Miocene-Present regional stress field
Oscilaciones del nivel del mar de largo y corto plazo: indicadores morfosedimentarios en zonas costeras
(Sociedad Geológica de España, 1996) Dabrio, Cristino José; Zazo, C.; Somoza, L.; Goy, José L.; Bardají, Teresa; Lario, J.; Silva, P. G.
Sampling for dating coastal units and quantifying processes is only possible and rewarding after detailed mapping and morphosedimentary analysis. The study of Last and Present Interglacial deposits in the Iberian Peninsula reveals that there are short-term sea-level oscillations superimposed to longerterm periodicities. Although short-term periodicities, as those observed in spit-bar units, are vital for coastal management, longer-term changes should not be discarded
Nuevos datos sobre la estratigrafía del relleno cuaternario de la depresión de Comeya (Picos de Europa, Asturias)
(Sociedad Geológica de España, 1996) Farias Arquer, Pedro; Jiménez Sánchez, Montserrat; Martínez, Jorge
Two core-holes have been drilled in the Comeya alpine graben in order to obtain new data about the stratigraphycal characteristics of the sedimentary fill of the basin and to check its geometry, previously deduced by geophysical research. Available data show that the sedimentary evolution of the basin is related to the existence of two alluvial systems with their fronts resulting in a proglacial lacustrine environment. The ancient lake has been progressively filled evolving to a peat deposit at the beginning of the Holocene. At presently, the peat deposit as well as the alluvial system located in the SE are still active.
Neoformación de sales en la piedra monumental de la Ciudad de Zamora
(Sociedad Geológica de España, 1996) Añorbe Urmeneta, M.; Sáinz de Cueto, F. J.; Martín Pozas, J. M.; Díez Torres, J. A.
In this paper special focus is placed on the neoformation of salts (gypsum, halite, calcite, dolomite and calcic oxalates) and stone deterioration mechanisms concerning the main historical monuments of Zamora (Spain). Several measuring techniques and assessment methods are been developed. Some explanatory attempts about the neoconstituent compounds causality are proposed.
Migraciones intercontinentales y eustasia: el datum de Hipparion
(Sociedad Geológica de España, 1996) Garcés Crespo, Miguel; Cabrera, L.; Agustí, J.; Parés, J. M.
The magnetostràtigraphic study of vallesian sites in the Vallès-Penedès Basin (NE Spain) provides a reliable dating of the earliest appearance of Hipparion at 11.1 Ma. Good agreement with radiometric ages from other sites in Central Europe and Turkey suggests an isochronous dispersal o f this eq uid throughout the Mediterranean region. A possible isochrony at a larger geographical scale (Eurasia and Mesogea) is not ruled out, but must await more reliable ages of other Hipparion first appearance records in Asia and Africa
Medidas del transporte de nieve por el viento en el Pirineo oriental catalán
(Sociedad Geológica de España, 1996) Mases, M.; Martínez, H.; Vilaplana, J. M.; Font, D.
During three winter seasons an experimental plot was monitored in order to study the snow wind transport. This plot is located in La Molina ski resort (Eastern Pyrenees). This transport is studied using the laws of fluid mechanics and the boundary layer theory. The experimental concentration profiles are compared with the theoretical ones.
Magnetoestratigrafía del Neógeno del sector central de la Cuenca del Duero
(Sociedad Geológica de España, 1996) Ruiz, V. C.; Mediavilla López, Rosa; Osete, M. L.; Villalaín, Juan José
Several biostratigraphic studies have been carried out on lacustrine and fluvial-lacustrine sediments in the neogene Duero Basin, these show that most of the outcrop depositional sequence belongs to the Aragonian - Upper Vallesian. Howewer, the age of neogene sedimentary infill is still unknown. For this reason, a magnetostratigraphic study have been carried out on four sites (Torremormojón, Jariego de Cerrato, Tortoles de Esgueva y La Miranda) in order to stabllsh magnetostratigraphic correlations between them. Samples were step-wise thermally demagnetized, susceptibility was measured after each heating step, and experiments of incremental acquisition of isothermal remanence were carried out. Samples present a low intensity of the natural remanent magnetization (NRM) and viscous and / or chemical secondary components. In spite of this, most of the cases the polarity of the primary component has been identified and the tale magnetostratigraphic logs have been obtained in each site. These logs have been correlated with the geomagnetic polarity timescale, and some magnetozones have been dated. The investigated sediments.have an age ranging from 7.3 to 11.4 m.a.
Magnetoestratigrafía preliminar de los materiales pliocenos de la Cubeta de Villarroya. (Sierra de Cameros, La Rioja)
(Sociedad Geológica de España, 1996) Pueyo Morer, Emilio L.; Muñoz Jiménez, Arsenio; Parés, J. M.
In this work we report a magnetostratigraphic study of a Pliocene section at Villarroya basin. The correlation with the Geomagnetic Polarity Time Scale (GPTS) is tied by the existence of a well-defined paleontological locality (M N 1 6 b ) at the top of the profile . This correlation allows us to calculate sedimentary rates which satisfactorily match the expected rates from local paleogeographyc studies. The main contribution of this study is the precise magnetostratigraphyc dating of both the Villarroya paleontological locality at Reunion magnetozone (2,229-2,197 m.y.) and, specially, the climatic sedimentary break (3,325-3,221 m.y.) which occurred at the boundary of the two. identified TectoSedimeptary Units (TSU).

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