Geogaceta -- Nº 20-6, (1996)

Permanent URI for this collectionhttps://hdl.handle.net/10272/12413

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Volcanogenic mercury pollution in the ground water system of La Palma, Canary Islands, Spain
(Sociedad Geológica de España, 1996) Pérez, N. M.; Hanor, J. S.; Means, J.; Álvarez, C. E.; Hernández Moreno, J. M.
Mercury measurements in groundwaters from La Palma, Canary Islands, revealed high Hg levels (up to 1500, pg/L) in some portions of the volcanic aquifer. This Hg pollution does not seem to be related to anthropogenic activities; therefore, a volcanogenic origin might be a potential Hg source
Utilización de testificación geofísica en la clasificación geotècnica de las facies detríticas de la cuenca de Madrid
(Sociedad Geológica de España, 1996) Fernández Fuentes, I. M.; Cuéllar Mirasol, V.
This paper sets the relationship between geophysical parameters and geotechnical properties of the detritic materials from the Madrid Basin. The geophysical parameters have been obtained from geophysical logging made in twenty seven boreholes. The geophysical parameters Natural Gamma-ray and Conductivity have been selected in this research due to their direct relationship with some soils index properties (granulometry, plasticity). The regression coefficients obtained in this study justify the possible use of geophysical logging to classify the grounds from a geotechnical point of view
Un precedente en 1962 de los congresos geológicos de España
(Sociedad Geológica de España, 1996) Truyols, J.
In 1962 the First National Meeting of Geology took place in Oviedo. This was, up to a certain point, a precedent of the present day Geological Congresses of Spain. The most interesting part of the meeting was the debate on the problems brought to light by the Cantabrian Palaeozoic Geology
Un ejemplo de geología colonial: el reconocimiento de las islas de Panay (Filipinas), por Enrique Abella y Casariego
(Sociedad Geológica de España, 1996) Ordaz, Jorge
The survey of Panay island in the Philippines, carried out by the mining engineer Enrique Abella y Casariego between 1 885 and 1890, has been taken as an example of the geological studies in these islands during the last century. The late development of this type of studies are explained by political and economical reasons, as well as the special characteristics of the Archipelago
Una base de datos sobre las comunicaciones presentadas en los simposios I a VIII de enseñanza de la geología (1981-1994)
(Sociedad Geológica de España, 1996) Lillo Bevia, J.
It has been designed with CLIPPER a simple data base that operates with an alone window. In this window is shown a bibliographical chip with its fields and function keys. In spite of its simplicity is very potent because the introduced data can be handled from D BASE III + in MS - DOS , or well in WINDOWS environment, from ACCES or any other data base that recognize files *.dbf. The base collects the communications presented in the eight Teaching Symposia of the Geology celebrated from 1981 to 1994 in Spain
Una aplicación didáctica en "Cartografía Ambiental y Ecológica": propuesta de reforestación con criterios ambientales
(Sociedad Geológica de España, 1996) García-Abad Alonso, J. J.; Moreno Sanz, F.
Making, using and interpreting maps is necessary in Environmental and Earth's Sciences. This paper shows the foundations and methodology to realize an exercise proposed to universitary students of the matter «Environmental and Ecological Mapping» (Studies of Sanitary and Environmental Biology. University of Alcalá de Henares. Spain). The aim of the exercise is the hypothetical afforestation on Trijueque Area (Province of Guadalajara. Central Spain)
Sismicidad inducida por embalses. Análisis del efecto de carga
(Sociedad Geológica de España, 1996) Herráiz, M.; Lindo, R.
Publications on Reservoir Induced Seismicity (RIS) in Spain are very scarce in spite of the remarkable importance that the problem can reach in the country. This communication describes its main characteristics and presents a computer program which calculates the incremental stress due to a water load (e.g. a reservoir). The program is based on Cough's methodology and assumes a two-dimensional geometry. An application to the Entrepehas reservoir area is also shown with the purpose of testing the usefulness of this program
Simulación física y numérica de las avalanchas de nieve en Francia
(Sociedad Geológica de España, 1996) Naaim, M.; Martínez, H.
In this paper are presented and described the main characteristics of the different kind of snow avalanches. We distinguishes two great families : dense and powder avalanches. Their releasing conditions are reminded and their dynamics and effects are described. A modelling based on Saint Venant equations (completed by a Bingham reological model) is proposed for the dense avalanches. Concerning powder avalanches their similarity with gravity currents allows to undertake a physical modelling. This physical modelling is succinctly described and the densimetric Froude similarity critérium is presented. The numerical modelling of this kind of avalanches (based on Navier-Stokes equations and on a turbulence model) is shown . The comparison between the two models is made in the case of aturbidity current. The numerical modelling allows to find global characteristics of the flow (such height and velocity of the avalanche front) and allows especially to access to the internal variables (pressure, concentration, velocity and turbulence characteristics)
Simulación de patrones de fracturación en rocas, distribución y características de su geometría fractal. Conectividad y Percolación
(Sociedad Geológica de España, 1996) Gumiel Martínez, Pablo; Hernández, R.
The results of more than 1000 simulations carried out using the SIMFRAC Programme, on fracture generation in rocks is presented in this paper. A numerical simulation method has been used to predict connectivity of fractured rock masses. In all simulations performed there is a threshold of fracture density, below which fractures are poorly connected with no percolation. Where fracture density is at the Percolation Threshold, a continuous and connected Fracture Cluster is developed starting the percolation of the system. The geometrical configuration of the Critical Fracture Cluster is determined by his fractal dimension, which consequently may be used to measure the connectivity of fractured rock masses
Resultados preliminares de la aplicación de lodos de depuradoras como fertilizante y su implicación en la migración de nitratos a través de de la zona no saturada
(Sociedad Geológica de España, 1996) Reyes, J.; Martínez Pérez, Silvia; Sastre Merlín, Antonio; Bigeriego, M.; Porcel, M. A.
The results of field experiments over use of the composted sewage sludge compared with mineral fertilizer in corn crops are presented. Also, the nitrate leaching through the unsaturated zone and its arrival to groundwater is studied. The amount of nitrate adds from the composted sewage sludge is, lesser than the traditionally fertilizers. This can substitute the traditionally fertilizers, because reduced the possibility of contamination and equaled the yield
Puntos de interés geológico en un espacio periurbano (Badalona). Una herramienta para la enseñanza de la geología
(Sociedad Geológica de España, 1996) Andreu, A.; Carceller, F.; Parés, J. M.
In order to improve the geological maps o f the Badalona area o f Barcelona, a geological scheme o f the area was generated by the GIS program which was used to digitize information from orthomaps. Ground truth was provided by field work carried out at a series of the most important geological locations of the area. Information collection was carried out by secondary school students supervised by Earth Sciences teachers. The use of geographical information systems (GIS) combined with field data provides an important new tool for use In the improvement of geological and scientific knowledge.
Programas-Guía de actividades para desarrollar el principio de localización espacial en Ciencias de la Tierra en la enseñanza Primaria y Secundaria
(Sociedad Geológica de España, 1996) Lillo Bevia, J.
The spatial location principle Is common to many Sciences of the Earth and of the Life, and to develop the abilities implicate in the dominance of the perception of the space in the natural physical means, a series of programs - activities guide are presented in progressive form for non universitary educational levels. The designed activities permit to develop abilities that they should possess the citizens as a rule, and are considered previous to approach some of the Sciences of the Earth or of the Life (Geology, Environmental Geology, Physical Geography, Ecology, ....) systematically in high level studies
Precipitaciones máximas en el Campo de Dalias y vertiente meridional de la Sierra de Gádor (Almería)
(Sociedad Geológica de España, 1996) Martín Rosales, Wenceslao; Pulido Bosch, Antonio; Vallejos, Ángela; López Chicano, Manuel
A comparative analysis was carried out between two classical statistical models of rainfall: the extreme annual value series model, applying the Gumbel distribution, and the partial duration series method. Both were applied to Campo de Dallas and the southern edge of the Sierra de Gador, a semiarid Mediterranean area. Though the partial duration series is clearly superior when measuring oyer a short period of time, the Gumbel distribution for extreme annual values has the advantage of simplicity . and speed of application for longer duration series.
Panorama de la investigación geológica en España a través de sus Congresos nacionales (1984-88-92)
(Sociedad Geológica de España, 1996) Gutiérrez, M.; Alcalá, Berta; Escorza, C. M.
We show a study of the geological research carried out in Spain in the last 12 years. The papers published in the three National Geological Congresses celebrated in Spain until now are analyzed and the following matters are considered: object of study, geological area, and institution in wich the author works. The results are shown in several graphics. The analysis of the Congresses show the tendency and changes of the main geological research lines in Spain
Modelos termodinámicos y de balance y transferencia de masas entre las aguas subterráneas y las rocas graníticas del Sistema Central (Cuenca del Alberche)
(Sociedad Geológica de España, 1996) Martín Loeches, Miguel; Sastre Merlín, Antonio; Almeida, C.; Vicente Lapuente, R.
The main porpuse of this work is to describe the relationship between the grounwater and the mineral composition of the granitic rocks in the meridional region of the Alberche river basin. We construct several geochemical reaction model in order to explain the different composition of the groundwaters
Modelización del comportamiento dinámico de los suelos granulares densos. Movilidad cíclica
(Sociedad Geológica de España, 1996) Mateos Garcia, M. T.; Estaire, J.
This paper shows the results of the mathematical simulation of the dynamic behaviour of a dense granular soil when tested in a triaxial device. Under these conditions and due to the capability of these soils to increment their volume a process, known as cyclic mobility, is developed. Although this process does not imply a total lose of the soil strengh, it is possible that the soil develops important strains. The used model is an elastopiastic one based on the Generalized Theory of Plasticity. This model was adapted in order to be able to reproduce the dynamic behavio ur of dense granular soils
Modeling fluid flow and heat transport in compressive sedimentary basins: application to the Ainsa basin
(Sociedad Geológica de España, 1996) Bitzer, K.; Travé i Herrero, Anna; Calvet, F.; Labaume, Pierre
We present a method of modeling the hydraulic and thermal evolution of sedimentary basins that undergo compressive deformation. A finite-element mesh generatoris used , that is capable of creating bandwidth optimized meshs taking into account geometrical deformations caused by sediment consolidation, lateral movements of thrust sheets and erosion al events. A finite-elements modelis used to solve the equations of fluid flow, sediment consolidation as well as solute- and heat transport. We apply the model of the Southern Pyrenean foreland basin of Ainsa in order to constrain fluid flow evolution during the emplacement of thrust sheets. Furthermore, we compare the data obtained by petrological and geochemical studies in the Ainsa bain host rocks and veins to corroborate the application of this method
Microfábrica de las arcillas azules del Guadalquivir y su relación con los procesos de meteorización
(Sociedad Geológica de España, 1996) Tsige, Meaza; González de Vallejo, L.
Guadalquivir blue clays are strongly afected by physical weathering which Is responsible of considerable geotechnical problems in engineering works associated with landslides. Microfabric and mineralogy properties have been studied using the XRD and SEM, to asses possible changes in their internal properties with the weathering process. Different weathering profiles of this clays have been described using field criteria, on which mineralogical composition and microfabric aspects were assesed. The results have indicated that, the geotechnical problems are not caused by a change in mineralogical and chemical aspects, but rather a combination of slaking, brittleness and disaggregation, resulting from stress release. It has been shown also that these processes are stimulated by the presence of expansive type clay minerals in the sediment. However the interlaminar cation is Ca, where by the osmotic expansion is not determinative but rather the interlaminar one developed mostly between the aggregates.The most important element affected by this process Is the microfabric feature represented by discontinuios day matrix microfabric type, and existance of floculated aggregates in FE arrangement of clay plates. These arrengements favours fragmentation of the sediment into small aggregates with dessication and humectation cycle accelerated with the clay nature.
Microcontaminantes orgánicos en las aguas subterráneas de la Comunidad de Madrid en relación con las distintas unidades geológicas
(Sociedad Geológica de España, 1996) Gómez Artola, C.; Bustamante, I. de; Gómez Pérez, M. T.
As a part of a study on "Organic micropollulants in Madrid groundwater", a global characterization and evaluation of the detected pollulants are presented. From the analytical data and attending to the hydrogeological units where water samples are placed, we can assess that the highest global organic pollulants values are found in the Upper detritical tertiary hydrogeological unit; meanwhile, the lowest contents ocurr in the Paleozoic hydrogeological unit. An assessment of the overall detected organic compounds show the greatest quantities for phenols, carboxilic acids and esters
MF96:Un programa interactivo para determinación gráfica de mecanismos focales
(Sociedad Geológica de España, 1996) Cabañas, L.; Lindo, R.; Herráiz, M.
This communication describes the characteristics of a computer program based on the analyses of polarities of first P-wave motions and aimed at determining fault-plane solutions . The program allow us to estimate nodal planes and stress axes in a graphical and interactive way. The results are expressed in both, seismological and geological notation

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