Geochemical exploration in the Montseny Mountains (NE Spain)

A five year program of systematic multi-element geochemical exploration of the Catalonian Coastal Ranges has been initiated by the Geological Survey of Autonomic Government of Catalonia (Generalitat de Catalunya) and the Department of Geological and Geophysical Exploration (University of Barcelona). This paper reports the first stage results of this regional survey, covering an area of 530 km2 in the Montseny Mountains, NE of Barcelona (Spain). Stream sediments for metals and stream waters for fluoride were chosen because of the regional characteristics. Four target areas for future tactic survey were recognized after the prospect. The most important is a 40 km* zone in the Canoves-Vilamajor area, with high base metal values accompanied by Cd, Ni, Co, As and Sb anomalies. Keywords: Catalanides. Geochemical exploration. Stream sediments. Base metal anomalies. Principal Component Analysis.

Prospección geoquímica de flúor en las aguas superficiales del macizo Montseny (Barcelona y Girona)

En el Macizo Montseny-Guilleries se conocen antiguas explotaciones de fluorita y fluorita-baritina (Osor, Tagamanent, Espinelves, Sant Marcal, etc). Es por el1o que se ha utilizado el método de prospección geoquímica de flúor en aguas superficiales para detectar posibles zonas de interés hasta ahora desconocidas.

La cartografia de la flora del Montseny en reticle UTM d'1 km. de costat: plantejament i primers resultats

El present treball és un primer escrit sobre la cartografia corològica de les plantes vasculars en el massis del Montseny (Serralada Pre-litoral), en el qual exposem el plantejament del projecte i oferim uns primers résultats. Hi incloem també un mapa per espècie prenent com a unitat espacial el quadrat d'1 km de costat del reticle UTM. La presència de 1'espècie a cada quadrat és indicada en très graus d'abundància: espècie présent o rara, espècie fréquent i espècie abundant. L'àrea estudiada comprèn 513 quadrats d'1 km de costat, que pertanyen a 12 quadrats de 10 km de costat de la zona 31T del reticle UTM: DG 33, DG 43, DG 53, DG 63, DG 32, DG k2, DG 52, DG 62, DG 3 1 , DG kl, DG 51 i DG 6 l . Com a primera aportaciô presentem 10 mapes amb la distribució de Quercus ilex, Fagus sylvatica, Abies alba, Taxus baccata, Betula pendula, Cistus laurifolius, Cardamine heptaphylla, Ramonda myconii i Equisetum hyemale.

A detailed stream sediment Geochemical survey in the Canoves St. Pere de Vilamajor area (Montseny massif. NE Spain)

Se ha realizado una prospección geoquímica táctica de sedimentos aluviales en el Brea de Cánoves-St. Pere de Vilamajor (Macizo del Montseny, Barcelona), como consecuencia de una exploración geoquimica estratégica de sedimentos aluviales previa, en la que se localizó un Brea anómala en Pb, Zn, Cu, As, Cd, Ni, y Co. El Brea estudiada tiene 35 km2 y esta constituida por materiales sedimentarios y volcánicos del Paleozoico, metamorfizados en mayor o menor grado e intruidos por el granito de Vallfornés, y materiales detríticos terciarios...

L'home, la muntanya i el museu

Crònica de la Jornada titulada 'L'home i la muntanya' organitzada el 30 de novembre de 1992 pel Museu Etnològic del Montseny per parlar de la interrelació entre home i natura, tot prenent com a marc referencial la muntanya del Montseny

Omphalina Umbellifera (L. ex. Fr.)Quel. Novedad para la flora liquénica

Se da cuenta de la recolección en el Montseny, el Corredor y el Moixeró de varios basidiocarpos de Omphalina umbellifera(L. ex Fr. ) Quel. (= O. ericetorum (Pers.) M. Lange), en taludes y sobre madera en descomposición.

Rockfall induced seismic signals: case study in Montserrat, Catalonia

After a rockfall event, a usual post event survey includes qualitative volume estimation, trajectory mapping and determination of departing zones. However, quantitative measurements are not usually made. Additional relevant quantitative information could be useful in determining the spatial occurrence of rockfall events and help us in quantifying their size. Seismic measurements could be suitable for detection purposes since they are non invasive methods and are relatively inexpensive. Moreover, seismic techniques could provide important information on rockfall size and location of impacts. On 14 February 2007 the Avalanche Group of the University of Barcelona obtained the seismic data generated by an artificially triggered rockfall event at the Montserrat massif (near Barcelona, Spain) carried out in order to purge a slope. Two 3 component seismic stations were deployed in the area about 200 m from the explosion point that triggered the rockfall. Seismic signals and video images were simultaneously obtained. The initial volume of the rockfall was estimated to be 75 m3 by laser scanner data analysis. After the explosion, dozens of boulders ranging from 10¿4 to 5 m3 in volume impacted on the ground at different locations. The blocks fell down onto a terrace, 120 m below the release zone. The impact generated a small continuous mass movement composed of a mixture of rocks, sand and dust that ran down the slope and impacted on the road 60 m below. Time, time-frequency evolution and particle motion analysis of the seismic records and seismic energy estimation were performed. The results are as follows: 1 ¿ A rockfall event generates seismic signals with specific characteristics in the time domain; 2 ¿ the seismic signals generated by the mass movement show a time-frequency evolution different from that of other seismogenic sources (e.g. earthquakes, explosions or a single rock impact). This feature could be used for detection purposes; 3 ¿ particle motion plot analysis shows that the procedure to locate the rock impact using two stations is feasible; 4 ¿ The feasibility and validity of seismic methods for the detection of rockfall events, their localization and size determination are comfirmed.

Corologia de la flora vascular d'interès de conservació al Parc Natural del Montseny

Presentem els resultats dels estudis realitzats des del 2009 al 2012, amb la finalitat de millorar la informació corològica disponibled'espècies de flora vascular considerades d'interès de conservació al Parc Natural del Montseny. S'han tingut en compte un total de 125tàxons. D'aquests, 3 corresponen a tàxons nous per la flora del massís (Aconitum vulparia, Botrychium matricariifolium i Polystichumlonchitis), 7 han estat retrobats i 13 corresponen a novetats per algun dels quadrats UTM 10 × 10 prospectats. Tot i les troballes, moltesespècies no han sigut localitzades durant el treball de camp. En alguns casos, atribuïm aquest fet a la reducció de les poblacions o fins i tota la desaparició, fet que afecta principalment a aquelles espècies vinculades majoritàriament a ambients oberts, que han patit una recessióimportant durant les darreres dècades. Aquest fenomen ha estat especialment rellevant al massís del turó de l'Home, sobretot a la vall deSanta Fe

Anàlisi geomètrica del Diaclasat de les Guilleries en el sector de la Vall del Ter entre els embassaments del Pasteral i Susqueda (Girona)

The Guilleries are a small and mountainous area located in the north-westem part of the Catalonian Coastal Ranges where metamorphic and igneous Paleozoic rocks are exposed. After the main hercynian folding this area was affected by a brittle deformation that is mainly manifested by the intrusion of a very large number of dykes of granodiorite and the development of a complex joint system. Trends of dykes indicate that their intrusion was related to a SE-NW extension, whose estimated value is 40% on an average. This extension seems to stand, although without any associated igneous event, with the development of NE-SW directed joints which make the main set. Five families more were developed later, onegently-dipping and fou upright; the latter trending roughly SE-NW, ENE-WSW, ESE-WNW and N-S. AU the joint sets appear in the metasedimentary Paleozoic rocks and in the hercynian intrusive bodies. Concerning the ages, joints that belong to the NE-SW and SE-NW directed sets and also those slightly dipping have been attributed to the late-hercynian times and all the other are considered to be later

La geotecnia vertical aplicada a la rehabilitación de yacimientos pleistocenos

La aplicación de una serie de técnicas propias de la geotecnia vertical y de la consolidación de taludes y laderas inestables se presenta por primera vez aplicada a la rehabilitación de yacimientos pleistocenos ubicados en antiguas canteras. Un conjunto de actuaciones especializadas permite garantizar la seguridad en los trabajos así como la preservación de la integridad de los yacimientos ubicados en cortes verticales y laderas rocosas. La rehabilitación realizada en el yacimiento de la Cova del Rinoceront (macizo del Garraf, NE de España), ubicado en el frente de explotación de una antigua cantera de piedra caliza, es el primer ejemplo conocido en la Península Ibérica donde la geotecnia vertical hasido utilizada en este tipo de contextos y, por lo tanto, los resultados pueden ser utilizados como un posible modelo de futuro para próximas intervenciones.

Modeling storm events to investigate the influence of the stream¿catchment interface zone on stream biogeochemistry

We formulate a new mixing model to explore hydrological and chemical conditions under which the interface between the stream and catchment interface (SCI) influences the release of reactive solutes into stream water during storms. Physically, the SCI corresponds to the hyporheic/riparian sediments. In the new model this interface is coupled through a bidirectional water exchange to the conventional two components mixing model. Simulations show that the influence of the SCI on stream solute dynamics during storms is detectable when the runoff event is dominated by the infiltrated groundwater component that flows through the SCI before entering the stream and when the flux of solutes released from SCI sediments is similar to, or higher than, the solute flux carried by the groundwater. Dissolved organic carbon (DOC) and nitrate data from two small Mediterranean streams obtained during storms are compared to results from simulations using the new model to discern the circumstances under which the SCI is likely to control the dynamics of reactive solutes in streams. The simulations and the comparisons with empirical data suggest that the new mixing model may be especially appropriate for streams in which the periodic, or persistent, abrupt changes in the level of riparian groundwater exert hydrologic control on flux of biologically reactive fluxes between the riparian/hyporheic compartment and the stream water.