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Expresión geomorfológica de la actividad reciente de la falla de Amer (NE de la Península Ibérica)

  • FERRER, P.
  • MASANA, E.
Triangular facets, related drainage basins, alluvial fans and subtle scarps reveal the recent activity of the normal Amer fault (NE Spain). The 1427 earthquakes which reached epicentral intensities ranging between VI1 and VI11 have been attributed to the Amer fault. However, the geomorphologic and geologic characteristics of this fault (30 km length) suggest that it might be capable of producing larger earthquakes than those occurred during de 15th century.

Late Miocene alluvial sediments from the Teruel area: Magnetostratigraphy, magnetic susceptibility, and facies organization

  • Garcés Crespo, Miquel
  • VAN DAM, J.
  • CALVO, J.P.
  • ALCALÁ, Luís
We present the paleomagnetic dating of the upper Miocene red alluvial to palustrine sequences of the area north of Teruel. The magnetostratigraphy of the Masada del Valle and Masada Ruea sections indicates a minimum age of about 11 Ma to the lowermost sediments post-dating the unconformity over the Mesozoic basement. The overall Miocene sequence represents a retrogradation of the alluvial system, grading upwards into palustrinellacustrine sedimentation. The onset of palustrine deposition is dated in Masada Ruea at about 9.7 Ma. The late Vallesian faunas of Masía del Barbo, of which leve1 2B is the reference locality of biochronozone MN10, are dated to 9.3 Ma. The anisotropy of magnetic susceptibility (AMS) in the tenigenous sediments suggests that the orientation of the magnetic ellipsoids represents the paleocurrent direction. Paleocurrent interpretations based on AMS data can be used for a better comprehensionof the facies arrangement in the Neogene sediments of the Teruel basin.

Macrocystella? durandi sp. nov. (Echinodermata, Rhombifera) y el registro del género Macrocystella en la cuenca cambro-ordovícica del norte argentino

The new species Macrocystella? durandi n. sp. is characterized for the Tremadoc of Northern Argentina, and six new localities bearing the genus Macrocystella CALLAWAY within the A rgentine Cordillera Oriental are introduced. The fossiliferous material comes from shale and sandstone levels of the Casa Colorada, Alfarcito, Rupasca and Saladillo Formations (Santa Victoria Group), that crop out in different localities of the Quebrada de Humahuaca (Jujuy Province), and the Angosto de la Quesera (Salta Province). The biostratigraphic framework of the fossils is also given, showing the oldest record of Macrocystella CALLAWAY in the Upper Cambrian of the Casa Colorada Fo rmation at the locality of Pintayoc, north of Humahuaca town (Jujuy Province). A discussion on the taxonomy of the genus is given, analysing the information published until now within the Argentine-Bolivian cambro-ordovician basin. Macrocystella? durandi n. sp. differs from the rest of the species of Macrocystella? by its delicate ornamentation on the thecal plates, with fine and numerous folds, as well as by the possible pectinirrombs developed on some fields between the main (axial and radial) folds.

Nouveaux Orthoptères (Ensifera, Insecta) du Trias des Vosges (France)

  • NEL, A.
Three new Orthoptera, Ensifera (Hagloidea and Gryllavoidea) from the Grés à Voltzia (Upper Buntsandstein, transition Lower / Middle Triassic) of the Vosges (France) are described based on forewings. Galliagryllavus vogesiacus n.gen., n.sp. (Gryllavidae) shows affinities with Gryllavus madygenicus SHAROV 1968 from the Triassic of Madygen (Kirghizistan). Triassoparacyrtophyllites bifurcatus n.gen., n.sp. (Tuphellidae) displays some similarities with Paracyrtophillites undulatus SHAROV 1968 from the Upper Jurassic of Karatau (Kazakhstan). Voltziahagla pseudoveinosa n.gen., n.sp. (Haglidae) seems close to the genus Archaboilus MARTYNOV 1937 from the Lower Jurassic of Shurab (Tadjikistan). These three Ensifera which belong to distinct families underscore the diversity of the Hagloidea and the Gryllavoidea at the boundary between the Lower and Middle Triassic. A cladistic study would be necessary to determine the phylogenetical relationships between the different families .

Bioerosion and bioturbation of a weathered metavolcanic rock (Cretaceous, Czech Republic)

The locality of Hill (N Bohemia, Czech Republic) yielded an example of a Cretaceous sea-bottom composed of Nametarhyolite. Two types of trace fossils penetrate the substrate, namely Thalassinoides isp. and Gastrochaenolites isp. Thalassinoides originated presumably in a firmground, i.e. the metavolcanite had to be "delithified" in some patches and subsequently re-hardened again. ?Gastrochaenolites isp. is interpreted as a boring trace of decapods.

El Lluís Solé i Sabarís i l'escola catalana de Geologia

  • VIRGILI, Carmina
L'objectivitat i la imparcialitat són, sens dubte, dues qualitats indispensables per a l'historiador que vol analitzar científicament un fet del passat jo diria, en canvi, que no són indispensables, ni tan sols desitjables quan intentem d'aproximar-nos a la realitat d'una persona arnb qui hem conviscut.Per això, aquestes ratlles sobre aquell a qui jo considero una de les figures més importants de la geologia del nostre país a partir dels anys quaranta, seran conscientment i voluntàriament subjetives i parcials. (...)

Estudio de los Muricidae del Plioceno del Empordà (Catalunya, España). Descriptiva y sistemática

  • MARTINELL, Jordi
In the present paper seven species of Muricidae (Neogastropoda, Gastropoda) from the Pliocene of Empordà, (Catalonya, Spain) are described. Both new material and material coming from already existing collections have been studied. Where there are a sufficient number of individuals, the descriptions is acompanied with the following numerial information: maximum (M), minimun (m), the mean (x), standar desviation (s), variance (s2), mean and variance intervals, and the correlation coefficient (r).

Interrupcions sedimentàries i paleoalteracions

  • VIRGILI, Carmina
El registro de los tiempos geológicos en la sucesión estratigráfica es muy incompleto ya que los períodos de no deposición son más importantes que los de sedimentación. Durante estas interrupciones, estas discontinuidades, se producen alteraciones que modifican profundamente los caracteres sinsedimentarios. Son debidas a procesos pedogenéticos pero también a la acción de las aguas subterráneas. El resultado de las mismas produce una "continentalización" de las series, lo que ha llevado a errores en la interpretación de ciertas facies. El estudio de estas paleoalteraciones permite obtener conclusiones paleogeográficas y paleoclimáticas.

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