Sobre la presencia de una flora de Paleomanglar en el Paleogeno de la depresión central catalana (curso medio del Llobregat)

La presencia de fiuits compléts de Nipadites burtini s.a. juntament amb fiagrnents abundants corresponents a frondes d'Acrostichum lanzeanum, en molt bon estat de conservació, ens informen sobre la presencia de paieornanglars durant l'Eo&, a la Depressió Central Catalana. La natura i ecologia d'aquestes dues especies s'analitzen com a definidores del paieobiotop, així com les seves afinitats amb els mahglars actuals

Consideraciones sobre el nivel estratigráfico de la cuenca hullera de "La Camocha" en relación con el estudio de los Sphenteris

Se discute la posibilidad de que la mina de "La Camocha" (Asturias) sea del Westfaliense C, o B superior, por el estudio cle su Flora, especialmente de los Sphenopteris

Nota sobre el hallazgo de la forma fértil de Sphenopteris matheti ZEILLER

In this paper, the discovering of a small frond of Sphettopteris matheti Z. showing its characteristic aphlebia, is described. A portion of the specimen is not fertile, while another one presents Discopteris type sporangia on the pinnulas

Trabajos sobre la flora del Estefaniense cantabroastúrico

Con motivo del estudio de los Sphenopteris del Estefaniense cantabroastúrico, que ha constituido nuestra tesis doctoral, hemos revisado la flora fósil deeste nivel, resultando una serie de trabajos, algunos septietnde ellos publicados recientemente y otros todavía en estudio.Durante el pasado año 1964 en el número 9 del Boletín del Instituto de Estudios Asturianos se ha publicado bajo el título "Contribución al estudio de nuestra flora carbonífera de Tineo (Asturias)" una nota que había sido presentada en la I " Reunión Nacional de Geología celebrada en Oviedo en el año 1962. En ella se describen 19 especies de plantas fósiles reconocidas por nosotros en la cuenca carbonífera de Tineo

Trabajos realizados en el laboratorio de paleobotánica del Instituto de Investigaciones Geológicas "Lucas Mallada"

Como continuación de los trabajos emprendidos en las cuencas estefanienses del noroeste de España se ha publicado, en el volumen XX de la revista Estudios Geológicos, en colaboración con la Dra. J. Doubinger de la Universidad de Estrasburgo, la descripción de una nueva especie de Pseudomariopteris la Cuenca de Villablino, que cuenta con escasísimas descripciones de su flora fósil. El título de la publicación es Pseudomariopteris villablinensis n. sp. du Stéphanien de Villablino (León)". (...

Sphenopteris asturica nueva especie

Se describe un ejemplar (holotipo) de la Cuenca de Tineo (Asturias) que se atribuye a una nueva especie del género Sphenopteris caracterizada por sus raquis acanalados que portan pínulas de contorno triangular alargado de bordes lobulados, con nervio central neto y sinuoso decurrente sobre el raquis que emite nervios secundarios de forma pecopterideana. Presenta esta especie semejanzas con Sph. burgkensis Sterzel (= Sph. leptophylla Bunb.) y con Sph. goniopteroides Lesqu.Se figura también un ejemplar de Commentry (Francia) así como dos pequeños fragmentos de Puerto Ventana. Todos los ejemplares figurados así como otro citado procedente de Surroca (Gerona) proceden de niveles estefanienses

Contribution a la connaissance de la flore carbonifère des pyrénñees basques (Larroun et Ibantelly)

In this work we descrive fossil plants collected in Piri- neos mountains. Here are classified 33 species of which thirteen lias been stated in the coaldfield for first time. The coaldfield is dated as the upper Stephanian B or as the low Stepha- nian C

The severe thunderstorm of 4 October 2007 in Mallorca: an observational study

During the afternoon of 4 October 2007, a thunderstorm swept across the Island of Mallorca from southwest to northeast. Strong straight-line winds (up to 30 m/s) and heavy rain (rates up to 100 mm/h) were registered accompanying the storm. Tornadoes with an estimated intensity of F2–F3 developed nearby the city of Palma, severely affecting industrial installations. One person was killed by the impact of heavy debris while more than 10 million € in damages were attributed to the event in the industrial area only. The observed evolution of temperature, humidity, wind and pressure, as well as the sequence of radar images, reveal that a squall line was initially organized over the sea and then moved north-eastwards at an estimated speed of around 80 km/h. This paper presents an analysis of the event from an observational point of view. The aim of the study is to contribute to the characterization of these rare events in the Western Mediterranean by analyzing the observational information available for this particular extreme event. The diagnosis is aimed at helping forecasters to identify this kind of organized deep convective events and being able to issue timely warnings. The synoptic scenario shows warm and moist advection at low levels over Balearics and an upper-level trough over mainland Spain. This situation is known to be prone to deep convection in Mediterranean Spain in autumn. Radiosonde ascents from Murcia and Palma show convective instability at mid levels that can conduce to develop convection if appropriate ascents occur. A plausible lifting mechanism to trigger convection is attributed to large amplitude gravity waves, registered as short-period pressure oscillations by surface barographs

A deep cyclone of African origin over the Western Mediterranean: diagnosis and numerical simulation

International audienceFrom 19 to 22 December 1979, a deep cyclone evolved over the Western Mediterranean. Gusty winds of more than 30 m/s, as well as a strong pressure decrease to about 990 hPa were recorded in Palma de Mallorca (Balearic Islands, Spain). ECMWF analyses are used for a diagnosis and numerical study of the case. Sensitivity experiments using the HIRLAM model are performed to assess the role of the surface sensible heat flux, latent heat release and orography on the genesis and evolution of the cyclone. At synoptic scale, the situation is governed by the instability of an upper-level short wave. The cyclone developed within a notable baroclinic environment, which resulted from a cold advection from the northwest towards North Africa. The baroclinicity at first stages of the cyclogenesis is quantified by means of the Eady model. At latter stages, the evolution of the potential vorticity structures at high levels reveals a wide tropopause fold over the cyclone, as well as the presence of a strong anomaly associated with the low-level system. Sensitivity experiments reveal a notable cyclogenetic role of the latent heat release throughout the atmosphere in the deepening of the low, whereas no significant effect of the surface sensible heat flux is obtained for the simulation interval. On the other hand, an unusual cyclolytic role can be attributed to the northern ranges of the Mediterranean basin. Effectively, the low enlargement and deepening is constrained by a "wall effect", which is a consequence of the interaction of the cyclonic flow and those northern mountainous systems