The granite and glacial landscapes of the Peneda-Gerês National Park

Granite and glacial landforms are presented as the main geomorphological landscape features of the Peneda-Gerês National Park. The park was established in 1971 and it is the only national park and most important protected area in Portugal. The aesthetic attractiveness is supported mainly by the distinct granite landscape of the Gerês and Peneda Mountains, where the post-orogenic Variscan Gerês gran- ite facies occurs. The rugged relief is poorly covered by vegetation, differentiating it from the surrounding moun- tainous areas and the most distinctive landforms are bornhardts, locally named as “medas”. Typical glacial landforms, such as U-shaped valleys, cirques and moraines, express the sheltered character of a low-altitude glaciation, which is of great significance in the context of the Pleistocene glaciation in Southern Europe.This work is co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Inter nacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145- FEDER-007690 and Portuguese national funds pro vided by Fundação para a Ciência e Tecnologi

Geological Repository Layout for Radioactive High-level Long-lived Waste in Argilite

In the framework of the 1991 French radioactive waste act, Andra has studied the feasibility of a geological repository in the argillite layer of the Bure site for high level long lived waste. This presentation is focussed on the underground facilities which constitute the specific component of this project. The preliminary underground layout which has been elaborated is based on four categories of data: - the waste characteristics and inventory, - the geological properties of the host argillite, - the long term performance objectives of the repository, - the specifications in term of operation and reversibility. The underground facilities consist of two types of works: the access works (shafts and drifts) and the disposal cells. The function of the access works is to permit the implementation of two concurrent activities: the nuclear operations (transfer and emplacement of the disposal packages into the disposal cells) and the construction of the next disposal cells. The design of the drifts network which matches up to this function Is also influenced by two other specifications: the minimisation of the drift dimensions in order to limit their influence on the integrity of the geological formation and the necessity of a safe ventilation in case of fire. The resulting layout is a network of 4 parallel drifts (2 of them being dedicated to the operation, the other two being dedicated to the construction activities). The average diameter of these access drifts is 7 meters. The link between the surface and the underground is ensured by 4 shafts. The most important function of the disposal cells is to contribute to the long term performance of the repository. In this regard, the thermal and geotechnical considerations play an important role. The B wastes (intermediate level wastes) are not (or not very) exothermic. Consequently, the design of their disposal cells result mainly from geotechnical considerations. The disposal packages (made of concrete) are piled up in big cavities the diameter of which is about 10 meters and the length of which is about 250 meters. On the other hand, the design of the C waste disposal cells (vitrified waste) is mainly derived from their thermal power (about 500 W after a 60 year period of interim storage). The disposal cell is a tunnel the diameter of which is about 0,70 m and the length of which is about 40 m. The number of the disposal packages (made of steel) per cell, the spacing between two adjacent canisters within a given cell and the spacing between two adjacent cells are adjusted to limit the peak of temperature in the host formation at 100°C. The disposal cells are also characterized by favourable design factors which would facilitate the potential retrieval of the wastes. The whole underground layout would represent a surface area of several km2

SAHARAN DUST ON FUERTEVENTURA ISLAND (CANARIES): CHEMICAL AND MINERALOGICAL CHARACTERISTICS, AIR MASS TRAJECTORIES, AND PROBABLE SOURCES

International audienceFrom April 12 to 19, 1984, dust was [Windom, 1975; Chester et al., 1979; Sarnthein et collected by cascade impactor on Fuerteventura al., 1982] and, probably, to the mineral feeding Island, 100 km from the Saharan coast. The sam-of marine plankton. The dust outbreaks from ples were analyzed by X ray fluorescence spectro-northwestern Africa to the middle Atlantic and metry (elemental composition), by X ray diffrac-Western Europe have been much less studied. The tion (mineral constituents), and by scanning only samplings were carried out during oceanic electron microscope (SEM) and energy dispersive X cruises [Chester and Johnson, 1971; Parkin et ray analyzer (EDXA) examination (shape, surface al., 1972] and the results were compared to the features, and mineralogy of particles), with the marine sedimentation [Tetzlaff and Wolter, 198