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

A dated phylogeny and collection records reveal repeated biome shifts in the African genus Coccinia (Cucurbitaceae)

Background: Conservatism in climatic tolerance may limit geographic range expansion and should enhance the effects of habitat fragmentation on population subdivision. Here we study the effects of historical climate change, and the associated habitat fragmentation, on diversification in the mostly sub-Saharan cucurbit genus Coccinia, which has 27 species in a broad range of biota from semi-arid habitats to mist forests. Species limits were inferred from morphology, and nuclear and plastid DNA sequence data, using multiple individuals for the widespread species. Climatic tolerances were assessed from the occurrences of 1189 geo-referenced collections and WorldClim variables. Results: Nuclear and plastid gene trees included 35 or 65 accessions, representing up to 25 species. The data revealed four species groups, one in southern Africa, one in Central and West African rain forest, one widespread but absent from Central and West African rain forest, and one that occurs from East Africa to southern Africa. A few individuals are differently placed in the plastid and nuclear (LFY) trees or contain two ITS sequence types, indicating hybridization. A molecular clock suggests that the diversification of Coccinia began about 6.9 Ma ago, with most of the extant species diversity dating to the Pliocene. Ancestral biome reconstruction reveals six switches between semi-arid habitats, woodland, and forest, and members of several species pairs differ significantly in their tolerance of different precipitation regimes. Conclusions: The most surprising findings of this study are the frequent biome shifts (in a relatively small clade) over just 6 - 7 million years and the limited diversification during and since the Pleistocene. Pleistocene climate oscillations may have been too rapid or too shallow for full reproductive barriers to develop among fragmented populations of Coccinia, which would explain the apparently still ongoing hybridization between certain species. Steeper ecological gradients in East Africa and South Africa appear to have resulted in more advanced allopatric speciation there

Les pointes de la Basse-Vallée du Tilemsi

Amblard-Rambert A., Gaussen J., Gaussen M. Les pointes de la Basse-Vallée du Tilemsi. In: Journal de la Société des Africanistes, 1960, tome 30, fascicule 2. pp. 123-143

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

Le tas de Beaufort au Plateau Parrain, (Commune de Saint- Front-de-Pradoux, Dordogne)

Le Tas de Beaufort est un amas de galets et de silex découvert sur le Plateau Parrain à quelque 40 mètres du fond de tente magdalénien fouillé en 1960. Les galets (grès, dolentes et surtout quartz) sont presque tous fracturés et rubéfiés. Le matériel en silex (Magdalénien moyen probable) est caractérisé par un outillage où prédominent les burins et où sont absents les esquilles et les menus déchets. Cette formation ne peut être ni une décharge domestique, ni un atelier de travail spécialisé, ni un dépôt d'objets culinaires. Il s'agit peut-être d'une cache à viande, cet ancêtre des congélateurs bien connu des peuples arctiques.Gaussen J., Sackett J. Le tas de Beaufort au Plateau Parrain, (Commune de Saint- Front-de-Pradoux, Dordogne). In: Paléo, n°2,1990. pp. 153-165