[en] Deep argillaceous formations have physical properties likely to favour the long-term radioactive waste disposal (very low intrinsic permeability, radioactive element retention). But, these properties may be changed by the existence of discontinuities in the host medium. It's why, the characterization of the processes of fluid migrations associated with the fracturing was necessary within the experimental research program, launched by the Institute for Nuclear Safety and Protection (IPSN), which study a thick Toarcian formation composed of clay-stones (argilites) located on the Tournemire area (Aveyron, France). In the first step, the micro-tectonic and kinematic analysis provided the chronology of deformation with the main steps of the setting and the evolution of the tectonic fractures network. The microstructural analysis of the filling fractures showed fractures was alternatively, during the tectonic events, tight, permeable or semi-permeable (or semi-tight). These 'hydraulic states' were controlled by the nature and architecture of the structures of deformation and by the petro-physics properties variations of the argilites in the core zone and damage zone of the fractures. Mechanisms involved in the permeability variations in the fractures were argued and some parameters, as the magnitudes of differential stress, were estimated by the dynamic analysis of the twinning of calcite crystals contained in the core zone of fractures. Besides, the twinning analysis provided several data about the contexts of deformation and the development of the fractures network in the argilites. (author)

[en] Published in summary form only

No abstract available

No abstract available

No abstract available

[en] Published in summary form only

No abstract available

No abstract available

No abstract available

[en] In this study the dry input of atmospheric particles into forest stands is quantified. The chosen method, a washoff- method using the natural leaf surfaces as collectors of the dry deposition, was standardized on spruce (Picea abies (L.) Karst.) and experimentally applied to other tree species, forest stands, and climatic regions. The field measurements were achieved predominantly in a spruce stand at Solling (Germany) and in a pine and eucalyptus stand at Herdade da Espirra (Portugal). To judge the trend of air pollution unaffected by normal meteorological deviations, continuing measurements were taken for several years at the main research site at Solling. At this site, the concentration developments of NO₃^-, NH₄⁺, and SO₄^2- show an average annual pattern that varies in distinction according to the components. A comparison between the research sites in Germany and Portugal shows that the ion-balance of the aerosol at Solling is strongly dominated in the fine fraction by ammonium and sulphate, while at Herdade da Espirra the composition of ions is dominated by sea salt particles. Dry particle deposition constitutes an important part of the total matter input into forest ecosystems. Just the nitrogen input into Solling only by dry deposition (from particle, mist, and gas deposition) with about 30 kg N ha^-1 a^-1 already exceeds the critical load of 20 kg N ha^-1 a^-1 by far. Only a quick and drastic reduction of sulphur and nitrogen emissions could stop the further increase of the nutrient imbalance and the progressing acidification of this ecosystem. (author)