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Abstract. Silty sands and clayey silts taken from a landslide in the Agri Valley have been analysed in order to study the role of sediment composition in the slope stability and the development of a slip zone. A geognostic hole was used to collect samples and monitor movements. A slip zone at a depth of about 14 m was identified. Compositional and physical-mechanical characterisation of samples was carried out. Some compositional characters, such as a 32-2 µm grain-size fraction, clay mineral content, cation exchange capacity and total nitrogen, increase in the slip zone. Some correlations have been found between geotechnical properties (residual shear strength and residual friction angle) and the same compositional characters, which can therefore be considered possible factors influencing slope stability.

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Abstract.A PM 1 geochemical and mineralogical study using Scanning Electron Microscopy (SEM) was performed on a pilot site in the Agri Valley which is close to the oil pre-treatment plant (C.O.V.A) of Europe's largest on-shore hydrocarbon reservoir. The study identified PM 1 geochemical and mineralogical characters in the period before, during and immediately after a burning torch flare event. The finer fraction (D Fe < 0.7 µm) consisted mainly of secondary particles and soot. In the coarser fraction (D Fe ≥ 0.7 µm), natural particles originating from crustal erosion and soot were abundant. Fine quartz particles and lower Al / Si ratios are markers for desert dust origin, proving that a Saharan dust episode which occurred during the observation period played a significant role in supplying geogenic aerosol components to the PM 1 . Largest amounts of ≥ 0.7 µm fraction particles observed on the day of flare event may be due to a greater supply of Saharan geogenic particles. Soot had been significantly increasing long before the flare event, suggesting that this increase is also related to other causes, although we cannot exclude a contribution from flaring. S-rich aerosol consisted mainly of mixed particles originating from deposition and heterogeneous nucleation of secondary sulfates on mineral dust. Only-S particles were identified in the ≥ 0.7 µm fraction following the flare event. These particles may be indicators of larger amounts of sulphur in the atmosphere.