Image analysis techniques are used to quantify finite strain in microconglomerates from the ‘Zone Houillère’ (Briançonnais Zone, French Alps) using the normalized Fry method. Two different techniques have been developed to extract the necessary parameters from quartz grains: the first uses an interactive videographic image analyser linked to a digitizer, and the second uses a semi-automatic image analyser algorithm working on numeric images. Comparison between these two techniques allows the data provided by the latter to be validated. Semi-automated image analysis is then employed to compute the characteristics of the finite strain ellipse as defined by the normalized Fry method. This has been tested on natural and simulated fabrics and gives accurate results. Finally, these techniques have been applied to samples from the French Alps, in an attempt to correlate the regional pattern of finite strain with deep seismic reflectors. This paper presents the preliminary results using finite strain data determined by image analysis processing.

Local glacial fluctuations and flood occurrences were investigated in the sediment sequence of proglacial Lake Muzelle. Based on geochemical analysis and organic matter content established using loss on ignition and reflectance spectroscopy, we identified six periods of increased glacial activity over the last 1700 yr. Each is in accordance with records from reference glaciers in the Alps. A total of 255 graded layers were identified and interpreted as flood deposits. Most of these occurred during glacial advances such as the Little Ice Age period and exhibit thicker deposits characterized by an increase in the fine grain-size fraction. Fine sediment produced by glacial activity is transported to the proglacial lake during heavy rainfall events. The excess of glacial flour during these periods seems to increase the watershed’s tendency to produce flood deposits in the lake sediment, suggesting a strong influence of the glacier on flood reconstruction records. Thus, both flood frequency and intensity, which is estimated based on layer thickness as a proxy, cannot be used in reconstruction of past extreme events because of their variability. There is a need to take into account changes in sediment supply in proglacial areas that could preclude satisfactory interpretation of floods in terms of past climate variability.

Living at high altitude carries risks, so settlement there can be thought marginal. Its success or failure ought to be dependent on the environment and the climate. But recent fieldwork in the French Alps shows that exploitation was not coincident with climatic conditions: Mesolithic people found the hunting good; in the climatic optimum of the Roman period the high altitudes were said to be uninhabitable and apparently were; while in the Little Ice Age of the fourteenth century and later, the high Alps were at their busiest. The author hypothesises that social control and perception, rather than climate, were the determinant factors.

Le catalogue des Chironomidés des Alpes françaises et des basses régions avoisinantes, c'est-à-dire de la portion du territoire français située au sud et à l'est du Rhône (Camargue comprise), est établi à partir des travaux antérieurs. L'aire couverte se présente comme une interpénétration complexe d'une partie de la zone 4 (Alpes au-dessus de 1 000 m d'altitude) et d'une partie de la zone 13 (basses régions occidentales au-dessous de 1 000 m d'altitude) de la Limnofauna Europaea d'Illies(1978).On a recensé au total 335 espèces, dont 13 nouvelles pour la zone 4 et 123 nouvelles pour la zone 13. En France, le total des espèces de Chironomidés connues des Pyrénées, du Massif Central, des Alpes et des basses régions situées approximativement au sud de la Loire et du Rhône s'élève actuellement à 496.