Contenu du sommaire

Summary. — This paper is an attempt to classify 176 « communes » of Grenoble area, using social classes, demography and local taxes as criteria. 19 variables have been first selected, then the matrix of initial data has been reduced by pricipal components factor analysis. Two ways of classification have been found. The first one, based on the scores obtained by the communes on two first axes includes nine categories. The second is a more accurate and satisfactory one as it takes under account the third axis and also relative importance of the three axes; it includes thirteen categories and so is sharper than the first one.

Abstract. — The freezing tests carried out on sandstone and ophiolites (pyroxenite, serpentinite, péridotite), samples from Northern Pinde (North-Western Greece), reveal that those rocks are not ot little subject to frost-weathering, but for serpentinite. This can be explained by their moderate porosity, and by the pétrographie characteristics, wich condition mechanical resistance. So, the pore-space and the mechanical resistance of a rock appear to be the two main factors, and the two measurable components of liability to frost-shattering.