Contenu du sommaire

To the XIX century autochtonal rural society corresponded a highly organised space. Its destruction by huge housing schemes is but a trivial case of modern urbanisation. The case of the rural boroughs which grew around the industrial area of Saint-Etienne from the beginning of the XIX century seems more specific. They now duplicate the model of the town-ward and in most cases are annexed by the town or well on the way of being absorbed. A sociologic study of those devalorized spaces would improve the schemes of urban planning.

Called « puddled soils », the sandy clay which covers the right bank of the Loire in the Forez basin, have been spotted very early on in their development. At the end of the nineteenth century, a geologist named Le Verrier based a whole episode of the plain's morphonogical history on their being there. From then onwards, no investigator has taken it upon himself to define exactly what they one. After a detailed analysis of all the components, the « puddled soils » are not, it appears, deposits, it is fundamentally a question of a pedological horizon developped on two kinds of sediment : old alluviums and colluviums. They have formed gradually throughout the quaternary and cover up a stair-like system of terrasses along most of the right bank.

Eastern slopes of Monts du Forez, South West of Montbrison (Loire) show different levels from a summit level at 1,400 meters to plaine du Forez at 400 meters high only. Differing resistance of rocks to erosion is mainly responsible of landforms although some fault scarps are very probable. Landforms are also original because of inheritance from glacial time. From localization of their forms, it is possible to characterize three zones : — lower zone where linear erosion predominates ; — uper zone with thick arenisation and senile forms ; — intermediate zone where periglacial forms are preserved only in peculiar conditions.

For a very long time in the past, the river Gier had been flowing pure waters, which all along the XIXth century, had drawn up to its valley many different industries. But the pollution of this little river (which ends its course in the « Rhône ») is altogether an old phenomenon. Modern analysis are supporting the attentive observer's conclusions : the river is utterly polluted and does not deserve any more the name of « river ». Its natural physical and chemical qualities have disappeared because of the numerous effluents coming most from industries, and abnormally few from domestic uses. Efforts are nowadays made to struggle against pollution. Within a few years, three purification complexes will be built. Those could not however have full effects, if every class of the population is not conscious of the problem. The towns in the valley are a mixture of old fashioned factories and antique semi-ruined houses. They must be renewed with an absolutely different point-of-view : industries being confined in the valley itself, residential districts built on the neighbouring heigts. This would made easier the purication of waters from different origins. Thus are underlined the strings between intensive pollution, an efficient purification, and old fashioned land texture.