Abstract:
Karsts of the alpine foreland north to the French Western Alps: glacial origin of the underground systems - Karstic mountains are described between Rhône valley and the border of Northern Alps. The influence of quaternary glaciers is evident for surface landforms and the existence of inactive canyons can be explained only by glacial outflows. Large underground caves and systems such as La Balme, Les Echelles, contain numerous blocks and pebbles of alpine rocks. Except in some places of the alpine mountains, the pre-quaternary karstic evolution cannot be investigated. Now the rate of karstic corrosion is too low and waters are unable to produce large caves. Only the mechanical action of whirling glacial flows in some pre-determinated places can explain the presence of large caves in these low karstic mountains. The formation of these kind of caves can be correlated with the existence of the actual canyons and “defilés” along this part of the Rhône river.