Role aquifere des alluvions tuffacees dans les vallees seches du Quercy

Abstract

Abstract Discusses the role of calcareous tufa deposits in the ground-water hydrology of dry valleys, citing two examples of the occurrence of calcareous tufa in alluvial deposits of dry valleys of the Quercy region, France. The tufa is considered the product of subterranean deposition from waters, which at one time had emerged as a spring and deposited tufa on the surface at the foot of the valley slope, but which later percolated along newly formed lower-level fissures.