Base level rise and per ascensum model of speleogenesis (PAMS); interpretation of deep phreatic karsts, vauclusian springs and chimney-shafts

In Mediterranean karsts, the Messinian salinity crisis induced first a deepening of the karst systems, then a flooding after the Pliocene transgression, and finally a reorganization of the drains after this base level rise. This reorganization mainly corresponds to the development of phreatic lifts: the chimney-shafts and the vauclusian springs. Such a per ascensum speleogenesis appears with a base level rise, which is caused by eustatism, by fluvial aggradation or valley infilling, or by continental subsidence. Consequently, we explain the origin of most of the deep phreatic cave systems (which are not hypogenic) by a base level rise, which flooded the deep karst, producing phreatic lifts connected to vauclusian springs.