THE EASTERN BOUNDARY OF THE GIANT KARST OF VAUCLUSE IN RELATION TO THE LINEAMENT-FAULT OF AIX-EN-PROVENCE (PROVENCE, ALPS, COTE-DAZUR REGION, FRANCE)

In the Saint-Donat area, along the Mardaric stream, a tributary of the mid Durance, water losses associated with temporary springs can be ob served. These springs run off overflows of the Vaucluse karstic system . Their impluvium extends over the limestones of the eastern part of t he Montagne de Lure; this karstic area contributes, with the runoff en tering into the losses, to the underground flows of the Fontaine de Va ucluse. As it rose eastwards, the drainage network of this giant karst was halted by the faults of the Aix-en-Provence lineament, in which v ery strongly deepening marls form a barrier around the aquifer. This i s new evidence of the part played by the Hercynian-inherited lineament framework in limiting giant karsts of the Vaucluse-type, as is the ca se for the Alpine carbonate platforms in which they have developed.