RELATIONS BETWEEN CARBONATE DISSOLUTION A ND TERRIGENOUS FILLINGS IN THE CHALK KARST OF NORMANDY

In Normandy, chalk karstic caves generally present silty clay loam fil lings. Silicious lamina or flint nodule horizons are interspersed in c halk layers; sometimes they have a chronological significance in the s ubterraneous network evolution. They often show that terrigenous filli ngs accumulate as the drain is hollowed out, per ascensum. The drain's functional section is always much smaller than gallery dissolved out in the chalk. Consequently, in particular contexts, karts drains are h ollowed out and functional only during one single period.