CHRONOLOGIE ET SPATIALISATION DE RETOMBEES DE CENDRES VOLCANIQUES TARDIGLACIAIRES DANS LES MASSIFS DES VOSGES ET DU JURA, ET LE PLATEAU SUISSE

摘要

Establishment of a precise chronicle of the lateglacial and holocene climatic variations requires the use of various dating methods Among them, tephrochronology allows high-resolution dating and synchronization of these events at a regional scale and sometimes at a continental scale Study of the record of the climatic variations occuring in western Europe since twenty thousands years leads to the discovery of tephras levels and "cryptotephras" in sediments cored in lakes from the Jura and Vosges mountains, and the Swiss plateau Some of these levels are invisible to the naked eye. Their detection was obtained using magnetic susceptibility measurement with a 5 mm step along the cores.