Présence d'ambre dans le Crétacé supérieur (Santonien) de La Mède à Martigues (Sud-Est de la France). Caractérisation IRTF

Nodules of fossil resin, associated with lignitized woods, have been found, next to the pond of Berre, not far from Martigues, in the area of La Mède in clayey and sandy laguno-brackish formations of Santonian age. A FTIR study, using attenuated total reflexion with a diamond crystal, as well as the comparison with ambers and a copal of reference and with the FTIR data of the literature, has shown that this resin has a lesser maturity than Cretaceous ambers rather comparable to Baltic ambers of the Tertiary. This low maturity is confirmed by the analysis of the associated lignitized woods. However, the chemical structure of the amber of La Mède appears very different from that of Baltic ambers.