Evidence for wildfires during deposition of the late Miocene diatomites of the Konservat- Lagerstätte Lake Saint-Bauzile (Ardèche, France) – preliminary results

Abstract

The freshwater diatomite deposits from Saint-Bauzile in the Ardèche (France) represent a first-class Fossil-Lagerstätte of late Miocene, i.e., Tortonian age. A large variety of different animals (i.e., insects, fishes, and mammals) and macro-plants as well as palynomorphs and lacustrine diatoms are known from this locality, in generally excellent preservation. This contribution presents preliminary results on charred plant remains, i.e., charred fern and grass remains, as well as partly charred wood of taxodioid cupressacean affinity, as evidence for the occurrence of wildfire(s) during deposition of the lower part of the diatomite sequence. Previously published volcanological and sedimentological evidence for the interpretation of Lake Saint-Bauzile as a maar is reviewed, re-interpreted, and discussed in combination with new observations.