La flore autunienne du site de l’étang de Martenet (Blanzy–Montceau-les-Mines, Bourgogne, France) : description, étude taphonomique et implications paléoenvironnementales

This work presents the first analysis of the Martenet fossiliferous site in the Blanzy – Montceau-les-Mines basin, as well as a proposition for transport and fossilisation conditions based on the sole collection material. Description of the megaflora revealed a classical ‘Autunian’ flora, out of which 90% is dominated by Walchian conifers. The taphonomical and sedimentological prospective based on the collection specimens allowed us to evaluate the transportation modalities of plant remains and to have an idea of the palaeoenvironment surrounding the Martenet fossiliferous site. Fragmentation is present on most plant remains, suggesting that a fair amount of transport has occurred prior to final deposition. This implies that the Martenet fossil site is the result of plant material accumulation sampled from a broad area. Comparisons done with previous palaeobotanical studies in other Permian basins show that even if all Permian plant assemblages are conifer dominated, the dominant species is not the same. This suggests that within a similar sedimentological context, paleoecological and/or palaeogeographical preferences can be observed within ‘Autunian’ conifers.