Fossil plant levels in fluvial to marine environments from the Dahar (Bathonian to Albian, southern Tunisia)

The late Jurassic/early Cretaceous formations of southeastern Tunisia (Tata ouine area), previously known for their richness in fossil wood, have recen tly given numerous levels with diversified plant imprints. These plant leve ls (wood and/or imprints) are generally located atop regional subaerial unc onformities. Above each of them, sand and conglomerate are deposited by cha nnelized fluvial system. Vegetation settled rapidly on these deposits and p alaeosoils were formed. The observation of numerous autochthony indexes con firms the rapid development of these soils, and their subsequent covering b y first transgressive sand levels. A classification of these plant levels i s proposed, in relation with their increasing autochthony index. Six types are defined. The distribution of these plant levels is related to sequentia l evolution of the deposits.