Stratigraphie du Dévonien Inférieur du Plateau du Tidikelt d'In Salah (Sahara Central Algérie)

lithologic sequences of the tidikelt boreholes are dated by, moderately fairly preserved, well known miospores of controlled stratigraphic range and on occasional well preserved acritarchs. the successive miospore assemblages are correlated with contemporaneous gondwanan miospore biozones and with euro-american comparable miospore associations. this proves that these successions are of lochkovian, pragian and emsian ages. the correlation also confirms local hiatus at the lochkovian, pragian and emsian tops and at the pragian base. these erosional events are accused by: lack of sedimentary deposits at these levels; decreasing in the number of sedimentary cycles and reducing sediments thickness of the successive cycles towards these levels. these cyclic series are dominated by medium grained wackes and sandy clays. the lochkovian deposits are of fluvial-lake origin, pragian is lake environment and emsian is dominated by marine sources.