Biostratigraphie des spores, acritarches et chitinozoaires du Devonien de la synclise Illizi-Rhadames (Algérie) [Devonian spores, acritarchs and chitinozoan of Illizi-Rhadames synclisis (Algeria)]

The aim of the present paper is to provide accurate age assignment based on spores, acritarchs, and chitinozoan. Eight palynological biozones are defined based on the investigation of Devonian core samples from four boreholes of the Illizi-Ghadames basin in southeastern Algerian Sahara. These biozones are compared with previous spores zonations proposed by Richardson & Mc Grégor (1986) and Streel et al. (1987), respectively for the Old Red Sandstone Continent and for Northwestern Europe. Two main stratigraphic hiatuses are documented: the first includes the late Emsian, the whole Eifelian, and early Givetian; the second concerns the Upper Frasnian and the Lower Famennian time interval.