Adnan Kermandji, works in department of Biology, as a faculty of Nature and Life, University of Frere Mentouri, Constantine, Algeria.
The classic exposed Devonian sedimentary sequences of Oued Saoura west Sahara Algeria and Devonian succession of Steh borehole of eastern Sahara Algeria Syncline are studied. The investigated data show that most palynomorphs occur in grey to dark grey clayey siltstone and very fine argillaceous sandstone layers. Fossils of exposure rock samples are mainly mature to highly mature and poorly preserved. While those of Steh borehole samples are moderately to well preserved. The assemblages contain associations of miospores, tetrads, plant remains (cuticles, tissues and tubular structures) and few acritarch individuals. The studied miospore assemblages are identified and keyed into previously described palynostratigraphic miospore assemblage biozones of deep wells from the Tidikelt Plateau, central Saharan, Algerian and Oued Saoura out croups Hassan Kermandji et al.(2008, 2009, 2016) and those of the Old Red Sandstone Continent and adjacent regions by Richardson and McGregor (1986) and those from marine Devonian of the Ardenne-Rhenish regions by Streel et al. (1987).
The biostratigraphical data illustrate that the basal strata of Teferguenite Formation exposed in the Mongar Debad Km 30 section confirm faunal ages that are established on limited rock interval, are of Eifelian age. Subsequently the occurrence of characteristic miospore taxa in the higher studied sequence above the basal strata of the same formation indicate Givetian age.
The miospore assemblages contain diagnostic elements of Middle Devonian Algerian succession and those are common with contemporaneous miospore assemblages from Libya, Tunis, Saudi Arabia implying reasonably impressive correlation between northern Gondwanan regions and to some extent to those of Northern Hemisphere. The occurrence of distinguished miospore taxa, permit determining the boundary between Eifelian and Givetian strata.
Keywords: Devonian, miospore, palynostratigraphy, east-west sahara synclines, Algeria