Mid-Upper Triassic benthic foraminifers from the Central and Southern Tunisian Atlasic Range

In the Central and Southern Tunisian Atlasic Range, outcrops of the evapori te-dominating Mid ?- and Upper Triassic series are restricted to tectonic t hickening zones (NS and EW deep fault network), such as the Rheouis and Sbi ba domes, or at the base of alpine overthrusts (North-South Axis, "Dorsale Tunisienne"). Poor in fossils, the Triassic of Tunisia nevertheless contain s successive microfaunistic assemblages; they are Ladinian ?-Carnian and Rh aetian in age, and occur within the oolitic carbonate wedges (TST of the 3( d) order sequences) linked to the main sea level rises on this part of the South-Tethyan margin. The Ladinian ?-Carnian foraminiferal assemblage with Aulotortus praegaschei-Triadodiscus eomesozoicus characterizes two distinct levels (F3b and F4) cropping out in the Rheouis dome (North-South Axis) an d situated within the "Calcaires noirs" and the "Gypses moyens" respectivel y correlated to the "Dolomies de Mekraneb" and the "Dolomies de Rehach" wel l known on the Saharian Platform. The Rhaetian assemblage F6 corresponds to the association of Hoyenella inconstans-Agathammina austroalpina-Gandinell a falsofriedli, already identified in the Fkirine Fm. ("Dorsale Tunisienne" ). In the studied area, it is present within oolitic dolostones included in the thick evaporites of the Rheouis Fm., underlining the North-South Axis overthrust, just below the Liassic Nara Fm. dolomites. The F6 dolostones ca n be regarded as equivalent to the dolomites of the Saharian Zerzour Fm.