Le Carbonifère Marin Du Sahara Algérien

Devonian stratigraphy and depositional environments in the southern Illizi Basin (Algerian Sahara)

“…Because the majority of the reservoirs is located in Palaeozoic rocks, an enormous amount of stratigraphic and sedimentologic data about this period accumulated, but unfortunately remained unaccessible to non-oil geologists. Some results were published by Legrand (1967Legrand ( , 1983 and Moussine-Pouchkine (1976). Later summaries (Askri et al, 1995;Fabre et al, 2005;Zeroug et al, 2007) are valuable overviews, in particular regarding the hydrocarbon systems.…”

“…Twenty-five kilometers farther east, Middle Devonian strata disappear completely, and Upper Devonian shales rest directly on Lower Devonian sandstones (Chaumeau et al, 1962;Legrand, 1967;Sonatrach-Beicip, 1974-1975 Illizi and Fort Tarat).…”

The Upper Silurian of Touat (Algerian Sahara) and its fauna

“…Above them, it is possible that the first level of ferruginous siltstone with Tentaculoidea is of Devonian, more precisely Lochkovian (g4) age, in a Gedinian facies. Earlier fossil lists (Legrand 1968) indicated a Pragian age for the upper part of the Touat Sandstone Formation.…”

“…The Fenourine Clay Formation (Legrand 1962(Legrand , 1967(Legrand , 1985. Only its upper part (about 150 m and not 200 m as previously measured) is visible, and this consists mainly of argillaceous siltstones with some interbedded calcareous sandstones, sandy limestones and fine-grained sandstone.…”

“…The Touat Sandstone Formation (Legrand 1962(Legrand , 1967(Legrand , 1985. This is a thick (170 m) unit of silty claystones with interbedded sandstones and a prominent sandstone at the top.…”