The Numidian Sequence between Guelma and Constantine (Eastern Tell, Algeria)


  • *This research is CNR contribution 2 ‘Role of the strike-slip and vertical tectonics in the Mediterranean Neogene’.


The Numidian Sequence represents one of the main tectono-stratigraphic units involved in the geological evolution of the Maghrebian orogen during the Upper Oligocene-Lower Miocene. Geo-structural aqalysis led to the reconstruction of tectonc-stratigraphic units and recognition of two main tectonic phases (Eocene and Lower Miocene). Sedimentological analysis of the studied sections has resulted in the distinction of arenaceous and conglomeratic facies generated by debris flows or high-density turbidity currents on a submarine slope, present within the pelitic-arenaceous and arenaceous-pelitic sequences which also contain slumped units in places.

Previous and new micropalaeontological data indicate Late Oligocene-Early Burdigalian ages for the Numidian sequences of the Constantine Mountains. On the basis of petrographic study the Numidian rocks can be classified as poorly sorted quartzarenites containing siliciclastic matrix. The overall petrographic data indicate that the Continental intercalaire (Hoggar, Tassili and Fezzan) and Series Pharusienne (Hoggar and Eglab) are possible supply areas for the Numidian quartz.