NEOGENE TECTONIC HISTORY OF THE SUB-BIBANIC AND M’SILA BASINS, NORTHERN ALGERIA: IMPLICATIONS FOR HYDROCARBON POTENTIAL
H. L. Kheidri*, R. S. Zazoun** and N. Sabaou+
*Sonatrach, Division Exploration, Bâtiment I. A.P, 35000, Boumerdès, Algeria.
**Sonatrach, Centre de Recherche et Développement, Avenue du 1er Novembre 35000, Boumerdès, Algeria.
+ BHP Billiton Petroleum, Neathouse Place, London, SW1V 1LH.
Corresponding author: nordine.sabaou@bhpbilliton.com
The southern Bibans region in northern Algeria is located in the external zone of the Tell fold-and-thrust belt. Field observations in this area together with seismic data integrated with previous studies provide evidence for a number of Tertiary deformation phases. Late Eocene Atlassic deformation was followed by Oligocene (?)-Aquitanian-Burdigalian compression, which was associated with the development of a foreland basin in front of a southerly-propagating thrust system. Gravity-driven emplacement of the Tellian nappes over the basin margin probably occurred during the Langhian-Serravallian-Tortonian. The Hodna Mountains structural culmination developed during the Miocene-Pliocene. Analysis of brittle structures points to continued north-south shortening during the Neogene, consistent with convergence between the African and Eurasian Plates.
The unconformably underlying Mesozoic-Cenozoic autochthonous sequence in this area contains two potential source rock intervals: Cenomanian-Turonian and Eocene. Reservoir rocks include Lower Cretaceous siliciclastics and Upper Cretaceous to Palaeogene carbonates. Structural style has controlled trap types. Thus traps in the Tell fold-and-thrust belt are associated with folds, whereas structural traps in the Hodna area are associated with reactivated normal faults. In the latter area, there is also some evidence for base-Miocene stratigraphic traps.