The Structural Evolution of the Berkine Basin, Algeria
Stephen McKenna1, Richard J. Hedley1
(1) Anadarko Algeria Company Limited, Uxbridge, United Kingdom
Anadarko has been successfully exploring the Berkine Basin of Algeria for more than a decade and has access to an extensive seismic and well database. Interpretation of these data suggests the Phanerozoic rocks record a polyphase tectonic evolution.
The Late Palaeozoic to Recent evolution of the Berkine Basin is closely related to kinematic plate movements along the margins of the African Craton. The first effects of the collision of Laurasia with Africa occurred during the Late Devonian and result in major changes to the sediment provenance areas in the Berkine Basin. Within the Berkine Basin the effects of the Hercynian Orogeny resulted in uplift and tilting of the Palaeozoic intervals followed by erosion.
Major extensional rifting occurred in Late Triassic/Liassic times related to break-up of Pangea and the opening of the Central Atlantic. During the drift phase, in Middle Jurassic - Early Cretaceous, Africa moved eastwards relative to the Iberian plate, resulting in sinistral movement along the Newfoundland-Gibraltar Fracture Zone (NGFZ). The stresses resulted in transpresssional folds with NW-SE trending axes (Austrian Event). Opening of the North Atlantic, during Late Cretaceous-Oligocene, changed the relative movement of Iberia and Africa along the NGFZ resulting in dextral wrench tectonics with a NW-SE compressional component (Pyrenean Event). The Berkine Basin was uplifted, Palaeogene sediments were eroded and some pre-existing NE-SW oriented fault zones were structurally inverted. Finally, the effects of Late Tertiary (11-5 ma) Alpine collision of Africa into Europe were felt in the Berkine Basin and resulted in mild regional tilting and gentle inversion.