AFRICA/North African Phanerozoic 13 Figure Location of major North African sedimentary basins Lines indicate locations of cross sections in Figures 2, and Egypt Other natural resources that are exploited include Saharan fossil groundwater, phosphate, (see Sedimentary Rocks: Phosphates) and mineral ores and (vi) Oligo-Miocene rifting (see Tectonics: Rift Valleys) Infracambrian Extension and Wrenching Structural Evolution Most of North Africa has formed part of a single plate throughout the Phanerozoic with the exception of the Atlas Mountains which became accreted during Late Carboniferous and Tertiary collisional events North Africa can be structurally subdivided into a northern Mesozoic to Alpine deformed, mobile belt and the stable Saharan Platform (Figure 3) The latter became consolidated during the Proterozoic PanAfrican Orogeny (see Africa: Pan-African Orogeny), a collisional amalgamation between the West African Craton and numerous island arcs, Andean-type magmatic arcs, and various microplates The Late Neoproterozoic to Phanerozoic structural development of North Africa can be divided into six major tectonic (see Plate Tectonics) phases: (i) Infracambrian extension and wrenching; (ii) Cambrian to Carboniferous alternating extension and compression; (iii) mainly Late Carboniferous ‘Hercynian’ intraplate uplift; (iv) Late Triassic–Early Jurassic and Early Cretaceous rifting; (v) mid-Cretaceous ‘Austrian’ and Late Cretaceous–Tertiary ‘Alpine’ compression, The Late Neoproterozoic to Early Cambrian (‘Infracambrian’) in North Africa and Arabia was characterized by major extensional and strike-slip movements Halfgrabens and pull-apart basins developed, for example, in the Taoudenni Basin (SW Algeria) and in the Kufra Basin (SE Libya) These features are considered to be a westward continuation of an Infracambrian system of salt basins extending across Gondwana from Australia, through Pakistan, Iran and Oman, to North Africa Post-Infracambrian – Pre-Hercynian The structural evolution of North Africa between the Infracambrian extensional/wrenching phase and the Late Carboniferous ‘Hercynian Orogeny’ is complex Local transpressional and transtensional reactivation processes dominated as a result of the interaction of intraplate stress fields with pre-existing fault systems of varying orientation and geometry In some areas, such as the Murzuq Basin in SW Libya, these tectonic processes played an important role in the formation of hydrocarbon traps