Focusing on the passive continental margin basins with similar structural and sedimentary characteristics in
Morocco and Western Sahara offshore areas, this paper conduct research on basin evolution, petroleum geological
characteristics, and resource potential, and point out the direction of oil and gas exploration. Morocco-Western Sahara
passive continental margin basins are composed of Aaium Tarfaya Basin, Souss Trough, Essaouira Basin and Doukkala
Basin. These basins experienced three stages of tectonic evolution, including pre-rift stage, rift stage and post-rift
subsidence stage. The pre-rift stage is characterized by the passive continental margin evolution from Cambrian to Early
Carboniferous and uplift from Late Carboniferous to Permian. Rifting commenced in Triassic and continued to Early
Jurassic. The Triassic and Lower Jurassic terrestrial-marginal marine strata are separated from Paleozoic strata by the
Hercynian unconformity. The post-rift stage prevailed from Middle Jurassic to present day, which can be divided into
thermal subsidence period of Middle Jurassic to Cretaceous and uplift period of Paleogene to Neogene . Multiple sets of
source rocks, reservoirs and a variety of trap types are developed due to the basin structural evolution and sea level
change. The most important source rock is post-rift Jurassic-Cretaceous marine mudstone, and the main reservoir is
Jurassic-Cretaceous carbonate rock and clastic rock reservoirs. The trap types are mainly structural traps and structurallithologic
traps formed under the salt tectonics mechanism. Three main reservoir forming assemblages are divided in the
Moroccan -Western Sahara passive continental margin basins, with the Jurassic and Cretaceous-Neogene reservoir forming
assemblages being the most important. Jurassic carbonate rock and Cretaceous Albian-Cenomanian turbidite sandstone
are the current key exploration fields in this area. Stratigraphic lithologic traps formed by Cretaceous salt tectonics and
slope fan in deep water area may be the future exploration potential area. |