Blue Nile Incision on the Ethiopian Plateau: Pulsed Plateau Growth, Pliocene Uplift, and Hominin Evolution Nahid DS Gani*, M
Blue Nile incision on the Ethiopian Plateau: Pulsed plateau growth, Pliocene uplift, and hominin evolution Nahid DS Gani*, M. Royhan Gani*, Energy & Geoscience tonically active landscapes, including the Himalayas, Rockies, Alps, Pyrenees, Andes, and Southern Alps (New Zealand). The Institute, University of Utah, 423 Wakara Way, Suite 300, erosional history of the Colorado (e.g., Pederson et al., 2002; Salt Lake City, Utah 84108, USA; Mohamed G. Abdelsalam, McMillan et al., 2006, and references therein) and the Tibetan Geological Sciences and Engineering, University of Missouri, plateaus (e.g., Clark et al., 2004; Schoenbohm et al., 2004, and 123 McNutt Hall, Rolla, Missouri 65409, USA references therein), both situated within collisional orogenic belts, are well studied. Conversely, studies of the erosional his- tory of the non-orogenic Ethiopian Plateau are few and pre- liminary (McDougall et al., 1975; Weissel et al., 1995; Pik et al., ABSTRACT 2003). Relative to other elevated regions where direct glacial The 1.6-km-deep Gorge of the Nile, a rival of the Grand Can- erosion is pronounced, the Ethiopian Plateau is least affected yon, resulted from the deep incision of the Blue Nile drainage into by Cenozoic global cooling and/or Pleistocene glacial cycles the uplifted Ethiopian Plateau. Understanding the incision history because of its location close to the equator (cf. Molnar and of the plateau is crucial to unraveling the Cenozoic tectonocli- England, 1990). Moreover, because of its non-orogenic setting, matic evolution of the region, particularly because the region has tectonic exhumation of the Ethiopian Plateau is insignificant. long been used as a natural laboratory to understand the geody- Therefore, river incision and plateau uplift (tectonic and/or iso- namics of continental rifting and the evolution of hominins.
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