The Mesozoic succession of Dire Dawa, Harar Province, Ethiopia

The Mesozoic succession of Dire Dawa, Harar Province, Ethiopia, consists of a lower fluviatile sandstone (Adigrat Sandstone); an intermediate carbonat e-marly unit, formerly called Antalo Limestone; and an upper fluviatile san dstone (Amba Aradam Formation). This study has shown that the intermediate unit consists of four different formations grouped into two depositional se quences. These sequences and their boundaries, Middle-Late Jurassic in age, are well correlated with sequences recognised throughout East Africa and a large part of Yemen. The base of the lower sequence (Antalo Supersequence) is time-transgressive (Pliensbachian to Oxfordian) and is the result of th e first flooding of this sector of the Gondwana continent during the Mesozo ic. The second major sequence boundary is also time-transgressive and corre sponds to an abrupt deepening of East Africa and southern Arabia shallow wa ter ramps and carbonate platforms, a collapse most probably related to the separation of Madagascar from Africa. A major tectonic event occurred in Ea rly Cretaceous from northern Ethiopia to Yemen, and southern Ethiopia and S omalia. This vast uplift, testified by faults and angular unconformities, w as followed by deposition of fluviatile sediments over the entire region. ( C) 2001 Elsevier Science Limited. All rights reserved.