A Geological History of the Turkana Basin

Abstract

The Turkana Basin preserves a long and detailed record of biotic evolution, cultural development, and rift valley geology in its sedimentary strata. Before the formation of the modern basin, Cretaceous fluvial systems, Paleogene lakes, and Oligo-Miocene volcano-sedimentary sequences left fossil-bearing strata in the region. These deposits were in part related to an early system of rift basins that stretched from Sudan to the Indian Ocean. The present-day basin has its origins in Pliocene tectonic developments of the modern rift, with subsidence making room for more than one kilometer of Plio-Pleistocene strata. Much of this sequence belongs to the Omo Group, richly fossiliferous sediments associated with the ancestral Omo River and its tributaries. Modern Lake Turkana has a record stretching back more than 200 thousand years, with earlier lake phases throughout the Plio-Pleistocene. The geologic history of the basin is one of dynamic landscapes responding to environmental influences, including tectonics, volcanic activity and climate.

New Fauna from Loperot Contributes to the Understanding of Early Miocene Catarrhine Communities

“…The Lokichar Basin Loperot sits on the western side of modern-day Lake Turkana, a rift lake along the East African Rift System (EARS) situated between the Kenyan and Ethiopian domes (Feibel 2011 ;Morley et al 1999a ) (Fig. 2 ).…”

“…2 ). As a result of Tertiary (as well as more recent) faulting, various different basins formed, including the Lokichar Basin, in which the site of Loperot sits (Feibel 2011 ). The Lokichar Basin is a north-south trending half graben that is ca.…”

“…The Lokichar Basin is separated from the neighboring Kerio Basin by a topographic high of gneissic basement (the Lokone Horst) (Hendrie et al 1994 ;Morley et al 1999b ). Sediment infill of the Lokichar Basin is on the order of 7 km and thickens to the west near the border fault (Feibel 2011 ;Morley et al 1999b ). Analysis of the basin sediments indicates Eocene through Late Miocene strata (Boschetto et al 1992 ;Joubert 1966 ;Morley et al 1999a ).…”

Ichthyofaunal diversity of the Omo-Turkana basin, East Africa, <span lang="EN-US">with specific reference to fish diversity within the limits of Ethiopian waters</span>

“…The Omo basin is part of the large Turkana system with a catchment area of 131,000-145,500 km 2 covering southwestern Ethiopia and northern Kenya (Feibel 2011;Velpuri et al 2012). The Turkana system essentially consists of the Omo-Gibe (or simply, Omo) River and Lake Turkana.…”

“…One of these, the Omo-Turkana basin, spans a large part of the southwestern Ethiopian highlands and northern Kenya (Feibel 2011;Velpuri et al 2012) (Figure 1). …”