Abstract
The Northern Kenya Rift is an important natural laboratory for understanding continental rifting processes. However, much of the current understanding of its geological evolution is based on surface outcrops within footwall highs due to a lack of subsurface geological constraints. In this paper, we present an investigation of the Cenozoic stratigraphy and volcano-tectonic relationship of the volcanic sequences within the Turkana Depression (namely the North Lokichar, North Kerio and Turkana Basins). We integrate regional seismic reflection data collected as part of ongoing petroleum exploration in the area with lithological and biostratigraphic data from new wells that were drilled in 2014 and 2015 (Epir-1 and Emesek-1). This has allowed linking and extrapolation of the detailed stratigraphy of the paleontologically important Lothagam site to the volcanic sequences within the Napedet Hills, North Lokichar, North Kerio and Turkana Basins. The site of the Plio-Pleistocene-age Turkana Fault, which separates the North Lokichar Basin from the Turkana and North Kerio Basins, appears previously to have acted as a focus of Middle Miocene volcanism c . 5 Ma prior to the main period of movement on the fault. Our study highlights how subsurface and outcrop information can be combined to give a more in-depth knowledge of the magmatic history within rift basins.
Highlights
IntroductionThe East African Rift system (EARS) (Fig. 1) continues to provide an important natural laboratory to understand rift processes and interlinked volcano-tectonic interactions within sedimentary basins (e.g. Ebinger and Sleep 1998; Morley et al 1999; Vetel and Le Gall 2006; Muirhead et al 2016; Ebinger et al 2017; Ragon et al 2018; Morley 2020)
Correlation across the Turkana area and further afield in the East African Rift system (EARS) is complicated by the sedimentary and volcanic history seen at outcrop within the present-day landscape, as this is often only a partial record that varies depending on local tectonics (McDougall and Brown 2009) with uplift of fault footwalls often eroding large thicknesses of pre-rift stratigraphy
The primary aim of this paper is to present an integrated seismicwell-outcrop stratigraphic assessment of the volcanic sequences across the North Lokichar, North Kerio and Turkana Basins, allowing for better constraint of the surface to subsurface volcanic stratigraphy within the Turkana Depression
Summary
The East African Rift system (EARS) (Fig. 1) continues to provide an important natural laboratory to understand rift processes and interlinked volcano-tectonic interactions within sedimentary basins (e.g. Ebinger and Sleep 1998; Morley et al 1999; Vetel and Le Gall 2006; Muirhead et al 2016; Ebinger et al 2017; Ragon et al 2018; Morley 2020). Correlation across the Turkana area and further afield in the EARS is complicated by the sedimentary and volcanic history seen at outcrop within the present-day landscape, as this is often only a partial record that varies depending on local tectonics (McDougall and Brown 2009) with uplift of fault footwalls often eroding large thicknesses of pre-rift stratigraphy. The eastern branch forms the Kenyan and Ethiopian Rifts, in which NW Kenya sits within an area commonly referred to as the Turkana Depression (Figs 1 and 2). The North Kerio Basin (Fig. 3), lies east of the Napedet (known in Kenya locally as Napudet), Kamutile and Auwerwer Hills and is bounded to the west by a series of easterly dipping faults, including the Lokhone Fault, Napedet Fault and Lothagam Fault, which forms a prominent fault escarpment that bounds the uplifted footwall block of Lothagam (Fig. 3)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
