CAREER: Reconciling the Turkana Basin's timeline utilizing luminescence geochronology to reduce sedimentary gaps from the last million years

The Turkana Basin of northern Kenya, often referred to as East Africa’s cradle of humankind, preserves one of the region’s most important records of human and landscape changes spanning deep time. Yet much of the last one million years of that record remains poorly understood because many sedimentary deposits are only sporadically preserved across the basin and the volcanic ash layers traditionally used to date older deposits have not been identified. These persistent gaps limit the ability to precisely place key fossils and archaeological horizons within the regional human development timeline. The gaps also complicate understanding of how animals and hominins responded to past environmental change. This project combines renewed geological mapping, detailed sedimentary analyses, and advanced age-dating methods to reconstruct how Lake Turkana and the surrounding landscape changed through time. By establishing when major landscape changes occurred, the research will help to better understand how water resources shifted across the basin and how these changes influenced ecosystems and past populations. The technical component of the project will combine luminescence geochronology, stratigraphic mapping, sedimentology, petrography, and Bayesian age-depth modeling to investigate sedimentary deposits spanning the Middle Pleistocene to the Early Holocene. The research addresses three interconnected questions. First, it will determine the duration and distribution of unconformities within the Turkana Basin and test whether apparent gaps in the sedimentary record reflect long periods of erosion and non-deposition or whether previously unrecognized deposits preserve a more continuous archive of landscape history. Second, it will compare multi-mineral and multi-protocol luminescence dating approaches to improve chronological accuracy across a broad range of sedimentary environments. Third, it will integrate new age-estimates with facies analysis and stratigraphic correlations to reconstruct changes in lake extent, shoreline migration, and fluvial systems through time. Together, this work will produce the first basin-wide chronologic framework for the Middle Pleistocene to Early Holocene record of Turkana and provide new insights into the interactions among tectonic activity, hydrology, sedimentation, landscape evolution and human presence within the East African Rift. The project’s research and educational goals will be integrated through a transdisciplinary training program designed to foster synergies among geoscience, science communication, and creative disciplines. Students and early-career researchers will gain field and laboratory experience while working with the Turkana Basin Institute, educators, and community and industry partners to develop place-based learning experiences and public-facing science programs. These activities will prepare the next generation of scientists and STEM workforce. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.