The East African Rift System (EARS) includes a northern segment that is more volcanically influenced than regions to the south. To explore the roles of climate, tectonism, and volcanism and the architecture of sedimentary deposits in rift basins, this manuscript by Mtelela and others provides a sedimentologic investigation of the Pleistocene–Holocene upper Lake Beds, the uppermost stratigraphic unit exposed throughout the Rukwa Rift Basin in southwestern Tanzania. Integrating geologic mapping, lithofacies analysis, petrographic microscopy, scanning electron microscopy, and radiocarbon dating reveal alternating stacking patterns of landward- and basinward-stepping alluvial to fluvial channel, deltaic, and profundal lacustrine strata, bounded by unconformities. Sequence development in this rift basin is interpreted to be controlled largely by base-level changes drive by interplay between climate change and sediment supply, but was influenced by episodic volcanism in the Rungwe Volcanic Province. Understanding these types of linkages is central to efforts in evaluating the resource potential of rift basins; in this basin, it also provides a foundational context for interpretation of regional paleoclimate and paleoenvironmental setting of vertebrate fossils.
Interplay of structural, climatic, and volcanic controls on late Quaternary lacustrine–deltaic sedimentation patterns in the western branch of the East African Rift System, Rukwa Rift Basin, Tanzania by Cassy Mtelela, Eric M. Roberts, Robert Downie, and Marc S. Hendrix