I have worked extensively in and around a number of the East African Lakes, including Tanganyika, Malawi and Turkana. My main research to date centers on understanding how facies and their geometry vary as a function of climatic and tectonic setting. More recently, I am interested in how specific facies, which form critical ecosystems for a number of species, are influenced by anthropogenic changes.
1) Understanding the significance of taphonomy and time-averaging of the extensive shell beds that occur in Lake Tanganyika. Shells of the mollusks (Neothauma tanganyicense and Caelatura) pave large areas of Lake Tanganyika, and this substrate provides an ecological niche for a number of organisms, including sponges and shell-brooding Cichlid fish. Using surface samples and short cores we are attempting to understand how these shell beds originate and how they are maintained over long periods of time. There is also an important conservation component, because local deforestation and high rates of erosion of the adjacent lake margins is increasing the depositional load over these shell beds, and this may be affecting organisms living on the shell beds.
2) Using sediment cores from Lake Tanganyika we are documenting Holocene and recent changes in regional tropical climate, as well as human-caused land use change within the Tanganyika watershed. This work is in collaboration with Dr. Michael McGlue (University of Kentucky). Specifically we use a chemical extraction technique to isolate the clastic (lithogenic) fraction of sediment from cores and then analyze the grain size and chemistry of this siliciclastic component in order to better understand changes in lake conditions as well as to constrain how land-use change is impacting sedimentation in the lake and consequently affecting the lake’s ecosystem.
3) In collaboration with Drs. Gilby Jepson and Sarah George we are just beginning an NSF-funded project in which we will document and interpret spatial differences in rift-flank uplift and erosion along the Lake Tanganyika rift to better understand rift tectonics and rift initiation within that part of the rift. Rift systems evolve as the extensional faults grow and link through time. We will also be utilizing digital elevation models (DEMs) to analyze watersheds within footwall uplifts of different tectonic maturity in the Lake Tanganyika region to interpret how watershed morphology and river profiles change over space within a rift.