Lake Tanganyika: A Miocene-Recent Source-to-Sink Laboratory in the African Tropics

Understanding source-to-sink processes in continental sedimentary environments has been a long-term goal of the greater STEPPE community. We propose to investigate these processes through the study of an ancient tropical rift lake, which faithfully records profound signals of tectonics, climate variability, and surface processes in a long-duration and high-continuity sedimentary archive. The sedimentary deposits of extant tropical lacustrine rift basins are unrivaled archives of environmental history and represent an increasingly important component of the global petroleum source-rock endowment. Historically, stratigraphic prediction in these depositional systems has been a major challenge, in part because key linkages in the source-to-sink continuum for low-latitude rifts have only been considered conceptually. Accordingly, the controls shaping the stratigraphic record and its transitions at multiple temporal and spatial scales remain poorly resolved. The STEPPE workshop we propose will begin to address this knowledge gap by bringing together inter-disciplinary experts to examine Lake Tanganyika (East Africa) as a natural source-to-sink laboratory, whose intact depositional record likely spans the Miocene to present. We intend to focus discussions around geodynamic, atmospheric, hydrologic, and biological processes affecting the Tanganyika hinterland that influence sediment generation and transport, as well as the limnological and depositional processes influencing stratal architecture and the composition of sediment. The goal is to lay the framework for deconvolving forcing mechanisms from the depositional signal, primarily through the application of new analytical techniques, integration of large digital datasets, and process modeling. Lake Tanganyika is widely considered to be the premier target to recover a long-term, high resolution record of tropical climate, evolutionary biology, and rift tectonics via scientific drilling, and it is also an active frontier petroleum basin. Thus the outcome of this workshop will be of broad interest to the STEPPE community. Workshop participants will include students, industry scientists, and geoscientific representatives from Lake Tanganyika’s riparian nations. The workshop is designed to generate new pre-drilling site survey and workshop proposals to NSF and ICDP, respectively.