ABSTRACT
Rukwa Rift located between the Tanganyika and Nyasa rifts forms part of the western arm of the East African Rift System (EARS). The eastern bounding fault of the Rukwa Basin (RB) normally designated as a Border Fault (BF), show relatively lower relief than the fault on the ramping side of the basin. This behavior in part contrasts RB from the rest of the basins in the Western Rift, characterized by high flank uplift on the side of the BF. This chapter examines the uplift history of RB using apatite Fission-Track (FT) analysis. The NW-SE trending Rukwa Rift traverses a similarly trending Early Proterozoic Ubendian Belt (UB). Track-Lengths (TL), show negatively skewed distributions suggesting a steady cooling as opposed to rapid exhumation, where tracks would show more uniform lengths. Correcting the FT ages for unannealing, suggests that uplift was initated at 300 Ma an age which mark the beginning of Karoo tectonic activities in the region.
