A new look at Gregory's Rift: The structural style of continental rifting

Abstract

We distinguish three major detachment systems and intervening accommodation zones in the central Gregory Rift of east Africa and point out that the geometry seen here is similar to that of other modern and ancient continental rift systems. The asymmetry of the rift (half‐graben form) alternates along the rift axis, with corresponding reversals in the polarity of the extensional detachment systems. This may be important to the overall understanding of rift tectonics, as the Gregory Rift is associated with an unusually voluminous volcanogenic province, regional doming, and other characteristics of continental “hot spots” (and their inferred subcontinental mantle plumes). The fact that all continental rifts appear to have very similar structural geometries, yet few are actually associated with these hot spot characteristics supports the contention that hot spots are only locally associated with and do not significantly affect the shallow geometry of continental rifting.