SEES Seminar: "The Okavango Rift in Botswana"

The Okavango Rift (OR) in Botswana is part of the southwestern extension of the more mature East African Rift System. The OR is the youngest part of the East African Rift System and is currently at the beginning stages of becoming a continental rift. Thus, there have been numerous questions if the OR is actually a contenental rift. There are no surface volcanic rocks, limited evidence of extension and no plateau uplift. To aid in determining if the OR is an active rift, a series of geophysical experiments have been conducted to study the lithospheric structure of the OR. These studies include active and passive seismic, gravity, magnetics and magnetotellurics. The studies have shown that underneath the OR, the lithosphere and asthenosphere display the classic signatures of a continental rift including: thinned crust, lower density and seismic velocities. Higher electrical conductivities in the lithosphere indicate a rising warm asthenosphere. Additionally, a magnetic analysis indicated that the Curie Isothermal depths are elevated, again agreeing with the other geophysical results. Thus, the OR is considered to be in the initial stages of continental rift evolution. The future extension will create rift-related grabens and magmatic activity will reach the surface.

Dr. Kevin Mickus, distinguished professor of geology at Missouri State University specializes in geophysical methods. He studies Earth's tectonic environment to explore for water, mineral and geothremal resources.

Free