Reconnaissance Geology of the Amaro Horst, Southern Ethiopian Rift

摘要

The Amaro horst is a 90-km by 25-km block of sialic crust uplifted 1.5 km above the axis of the main Ethiopian rift, near its southern termination. The Amaro horst resembles the famous Ruwenzori horst of the Western rift, but additionally the former has had a Neogene-Quaternary volcanic history that reveals episodic uplift of the horst from the axis of a bilaterally downwarping-downtilting rift floor. Vertical forces that produced normal faults uplifted the horst to stratigraphic elevations higher than the plateaus outside the rift.