The Wonji Fault Belt (WFB), Main Ethiopian Rift, forms a network of faults oriented NNE-SSW with a Quaternary direction of extension oriented c. N95° E. Faults are spaced between 0.5 and 2 km, show a fresh steep scarp, recent activity and slip rates of up to 2.0 mm a−1. This high value of deformation along the rift floor with respect to the plate separation rates suggests that most of the active strain could be accommodated by magma-induced faulting within the rift. However, the mountain front morphology associated with a displacement of 300–400 m since the Middle Pleistocene, tilted-blocks, brittle-seismic fault rock fabric and historical earthquakes with M>6 support a tectonic origin of the Asela boundary fault. Therefore, we propose a model that considers the possible coexistence of both magmatic deformation at the rift floor and brittle faulting at the rift margin. We also report the data relative to a GPS network installed in December 2004, along two transects across the WFB, between Asela and the Ziway Lake.

Pizzi, A., Coltorti, M., Abebe, B., Disperati, L., Sacchi, G., Salvini, R. (2006). The Wonji Fault Belt (Main Ethiopian Rift): structural and geomorphological constraints and GPS monitoring. In The Afar Volcanic Province within the East African Rift System (pp. 191-207). London : Geological Society of London [10.1144/GSL.SP.2006.259.01.16].

The Wonji Fault Belt (Main Ethiopian Rift): structural and geomorphological constraints and GPS monitoring

Coltorti M.
Membro del Collaboration Group
;
Disperati L.
Membro del Collaboration Group
;
Sacchi G.
Membro del Collaboration Group
;
Salvini R.
Membro del Collaboration Group
2006-01-01

Abstract

The Wonji Fault Belt (WFB), Main Ethiopian Rift, forms a network of faults oriented NNE-SSW with a Quaternary direction of extension oriented c. N95° E. Faults are spaced between 0.5 and 2 km, show a fresh steep scarp, recent activity and slip rates of up to 2.0 mm a−1. This high value of deformation along the rift floor with respect to the plate separation rates suggests that most of the active strain could be accommodated by magma-induced faulting within the rift. However, the mountain front morphology associated with a displacement of 300–400 m since the Middle Pleistocene, tilted-blocks, brittle-seismic fault rock fabric and historical earthquakes with M>6 support a tectonic origin of the Asela boundary fault. Therefore, we propose a model that considers the possible coexistence of both magmatic deformation at the rift floor and brittle faulting at the rift margin. We also report the data relative to a GPS network installed in December 2004, along two transects across the WFB, between Asela and the Ziway Lake.
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Pizzi, A., Coltorti, M., Abebe, B., Disperati, L., Sacchi, G., Salvini, R. (2006). The Wonji Fault Belt (Main Ethiopian Rift): structural and geomorphological constraints and GPS monitoring. In The Afar Volcanic Province within the East African Rift System (pp. 191-207). London : Geological Society of London [10.1144/GSL.SP.2006.259.01.16].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/25490