HR: 0830h
AN: S51C-0072    [PDF]
TI: Atypical Normal Faults Morphology in the Main Ethiopian Rift
AU: * Gloaguen, R
EM: gloaguen@geo.tu-freiberg.de
AF: TU "Bergakademie" Freiberg, Institut fuer Geologie B. v-Cotta Strasse 2, Freiberg, 09599 Germany
AU: Kurz, T
EM: tkurz@student.tu-freiberg.de
AF: TU "Bergakademie" Freiberg, Institut fuer Geologie B. v-Cotta Strasse 2, Freiberg, 09599 Germany
AU: Ebinger, C
EM: c.ebinger@gl.rhul.ac.uk
AF: Royal Holloway University of London, Geology Department, Egham, TW200EX United Kingdom
AU: Casey, M
EM: m.casey@earth.leeds.ac.uk
AF: University of Leeds, School of Earth Sciences, Leeds, LS29JT United Kingdom
AU: Abebe, B
EM: bekelino@yahoo.com
AF: Addis Ababa University, Department of Geology, Addis Ababa, PO 1176 Ethiopia
AB: The seismically active northern part of the Main Ethiopian Rift (MER) is one of few sites worldwide showing the transition between continental and oceanic rifting. The northern MER has been active since ~12 Ma, with increased activity in a narrow belt of faulting and magmatism since 2 Ma. This approx 20 km-wide zone of magmatic construction and closely-spaced faults lies within the central 70 km-wide rift valley bounded by relatively inactive border faults. Within these segments we observe an intimate relationship between the generation of faults and the localisation of basaltic flows and eruptive centers. The atypical morphology of these faults can be quantitatively described on Displacement/Length (D/L) and cumulative dimensions frequency diagrams. The faults are very long (up to 20 kms) with relatively extremely small vertical displacements (10-20 m) and a relatively large horizontal displacements (1-20 m), composed of numerous segments, flat hanging-walls, and convex foot-walls. These patterns suggest that the extension on the faults is not directly related to the fault lengths; the lateral growth of a fault is due to hard linkage of segments which origin maybe linked to low-depth dykes.
DE: 8010 Fractures and faults
DE: 8040 Remote sensing
DE: 8105 Continental margins and sedimentary basins
SC: Seismology [S]
MN: 2003 Fall Meeting