HR: 0800h
AN: T41A-0351    [Abstracts]
TI: Evidence of partial melting beneath the passive margin of the Gulf of Aden from a joint analysis of gravity and seismology
AU: Basuyau, C
EM: clemence.basuyau@lgs.jussieu.fr
AF: University Paris 6, Laboratoire de tectonique, Case 129, 4 Place jussieu, Paris cedex 05, 75252, France
AU: Tiberi, C
EM: tiberi@ccr.jussieu.fr
AF: University Paris 6, Laboratoire de tectonique, Case 129, 4 Place jussieu, Paris cedex 05, 75252, France
AU: * Leroy, S
EM: sylvie.leroy@lgs.jussieu.fr
AF: University Paris 6, Laboratoire de tectonique, Case 129, 4 Place jussieu, Paris cedex 05, 75252, France
AU: Ebinger, C
EM: cebinger@earth.rochester.edu
AF: Department of Earth and Environmental Sciences, University of Rochester, 227 Hutchison Hall, Rochester, NY 14627, United States
AU: Al-Lazki, A
EM: lazki@squ.edu.om
AF: University Sultan Qaboos, P.O. Box 50, Al-Khoudh, Muscat, PC123, Oman
AU: Al-Tobi, K
EM: kitobi@squ.edu.om
AF: University Sultan Qaboos, P.O. Box 50, Al-Khoudh, Muscat, PC123, Oman
AB: Rifting processes though extensively studied are still not well known. Nevertheless geophysical studies can provide new insight into the mechanisms of continental opening. The Gulf of Aden is a young narrow and obliquely opening oceanic basin formed during the Olig-Miocene. Its conjugate margins are well preserved beneath a thin post-rift sedimentary cover.It thus makes it an ideal region to study the processes of rifting and continental lithospheric break-up. In 2003 and 2005, numerous teleseismic earthquakes were recorded at twenty-nine broadband seismic stations in Dhofar (Oman) in order to study the northern margin of the Gulf of Aden. In this work, we used a joint inversion of teleseismic P-wave delay times and Bouguer anomaly. We obtain velocity ans density models that shows (1) crustal heterogeneities that match to the main geological features at the surface, (2) the presence of two low velocity anomalies in the continuation of Socotra and Alula Fartak fracture zones that appear at 60 km depth and may extend to at least 200 km, (3) gravity edge effect on the margin. The S wave tomography results are consistent with the joint inversion ones, and evidence partial melting within the two deep velocity anomalies. These results which suggest that the Afar hotspot has an influence up to the Dhofar will be discussed.
DE: 7203 Body waves
DE: 7218 Lithosphere (1236)
DE: 7270 Tomography (6982, 8180)
DE: 8109 Continental tectonics: extensional (0905)
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting