Upper mantle anisotropy of southeast Arabia passive margin [Gulf of Aden northern conjugate margin], Oman
In this study, we used data recorded by two consecutive passive broadband deployments on the Gulf of Aden northern margin, Dhofar region, Sultanate of Oman. The objective of these deployments is to map the young eastern Gulf of Aden passive continental margin crust and upper mantle structure and rheology. In this study, we use shear-wave splitting analysis to map lateral variations of upper mantle anisotropy beneath the study area. In this study, we found splitting magnitudes to vary between 0.33 and 1.0 s delay times, averaging about 0.6 s for a total of 17 stations from both deployment periods. Results show distinct abrupt lateral anisotropy variation along the study area. Three anisotropy zones are identified: a western zone dominated by NW–SE anisotropy orientations, an eastern zone dominated with NE–SW anisotropy orientations, and central zone with mixed anisotropy orientations similar to the east and west zones. We interpret these shorter wavelength anisotropy zones to possibly represent fossil lithospheric mantle anisotropy. We postulate that the central anisotropy zone may be representing a Proterozoic suture zone that separates two terranes to the east and west of it. The anisotropy zones west and east were being used indicative of different terranes with different upper mantle anisotropy signatures.
KeywordsGulf of Aden Arabia SKS Shear-wave splitting Anisotropy Passive continental margin
The authors are grateful to all who have contributed directly or indirectly to this work. This work was supported by NERC grant NE/C514031/1 and a Royal Society travel grant to the first author. GDR Margins contribution.
- Bellahsen N, Fournier M, d’ Acremont E, Leroy S, Daniel JM (2006) Fault reactivation and rift localization: northeastern Gulf of Aden margin. Tectonics 25. doi: 10.1029/2004TC001626
- Beydoun Z (1996) Sedimentary basins of the Republic of Yemen: their structural evolution and geological characteristics. Rev Inst Fr Petrole Geol 51(51):13Google Scholar
- Coleman RG (1981) Tectonic setting for ophiolite obduction in Oman. J Geophys Res 86(B4):12Google Scholar
- Glennie KW, Boeuf MGA, Clarke MWH, Moody-Stuart M, Pilaar WFH, Reinhardt BM (1973) Late Cretaceous nappes in Oman mountains and their geologic evolution. AAPG Bulletin 57:22Google Scholar
- Husseini MI (1988) The Arabian Infra-Cambrian extensional system. Tectonophysics 8:11Google Scholar
- Kaviani A, Hatzfeld D, Paul A, Tatar M, Priestley K (2009) Shear-wave splitting, lithospheric anisotropy, and mantle deformation beneath the Arabia-Eurasia collision zone in Iran. Earth Planet Sci Lett 286. doi: 10.1016/j.epsl.2009.07.003
- Leroy S, Gante P, Fournier M, d’Acremont E, Patriat P, Beslier MO, Bellahsen N, Maia M, Blais A, Perrot J, Al-Kathiri A, Merkouriev S, Fleury JM, Ruellan PY, Lepvrier C, Huchon P (2004) From rifting to spreading in the eastern Gulf of Aden: a geophysical survey of a young oceanic basin from margin to margin. Terra Nova 16:8CrossRefGoogle Scholar
- Leroy S, Lucazeau F, d’Acremont E, Watremez L, Autin J, Rouzo S, Bellahsen N, Tiberi C, Ebinger C, Beslier M-O, Perror J, Razin P, Rolandone F, Sloan H, Stuart G, Al-Lazki A, Al-Toubi K, Bache F, Bonneville A, Goutorbe B, Huchon P, Unternehr P, Khanbari K (2010b) Contrasted styles of rifting in the eastern Gulf of Aden: a combined wide-angle, multichannel seismic, and heat flow survey. GC Res Lett 11(7):14. doi: 10.1029/2009GC002963 Google Scholar
- Loosveld R, Bell A, Teerken J (1996) The tectonic evolution of Interior Oman. Geo Arab 1:24Google Scholar