Complex Seismic Anisotropy and Mantle Dynamics beneath Turkey
Seismic anisotropy is an unambiguous property of the deep Earth that is often detected through shear wave splitting (SWS) and anisotropic receiver function (RF) techniques, which are then used to infer the lithospheric and asthenospheric deformational structure. The Anatolian plate and its associated Mediterranean, Eurasian, and Arabian plate boundaries represent the consequences of a variety of convergent and transform tectonic regimes; these boundaries are thus well-suited for studying seismic anisotropy related to subduction, orogenic, and strike-slip processes. We apply a joint SWS and RF analysis to identify the magnitude and orientation of deformation associated with lithosphere-asthenosphere coupling beneath the Anatolian plate system as well as intra-plate fossil fabrics resulting from ancient and ongoing collision. SWS analysis reveals the existence of complex anisotropic fabrics beneath the Anatolian region, where the upper-layer fast orientations are either parallel to strike-slip faults or orthogonal to reverse faults. Strongly oriented NE-SW lower-layer fast orientations suggest that they originate from slab-modulated flow in the mantle wedge overlying the northward-subducting African plate. The results of the RF analysis show that the fast orientations are spatially variable but are generally consistent with crustal fabrics developed mostly through intensive faulting and are possibly associated with sub-vertical lower crustal shear zones.
A. A. Lemnifi et al., "Complex Seismic Anisotropy and Mantle Dynamics beneath Turkey," Journal of Geodynamics, vol. 112, pp. 31-45, Elsevier, Dec 2017.
The definitive version is available at https://doi.org/10.1016/j.jog.2017.10.004
Keywords and Phrases
African plate; Arabian plate; Faulting; Lithosphere; Mantle; S-wave; Seismic anisotropy; Shear zone; Strike-slip fault; Tectonic setting; Wave splitting; Turkey; Dynamics of lithosphere and mantle; Planetary interiors; Receiver function; Shear wave splitting
International Standard Serial Number (ISSN)
Article - Journal
© 2017 Elsevier, All rights reserved.
01 Dec 2017