Seismic anisotropy in the mantle of a tectonically inverted extensional basin: A shear-wave splitting and mantle xenolith study on the western Carpathian-Pannonian region

• DOI: 10.1016/j.tecto.2022.229643
• Publication Date: 2022-11-13T22:35:12Z
• Authors: Nóra Liptai; Zoltán Gráczer; Gyöngyvér Szanyi; Sierd A.P.L. Cloe...; Bálint Süle; László E. Aradi; György Falus; Götz Bokelmann; Máté Timkó; Gábor Timár; Csaba Szabó; István J. Kovács
• Keywords: Seismic anisotropy; Shear wave splitting; Xenolith

Information on seismic anisotropy in the Earth's mantle can be obtained from (1) shear-wave splitting analyses which allow to distinguish single or multi-layered and delay time of fast slow polarized wave indicate its thickness, (2) studying peridotites where properties inferred lattice preferred orientation deformed minerals. We provide a detailed map western part Carpathian-Pannonian region (CPR), an extensional basin recently experiencing tectonic inversion, using data. then compare results with reported xenoliths characterize depth, regional differences anisotropic layer mantle. Mantle is different northern central/southern CPR. In part, lack azimuthal dependence split S-wave indicates layer, agrees xenolith data Nógrád-Gömör volcanic field. Systematic variations several stations central areas point multiple layers, may explained by two distinct subgroups described Bakony-Balaton Highland. The shallower probably has 'fossilized' lithospheric structure, representing former asthenospheric flow, whereas deeper one reflects structures attributed present-day convergent tectonics, also observed NW-SE orientations. Styrian Basin at rim CPR, are ambiguous as hint presence layers. Spatial coherency analysis parameters places center ~140–150 km depth under Western Carpathians, implies total thickness ~220–240 km. Thicknesses estimated give lower values, pointing heterogeneously distributed mineral deformation structures.