To gain a deeper understanding of the extensive and varied lithospheric deformations beneath northern Oman, we examine seismic anisotropy in this region using splitting analysis of teleseismic shear wave data. Our study utilizes data from a dense network consisting of 13 permanent and 45 temporary seismic stations, which were operational for approximately 2.5 years starting from 2013. By examining the azimuthal distribution of shear wave splitting (SWS) parameters, we are able to divide the study area into three sub-regions. The stations located to the west of the Hawasina window exhibit relatively azimuthally invariant SWS parameters suggesting a single anisotropic layer. On the other hand, most of the stations located in the central and eastern regions display a 90-degree periodicity versus back-azimuth, indicating the presence of depth-dependent anisotropy. The General NW-SE trend of the Fast Polarization Directions (FPDs), one-layer/upper layer FPDs in the east and one-layer FPDs in the west, is concordant with the strike of the structures resulting from the collision between the continental and oceanic plates. Notably, a distinct contrast in the SWS parameters is observed at Semail Gap Fault Zone (SGFZ), suggesting that the SGFZ can be a geological border for the mafic intrusive emplacement from the east. Furthermore, the fast axes of the lower layer exhibit an NE-SW trend, which may be indicative of the large-scale mantle flow resulting from the present-day plate motion.

The presence of the Etendeka flood basalts in northwestern Namibia is taken as evidence for the activity of the Tristan da Cunha mantle plume during the breakup process between Africa and South America. We investigate seismic anisotropy beneath NW Namibia by splitting analysis of core-refracted teleseismic shear waves (XKS phases) to probe mantle flow and lithospheric deformation related to the tectonic history of the region. The waveform data were obtained from 34 onshore stations and 12 Ocean Bottom Seismometers. The results presented here are from joint splitting analysis of multiple XKS phases. The majority of the fast polarization directions (FPDs) exhibit an NE-SW orientation consistent with a model of large-scale mantle flow due to the NE motion of the African plate. No evidence for a direct effect of the mantle plume is observed. In the northern part, we observe NNW-SSE-oriented FPDs that is likely caused by shallow lithospheric structures.

A common deviation from typical subduction models occurs when thrust sheets of oceanic-crust and upper-mantle rocks are emplaced over more buoyant continental lithosphere. The archetypal example of ophiolite obduction is the Semail ophiolite in the United Arab Emirates (UAE)-Oman orogenic belt, formed and obducted onto the Arabian continental margin during the Late Cretaceous. The Strait of Hormuz syntaxis, the northern extent of the UAE-Oman mountains, marks the transition from ocean-continent convergence in the Gulf of Oman to continental collision along the Zagros Mountains. Based on new seismic data from a focused recording network, we infer crustal and mantle deformation in the northeastern corner of the Arabian plate (including the southern Zagros and the UAE-Oman mountains), using observations from anisotropic tomography and shear-wave splitting measurements. We recover a change of ~90˚ in the axis of fast-anisotropic orientations in the crust from the Zagros to the UAE-Oman mountain belt, consistent with the dominant strike of the orogenic belts. We also find evidence for localized fossil deformation in the lithospheric mantle underlying the UAE-Oman mountain range, possibly related to stress-induced tectonism triggered by underthrusting of the proto-Arabian continental margin beneath the overriding Semail ophiolite. These orientations, averaging 15˚ anticlockwise, provide the first geophysical verification of geological