The lithospheric shear-wave velocity structure of Saudi Arabia: Young volcanism in an old shield
KAUST DepartmentEarth Science and Engineering Program
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AbstractWe investigate the lithospheric shear-wave velocity structure of Saudi Arabia by conducting H-κ stacking analysis and jointly inverting teleseismic P-receiver functions and fundamental-mode Rayleigh wave group velocities at 56 broadband stations deployed by the Saudi Geological Survey (SGS). The study region, the Arabian plate, is traditionally divided into the western Arabian shield and the eastern Arabian platform: The Arabian shield itself is a complicated mélange of crustal material, composed of several Proterozoic terrains separated by ophiolite-bearing suture zones and dotted by outcropping Cenozoic volcanic rocks (locally known as harrats). The Arabian platform is primarily covered by 8 to 10 km of Paleozoic, Mesozoic and Cenozoic sedimentary rocks. Our results reveal high Vp/Vs ratios in the region of Harrat Lunayyir, which are interpreted as solidified magma intrusions from old magmatic episodes in the shield. Our results also indicate slow velocities and large upper mantle lid temperatures below the southern and northern tips of the Arabian shield, when compared with the values obtained for the central shield. We argue that our inferred patterns of lid velocity and temperature are due to heating by thermal conduction from the Afar plume (and, possibly, the Jordan plume), and that volcanism in western Arabia may result from small-scale adiabatic ascent of magma diapirs.
CitationThe lithospheric shear-wave velocity structure of Saudi Arabia: Young volcanism in an old shield 2016 Tectonophysics
SponsorsWe are grateful to Mahmoud Salam, Wael Raddidi and the team at Saudi Geological Survey (SGS) for providing the broadband seismic data. We also thank Sung-Joon Chang and an anonymous reviewer for their constructive comments, which helped greatly in improving the manuscript. The research presented in the paper is supported by the cooperation between Saudi Geological Survey (SGS) and King Abdullah University of Science and Technology (KAUST).