Giant Quasi-Ring Mantle Structure in the African–Arabian Junction: Results Derived from the Geological–Geophysical Data Integration

Abstract

The tectonic–geodynamic characteristics of the North African–Arabian region are complicated by the interaction of numerous factors. To study this interaction, we primarily used satellite gravimetric data (retracked to the Earth’s surface), which has been acknowledged as a powerful tool for tectonic–geodynamic zoning. The applied polynomial averaging of gravity data indicated the presence of a giant, deep quasi-ring structure in the Eastern Mediterranean, the center of which is located under the island of Cyprus. Simultaneously, the geometrical center of the revealed structure coincides with the Earth’s critical latitude of 35°. A quantitative analysis of the obtained gravitational anomaly made it possible to estimate the depth of the upper edge of the anomalous body as 1650‒1700 km. The GPS vector map coinciding with the gravitational trend indicates counterclockwise rotation of this structure. A review of paleomagnetic data on the projection of the discovered structure into the Earth’s surface also confirms its counterclockwise rotation. Analysis of the geoid anomalies map and seismic tomography data commonly prove the presence of this deep anomaly. The structural and geodynamic characteristics of the region and paleobiogeographic data are consistent with the proposed physical–geological model. Comprehensive analysis of petrological, mineralogical, and tectonic data suggests a relationship between the discovered deep structure and near-surface processes. The deep structure also sheds light on specific anomalous effects in the upper layer of the crust, including the high-intensity Cyprus gravitational anomaly, counterclockwise rotation of the Mesozoic terrane belt, configuration of the Sinai Plate, and asymmetry of sedimentary basins along continental faults.