| Autor: |
Petrunin, A. G., Kaban, M. K., El Khrepy, S., Al‐Arifi, N. |
| Zdroj: |
Tectonics; Feb2020, Vol. 39 Issue 2, p1-11, 11p |
| Abstrakt: |
We present a new model of the stress state and present‐day tectonics of the Red Sea Rift (RSR) based on an instantaneous geodynamic mantle flow model. The initial density and viscosity variations in the mantle are derived from a joint inversion of gravity, residual topography, and tomography, which provides higher resolution than existing models. The calculated mantle flow shows clear distinctions along the rift axis. The tectonics of the southern part of the Red Sea is mainly controlled by the Afar plume and characterized by divergent mantle flow. The passive rifting along the central part of the RSR can be explained either by asthenospheric upwelling due to the Red Sea floor spreading or by the plume, rising from the transition zone and not directly related to the Afar plume. We also observed ridge‐axis‐aligned flow in the uppermost mantle in the northern part of the RSR. Plain Language Summary: The Red Sea region is a highly populated area that is characterized by very active tectonics, which is responsible for earthquakes and geothermal activity. Mantle convection is one of the main driving forces that control plate tectonics at all levels. Therefore, modeling of the mantle convection can aid in understanding the origin and development of the tectonic processes in the region. The main difficulty in such modeling in the Middle East is that there exists a strong interplay of regional and global factors. To date, dynamic models for this region were based on low‐resolution global models. We present a novel dynamic model, which includes high‐resolution density and viscosity distributions as well as weak plate boundaries, which are embedded in the global convection model. Mantle flow velocities and principal stress directions were thus estimated for the lithosphere and upper mantle in the region. The resulting mantle flow patterns show a clear distinction in tectonics of three different parts of the Red Sea Valley. Furthermore, the stress orientations explain the fault structures in the Red Sea Basin. Key Points: The Afar plume acts only in the southern part of the Red Sea Rift forming two flow branches in the northern and nearly eastern directionsThe central part of the Red Sea Rift is a passive rift not directly related to the Afar plumeThe modeled stress field shows an off‐axis extension with a strike‐slip component along all segments of the Red Sea Rift [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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