Insights on the tectonic styles of the Red Sea rift using gravity and magnetic data

Abstract

Global topography, bathymetry, magnetic, and gravity data were analyzed to study the nature of the Red Sea crust to infer its tectonic regime. The Red Sea is a classic example of incipient ocean basin formation after the breakup of a continent. We used spectral analysis of the magnetic and gravity data and two-dimensional (2D) forward modelling of the gravity data to image crustal sources within the Red Sea. The magnetic data were also analyzed to determine the Curie point depth, which was then used to estimate heat flow values within the Red Sea. Profiles of bathymetry, gravity, magnetic, and heat flow data were constructed across the southern, central and northern portions of the Red Sea to determine crustal structural differences between these regions. Residual and regional gravity anomaly maps determined from the spectral analysis and 2D gravity forward models indicate that there is a large amplitude gravity maxima over the main axial trough within the central and southern Red Sea caused by a combination of partially molten material intruding into the crust and the formation of a new oceanic crust. However, the central portion of the Red Sea based on the residual gravity anomaly map is a transition zone where the oceanic crust is discontinuous and is separated by inter-trough zones. In the northern portion of the Red Sea, the discontinuous residual gravity maxima and high frequency magnetic anomalies can be correlated with isolated deeps implying the last stage of the continental rifting and beginning of seafloor spreading.