ABSTRACT
Associating lithospheric suture zones of the Arabian-Nubian Shield on either side of the central Red Sea is important for constraining Arabia-Nubia plate motion and potentially testing plate rigidity during continental break-up. However, that association is difficult because of the non-unique character of the shield suture zones, some shield areas are obscured by later volcanics and sediments, and because some intervening shield crust that was extended during continental rifting now lies submerged beneath thick Miocene evaporites in the Red Sea and is thus obscured. Here, we show that an association is clearly favoured if shield structures are interpreted along with an oceanic segmentation revealed by the satellite-derived gravity field. The Proterozoic subduction suture zones associated include the Bi’r Umq on the Arabian shield with a previously unrecognised suture zone in the Nubian Shield (herein called Shagara), Fatma with Nakaseib and Ad Damm with Ashat suture zone. Bouguer gravity anomaly lows, produced by oceanic spreading discontinuities of the new mid-ocean ridge formed in the Red Sea, connect two sets of suture zones: Bi’r Umq-Shagara and Fatma-Nakaseib. As far as we are aware, these are the first short-offset oceanic discontinuities to be clearly linked to adjacent shield structures.
