A Geophysical Study of the Red Sea Axial Trough between 20*5 and 22 N

Abstract

Summary New bathymetric, seismic reflexion, gravity and magnetic data have been obtained in a detailed survey of part of the axial trough in the central Red Sea. These data show that the trough is not continuous, but is broken into two sections separated by a shallow region, called the ‘inter-trough zone’. This zone has a thick sediment cover and is devoid of magnetic anomalies. It may represent a fracture zone into which salt and other sediments have flowed, or it may be a section of spreading axis which has remained covered with sediments for an unknown reason. The transverse magnetic anomalies, previously recognized by Allan, Phillips and other, have been fully mapped, and a further transverse lineation has been discovered. Using three-dimensional computations, a model has been developed which can account for these lineations as the magnetic end effects of a series of short spreading axes offset by closely-spaced transform faults. The development of such a configuration is discussed and can be seen as a natural consequence of the plate geometry in this region.