The Gulf of Aden: Structure and evolution of a young ocean basin and continental margin

摘要: New marine geophysical data are used to describe the structure and history of Gulf Aden. Magnetic anomaly shows seafloor spreading magnetic anomalies Sheba Ridge from axial 5 (10 m.y. B.P.) between Owen fracture zone 45 /sup 0/E 2' (3 or 3 (4 west 0/E. The does not support two episodes recently proposed. Landward is a quiet uncorrelatable anomalies. boundary also structural effectively marking edge Ridge, with deeper basement lacking significant topographic gradient found on landward side. A only where splits continental lithosphere but East ridge old oceanic lithosphre Somali basins. There position occupied by margin within gulf marked nonmagnetic complexes that stretch continents zone. an isochron in either Aden ormore » Red Sea, suggesting horizontal motions can occur prior initiation spreading. offset Dead Sea Rift estimate 80 160 km opening, amounting 65% 200% extension initial rift valley, occurred establishment mid-ocean ridge. It suggested development new ocean basin occurs stages. first involves diffuse over area perhaps 10 wide valley environment without organized center. This followed concentration at single axis beginning true spreading.« less