Oblique rifting and segmentation of the NE Gulf of Aden passive margin

摘要: [1] The Gulf of Aden is a young, obliquely opening, oceanic basin where tectonic structures can easily be followed and correlated from the passive margins to active mid-oceanic ridge. It an ideal laboratory for studies continental lithosphere breakup rifting spreading. The northeastern margin offers opportunity study on land deformation associated with oblique over wide area encompassing two segments margin, either side Socotra fracture zone, exhibiting distinct morphologic, stratigraphic, structural features. western segment characterized by elevated rift shoulder large grabens filled thick synrift series, whereas eastern exhibits low elevation devoid major extensional typical deposits. Though morphostructural features are different, stress field analysis provides coherent results all along margin. Four directions extension have been recognized considered representative tensional fields permutations horizontal principal stresses σ2 σ3. dominant extension, N150°E N20°E, perpendicular mean trend (N75°E) parallel its opening direction (N20°E–N30°E), respectively. Unlike another in part gulf, our data suggest that stage older than N20°E stage. These conflicting chronologies, which nowhere unambiguously established, extensions coexisted during rifting. On-land compared offshore interpreted reference segmentation represents local accommodation homogeneous regional field, reveals asymmetry process. first-order Sheba Ridge inherited prior