The Sedimentary Evolution of the Red Sea and Gulf of Aden

Abstract

Onset of rifting, andflooding by marine waters, occurred in the late Oligocene in the G u y of Aden and southern Red Sea. The northern part o f t h e Red Sea may have been a largely continental rift at this initial stage, but continued rifting established marine conditions throughout the system by the early Miocene. Episodic isolation of the Red Sea system, leading to evaporite deposition in some basins, commenced in the mid-Miocene and over two kilometres of salt had accumulated in most Red Sea basins by the end ofthe Miocene.Re-esta blish men t of persistentlym arin e conditions occurred in the Pliocene, and m arin e recharge is now sufficiently high to permit vigorous carbonate build-ups in shallow-water areas.elastic sediment textures suggest that marginal escarpments, which jirst developed during the onset ofrifting, were strongly uplifted in the Pliocene-to-Recent period. Subsidence of basin floors seems to have been particularly rapid during the period dominated by salt deposition. I f eruption of sea-floor basalts in the axial r$ areas is excluded, volumetrically important volcanism is centred on the present Afar triangle area, and is confined to the Oligocene and early Miocene. The amount of contemporary volcanic dkbris in the sandstones is consequently not particularly high. Some sandstones in northern Ethiopia, Sudan and Egypt do contain abundant acidic volcanic clasts, but these are derived from the Proterozoic basement and cause less diagenetic reservoir damage than contemporary glassy volcanic ash.Sandstones deposited in freely-drained alluvial fan settings are characterised by early diagenetic kaolinite, whereas those of sabkha and marginal-marine settings tend to show relatively early diagenetic chlorite. Those alluvial fan sandstones which were subsequently invaded by reduced pore waters espelled~from the basin axis, and those in the basin axis, ojen developed later diagmetic chlorite.

Madbi-Biyadh/Qishn (!) petroleum system in the onshore Masila Basin of the Eastern Yemen

“…14). These traps were developed and reactivated during OligoceneeMiddle Miocene time as resulting of opening the Red Sea and the Gulf of Aden in the Tertiary rifting tectonic event (Hatitham and Nani, 1990;Bott et al, 1992;Crossley et al, 1992;Huchon et al, 1991;Redfern and Jones, 1995). This tectonic event caused deformation of the pre-Oligocene formed traps and led to the formation of newly formed traps of the structural, stratigraphic and combination types (Fig.…”

Elevated, passive continental margins: Not rift shoulders, but expressions of episodic, post-rift burial and exhumation

“…Episodic isolation in the mid-Miocene led to evaporite deposition in some basins, but marine conditions were re-established in the Pliocene with carbonate build-ups in shallow-water areas. Crossley et al (1992) interpreted clastic sediment textures to indicate that marginal escarpments, which first developed during the onset of rifting, were strongly uplifted in the Pliocene-to-Recent period. Daradich et al (2003) also presented evidence that the uplift along the Red Sea-and in particular the tilting of the 1000 km wide Arabian plate-is a young feature (since 12 Ma).…”

“…Onset of rifting and flooding by marine waters occurred in the late Oligocene in the southern Red Sea (Crossley et al, 1992), but continued rifting established marine conditions throughout the system by the early Miocene. Episodic isolation in the mid-Miocene led to evaporite deposition in some basins, but marine conditions were re-established in the Pliocene with carbonate build-ups in shallow-water areas.…”

Petrophysical analysis of early cretaceous Saar carbonates from Sharyoof oilfield in the Masila Basin, eastern Yemen, and their impact on reservoir properties and quality

“…2). These structures were formed during late Jurassicearly Cretaceous and developed during Oligocene-Middle Miocene time as a result of opening of the Red Sea and the Gulf of Aden during the Tertiary rifting tectonic event (Haitham and Nani 1990;Bott et al 1992;Crossley et al 1992;Huchon et al 1991;Redfern and Jones 1995). The Sharyoof oilfield contains sedimentary rocks ranging from Jurassic to Tertiary in age, including Saar Formation (Fig.…”