Evidence of hotspot paths below Arabia and the Horn of Africa and consequences on the Red Sea opening

Two-step closure of the Miocene Indian Ocean Gateway to the Mediterranean

“…The alkaline volcanism that produced these source rocks is characterised by highly radiogenic ɛNd values between −5 and +5 52–54 . The Afar hotspot volcanism and the associated plume may have been established prior to the Eocene 55,56 , but it is unclear if any drainage system supplying weathering products from these volcanic rocks to the Mediterranean existed before the late Miocene 57 . The Aegean and western Anatolian volcanism had already been initiated during the Miocene 58,59 , yet it was still nascent at that time (with continued development until the present).…”

The Evolution of Mantle Plumes in East Africa

“…The mixing of the Ethiopia plume with the Afar plume further highlights why global tomography models can hardly distinguish the two plumes. In conclusion, the Afar plume has risen with an origin ~600 km east of the Ethiopia plume at the CMB (Vicente de Gouveia et al, 2018), and it may have become a dying plume because its plume tail was disconnected from the CMB by the interaction between the westward migrating Tethyan slab and the African LLSVP as discussed in section 5. The chronology of the Ethiopia and the Afar plumes is also compatible with the observation of the highest temperatures from old and recent basalts in roughly the same place in the Ethiopian plateau discussed in section 2.…”

“…Yellow ellipses indicate locations of low‐velocity anomalies other than those corresponding to the Afar and the Kenya plumes observed in other regional tomography models (Bastow et al, 2008; Civiero et al, 2015, 2016). White triangles represent the position of “the East Africa plume” suggested by Vicente de Gouveia et al (2018).…”

“…The Afar plume is now detached from the African LLSVP possibly due to the interaction with the subducted Tethyan slab, and as a consequence, it is dying out. However, as paleomagnetic reconstructions show that the current Afar plume cannot be responsible for the Ethiopia‐Yemen traps formed ~30 Ma, the traps must have been created by a third “Ethiopia” plume (Vicente de Gouveia et al, 2018) that has been subsequently getting mixed with the Afar plume. This time‐dependent three‐plume scenario explains well the geochemical observations of no hotspot track of the Afar plume unlike its counterpart in the Kenyan plateau and a third low‐velocity anomaly in the upper mantle between the Afar and the Kenya plumes in recent regional tomography models (Celli et al, 2020; Emry et al, 2019).…”

Plume Versus Slab-Pull: Example from the Arabian Plate

“…There is still uncertainty about whether the RS and the GOA formed as a whole-sale tearing of the continental crust or as an episodic or diachronic extension (e.g., Almalki et al, 2016;Nonn et al, 2019). Various models have been proposed for the opening of the RS and the GOA including asymmetric, symmetrical extension and pull-apart models (e.g., Sultan et al, 1992;d'Acremont et al, 2005). The mechanism of opening may involve intrusive magmatic activity as a major role in thinning the continental lithosphere prior to the inception of spreading [e.g., Bohannon and Eittreim, (1991)), a mechanical stretching of the lithosphere (e.g., Martinez and Cochran, (1988)], or simply a localization of the ocean crust formation (e.g., Makris and Rihm, 1991).…”