Afro-Arabian plume

Afro-Arabian plume
Name	Afro-Arabian plume
Type	Mantle plume hypothesis
Region	East Africa, Arabian Peninsula, Red Sea
Age	Neogene–Quaternary
Associated features	East African Rift, Afar Triangle, Red Sea Rift, Gulf of Aden, Ethiopian Plateau

Afro-Arabian plume is a mantle upwelling proposed to connect heat and magmatism beneath the Ethiopian Plateau, the Afar Triangle, the Red Sea, and parts of the Arabian Peninsula and East Africa. The concept links large-scale volcanic provinces such as the Ethiopian Highlands, Djibouti rift volcanism, and the Danakil Depression to deep-seated mantle processes beneath the Horn of Africa and Arabia. Debate persists among workers from institutions like the United States Geological Survey, University of Oxford, Massachusetts Institute of Technology, and Swiss Federal Institute of Technology in Zurich about plume geometry, depth, and relation to plate-scale rifting.

Overview and Geological Setting

Proponents situate the plume beneath the intersection of the East African Rift, the Red Sea Rift, and the Gulf of Aden near the Afar Triple Junction, invoking analogues with the Iceland plume, the Hawaii hotspot, and the Réunion hotspot. Key surface expressions include the Ethiopian Plateau flood basalts, the Afar Depression silicic centers, and the Erta Ale volcanic system, which are studied alongside regional tectonic boundaries such as the Somali Plate and the Arabian Plate. Regional stratigraphy ties to events like the Oligocene flood basalt episodes and later Neogene to Quaternary rift-related volcanism identified in field campaigns by teams from the British Geological Survey and the Natural History Museum, London.

Tectonic Origin and Mantle Dynamics

Models propose either a single broad plume head, multiple plumelets, or lithospheric-control models championed by groups at the California Institute of Technology and the University of Cambridge. Seismic tomography from collaborations including the Incorporated Research Institutions for Seismology and the Institute of Geophysics, ETH Zurich shows low-velocity anomalies beneath the Ethiopian Plateau and the Arabian Shield, compared against global tomographic images of plumes under Yellowstone National Park and Iceland. Geodynamic modeling using approaches from researchers at the Princeton University and the Max Planck Institute for Chemistry tests thermal buoyancy, melt segregation, and plume–lithosphere interaction with influences from processes documented at the East Pacific Rise and the Mid-Atlantic Ridge.

Geochemical and Geophysical Evidence

Geochemical datasets from lava suites on the Ethiopian Plateau, Socotra Island, and the Asal Rift show isotopic affinities compared with mantle reservoirs characterized in studies of Ocean Island Basalts and mid-ocean ridge basalts. Trace-element signatures and helium isotopes measured by teams at Scripps Institution of Oceanography, Lamont–Doherty Earth Observatory, and the GFZ German Research Centre for Geosciences provide constraints on deep mantle components versus depleted mantle lithosphere seen in work on the Kerguelen Plateau and Seychelles microcontinent. Geophysical surveys—gravity, magnetics, and seismic arrays deployed by National Oceanography Centre, Southampton, USGS, and regional observatories—document crustal thinning, anomalous heat flow, and low-velocity zones akin to signals reported beneath Hawaii and Iceland.

Volcanism and Surface Expression

Surface volcanism ranges from flood basalt provinces like the Oligocene Ethiopian Traps to active basaltic systems such as Erta Ale and silicic complexes comparable to Yellowstone Caldera in terms of hotspot analogues. Rift propagation along the Red Sea Rift and the Gulf of Aden has produced aligned volcanic chains, volcanic fissures, and shield volcanoes observed in surveys by NASA satellites, airborne campaigns by National Aeronautics and Space Administration, and fieldwork from the University of Addis Ababa and Afar Research Project. Comparisons are drawn with volcanic provinces such as the Deccan Traps and the Columbia River Basalt Group to interpret eruption volumes, emplacement mechanisms, and interactions with crustal structures like the Horn of Africa lithosphere.

Chronology and Evolution

Chronological frameworks integrate radiometric ages from teams at Geological Survey of Ethiopia, University of Geneva, and University of Pisa with paleomagnetic stratigraphy correlated to global polarity timescales used by the International Commission on Stratigraphy. Timing links the Oligocene flood basalt event to Neogene rift initiation and Quaternary localized volcanism, mirroring evolutionary stages proposed for the Iceland plume and the Samoan hotspot. Evolving models accommodate episodic magmatism, plume channeling, and lithospheric delamination processes discussed in literature from Stanford University and the University of California, Berkeley.

Regional Impacts and Environmental Effects

The inferred plume has been invoked to explain uplift of the Ethiopian Plateau, drainage reorganizations affecting the Blue Nile, and paleoenvironmental changes during the Pliocene and Pleistocene that may have influenced hominin habitats studied by teams from the Max Planck Institute for Evolutionary Anthropology, National Museum of Ethiopia, and University College London. Large igneous province emplacement ties to global climate perturbations similar to those implicated for the Deccan Traps and mass-extinction proxies examined by researchers at the Smithsonian Institution and Carnegie Institution for Science. Ongoing multidisciplinary programs involving the African Union, regional geological surveys, and international universities continue to assess volcanohazard potential, geothermal resources, and crustal evolution across the Horn of Africa and Arabian Peninsula.

Category:Geology of Africa Category:Volcanism