A heterogeneous subcontinental mantle under the African-Arabian Plate boundary revealed by boron and radiogenic isotopes.

ABSTRACT: The northern and northwestern margins of the Arabian Plate are a locus of a diffuse and long-lasting (early Miocene to Pleistocene) Na-alkali basaltic volcanism, sourced in the asthenosphere mantle. The upwelling asthenosphere at the Africa-Arabia margin produces very limited magma volumes in the axial zone. Therefore, portions of hot, fertile mantle continue their eastward migration and are stored at shallower depths under the 100-km thick Arabian lithosphere, which is much thinner than the African one (≈175 km): this causes the occurrence and 20-Ma persistence of magma supply under the study area. Erupted basalts sampled a continuous variation of the mantle source, with a striking correlation among temperature, pressure and isotopic composition shifting between two end members: a 100 km-

SUBMITTER: Agostini S 

PROVIDER: S-EPMC8160130 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature