The geochemical characteristics of the Jurassic plume magmatism within Ahlmannryggen massif (Queen Maud Land, East Antarctica)

Mesozoic dikes associated with the Karoo plume were studied within the East Antarctica where at Queen Maud Land on the Almannryggen massif high-Ti magnesian Fe-basalts were found. It is assumed that such basalts originate by means of the pyroxenite-containing mantle melting. The isotopic characteristics of the studied dolerites reflect the composition of the pyroxenite source - the ancient oceanic lithosphere (ЕМI), submerged at the mantle depths of 150-170 km in the paleosubduction zone of the Gondwanian continent and transformed 180 m.y. ago into the pyroxenite melt when interacting with the plume mantle peridotite.