Petrogenesis of Cretaceous mafic intrusive rocks, Fosdick Mountains, West Antarctica: Melting of the sub-continental arc mantle along the Gondwana margin

► A diorite pluton and widely distributed mafic dykes occur in the Fosdick Mountains. ► The mafic intrusive rocks have Cretaceous crystallization ages ranging from ca 113 to 97 Ma. ► They are medium- to high-K-series calc-alkaline rocks with basic-intermediate composition. ► The trace element and Sr-Nd isotope data suggest melting of metasomatized sub-arc mantle sources.