The statistical analysis of the compositions of glasses from the spreading ridges surrounding Antarctica showed that the process of oceanic crust accretion on them was related mainly to the generation and fractionation of initial melts (TOR-2 type) typical of all oceanic spreading zones except for the North Atlantic. Deeper melts (TOR-1) occur in the areas with a hotter lithosphere near Bouvet Island. In contrast, sodium-enriched tholeiites generated in shallow levels (Na-TOR) are related to the areas of relatively cold oceanic lithosphere, i.e., boundary zones between large tectonic provinces of spreading zones, which have their own evolutionary history. A comparison of isotopic signatures of the enriched tholeiites of the ridges demonstrated that their formation was connected with the melting of a source, which could be represented either by altered subcontinental mantle or continental crust.