Here we report new major and trace element and Sr-Nd-Pb isotope data for Pleistocene basaltic lavas from the Fosdick Mountains, Ford Ranges in west Marie Byrd Land. The studied lavas erupted from three volcanic centers: Mt. Avers (basanites), Mt. Perkins (basalts) and Recess Nunatak (basanites). The lavas are geochemically homogeneous within each volcanic center, but vary in composition among the centers. Although the studied lavas have incompatible element enrichment patterns that are similar to other lavas from central and east Marie Byrd Land volcanoes, they have isotopic compositions that are not represented by other Marie Byrd Land volcanoes. This indicates that the mantle source regions feeding Marie Byrd Land volcanism are more heterogeneous than previously indicated. The geochemistry of these magmas provide a means to evaluate competing hypotheses for the origin of these magmas: plume-related, rift-related, or related to sinking of subducted slabs.