Trace element abundances in clinopyroxene (cpx) from cumulate xenoliths are used to characterize the nature of primitive magma-forming processes beneath the Aleutian island arc. Clinopyroxenes from deformed mafic and ultramafic xenoliths hosted in a Neogene-age mafic sill from Kanaga Island have widely varying trace element abundances (Sr=8–32, Y=2–64, Zr=2–38, Nd=0.65–16 ppm) that are generall...

We present major and trace element concentrations in conjunction with Sr–Nd isotope ratios to investigate the geochemical characteristics of mélange formation along the subduction zone slab–mantle interface. Mélange matrix of the Catalina Schist formed within an active subduction zone of the southern California borderland in Cretaceous time. Mélange formed through the synergistic effects of def...

Abstract Intraplate basaltic volcanism commonly exhibits wide compositional ranges from silica-undersaturated alkaline basalts to silica-saturated tholeiitic basalts. Possible mechanisms for the transition involve variable degrees of partial melting a same source, decompression at different mantle depths (so-called ‘lid effect’), and melt-peridotite interaction. To discriminate between these me...