Trace element concentrations in plagioclase from Petit St. Vincent lava and xenoliths plotted against Sr: (a) La, (b) Ba, (c) Li and (d) Cu (one plagioclase phenocryst from lava contains 80-ppm Cu). Igneous xenoliths shown as orange symbols with Sr-rich plagioclases from PSV20 highlighted in red; meta-igneous xenolith in blue open symbols; phenocrysts from lava in black. Insets in (a) and (b) show whole-rock variation for C-series ‘ankaramites’ (red) and M-series ‘picrites’ (grey) from Grenada (Thirlwall et al., 1996; White et al., 2017), as well as Petit St. Vincent lavas. Corresponding differentiation trends are superimposed on the plagioclase data in (a). Cores and rims for some phenocryst and xenolith plagioclases are illustrated on (a). Note that plagioclase from PSV8 differs from plagioclase from other meta-igneous samples, resembling more closely igneous plagioclases.