“…Studies of plagioclase megacrysts in MORB have noted a wide range of textures (Kuo & Kirkpatrick, 1982;Winpenny & Maclennan, 2014), major element zonation (Cordier et al, 2007;Hellevang & Pedersen, 2008;Kuo & Kirkpatrick, 1982), trace element zonation (Adams et al, 2011;Zellmer et al, 2010), and isotopic heterogeneities (Bryce & DePaolo, 2004;Halldorsson et al, 2008;Lange et al, 2013;Winpenny & Maclennan, 2014). Evidence from phenocrysts as well as MIs has documented that the megacrysts are usually, but not always, more anorthitic than those in equilibrium with their host lavas (Cullen et al, 1989;Davis & Clague, 1987;Hellevang & Pedersen, 2008;Natland, 1989;Stakes & Franklin, 1994), demonstrating the ability of plagioclase to record earlier stages of melt evolution.…”