Partial melting of metapelites at ultrahigh-pressure conditions, Greenland Caledonides

Eclogite, orthogneiss and, by association, metapelite from an island at 78°N in North‐East Greenland experienced ultrahigh‐pressure (UHP) metamorphism at approximately 970 °C and 3.6 GPa, at the end of the Caledonian collision, 360–350 Ma. Hydrous metapelites contain abundant leucocratic layers and lenses composed of medium‐grained, anhedral, equigranular quartz, antiperthitic plagioclase and K‐feldspar with minor small garnet and kyanite crystals. Leucosomes are generally parallel to the matrix foliation, are interlayered with residual quartz bands, anastomose around residual garnet and commonly cross‐cut micaceous segregations. Textures suggest that the leucosomes crystallized from a syntectonic melt, but crystallized at the end of local high‐grade deformation. The metapelite outcrop is