Blueschist facies metabasites from the Emo Metamorphics of Papua New Guinea contain the assemblage quartz-albite-phengite-stilpnomelane-ferroglaucophane-chlorite-almandine-epidote-sphene-apatite + relict igneous pyroxene with omphacitic rims. The assemblage is similar to the lawsonite-epidote transition zone on New Caledonia. Textural variation from unfoliated to foliated blueschist is marked by an increase in retrograde modal actinolite and chlorite, suggesting that strain has accelerated the actinolite- and chlorite-forming reaction. Application of standard geobarometers and geothermometers to the primary assemblage suggests pressure and temperature conditions of metamorphism of approximately 7.0 kbar and 320°C. The textural variation suggests that the Emo Metamorphics may be a sliver of oceanic crust caught up in the thrusting that accompanied obduction of the Papuan ophiolite. The resulting depressurization led to retrograde growth of actinolite and chlorite.