Figure 2

P–T pseudosection for a metamorphosed andesite, displaying the metamorphic facies for this protolith and the PT boundaries of key minerals (inset). Different shading intensity of the fields represents changes in variance of the phase assemblage. Warm and cool slab-parallel geotherms are displayed for reference (red dashed lines). Isopycnals for the metamorphosed andesite are displayed in dashed black lines with the labelled boxes representing the P–T conditions inferred for natural eclogite terranes (Table S2). No red shading is present as all phase assemblages density remain less than the ambient mantle.