Figure 2
From: Continuous eclogite melting and variable refertilisation in upwelling heterogeneous mantle
Ca-eskolaite component in experimentally crystallised clinopyroxene from Res2 and GA2 as a function of pressure and temperature.
The symbol ‘+’ indicates the presence of quartz/coesite as residual phase. At a given pressure, both below and above quartz/coesite out, Ca-eskolaite first increases and then decreases with increasing temperature. Although melting residues of Res2 lose siliceous melt fractions and become increasingly depleted in Ca-eskolaite, they still retain their SiO2–saturated character (as will their resulting melt fractions) and are not exhausted in Ca-eskolaite during continuous melt extraction on adiabatic ascent (this Fig., SFig. 6; STable 3). Thus, in contrast to previous predictions20, melting residues of initial coesite/quartz-bearing or bimineralic eclogite with Ca-Eskolaite component in clinopyroxene present never become SiO2-deficient (in terms of high pressure normative components) along adiabatic paths and remain on the SiO2-excess side of the thermal divide in SFig. 6.
