b)a)

c) d)

20

25

30

35

550500 600 650 700 750

800

Temperature (°C)

Pres

sure

(kba

r)

XMgGrossularPyrope

c

c

c b

b

a

a

20

25

30

35

550500 600 650 700 750 800

Temperature (°C)

Pres

sure

(kba

r)

c

c

c b

b

a

a

0.340.32

0.30

0.26

0.22

0.18

0.14

XMg

20

25

30

35

550500 600 650 700 750

800

Temperature (°C)

Pres

sure

(kba

r)

c

c

c b

b

a

a

0.210.180.14

0.10

0.06

0.24

0.24

0.21

Pyrope

c

c

c b

b

a

a

20

25

30

35

550500 600 650 700 750 800

Temperature (°C)

Pres

sure

(kba

r)Grossular

0.36

0.36

0.34

0.30

0.30

0.40

0.34

0.26

Appendix I. Eclogite D197 compositional isopleths for the calculated phase equilibria diagram. Labels a (core), b (mantle), and c (rim) in the figure correspond to the measured points shown in Figure 15a. Thick lines represent measured values. The grey star repre-sents the peak conditions shown in Figure 7b. (a) Grossular content. (b) Pyrope content. (c) XMg. Predicted XMg values do not correspond to the measured values. (d) Intersec-tion between garnet grossular and pyrope isopleths.