Fig. 9: Mineral assemblage and H2O content evolution in crustal rocks during subduction.
From: Deep crustal deformation driven by reaction-induced weakening
Thermodynamic modeling for two average compositions of subducted metasediments from the Alps90 (left panel) and mid-ocean ridge basalts91 (right panel) showing the major mineral reaction boundaries and the evolution of structurally-bound H2O content (in wt.%) as a function of P and T. See “Methods” for details. The results are compared with a compilation of peak P–T estimates of subducted oceanic units from the Alps70. Note the switch in predominant lithology at the blueschist–eclogite facies transition between sediment–dominated and mafic–dominated units. Metamorphic facies are indicated in purple using the following abbreviations: EC: eclogite, BS: blueschist, GS: greenschist, Amp: amphibolite, PP: prehnite–pumpellyite. Mineral abbreviations: Law: lawsonite, Ctd: Chloritoid, Bi: biotite, Ep: epidote, Gln: glaucophane, Chl: chlorite.
