Table 1 Hydrous minerals, dense hydrous magnesium silicates (DHMSs), and nominally anhydrous minerals (NAMs) which could potentially exist in subducting oceanic plates Schmidt and Poli (1998); Inoue (2000); Ono (1998); Ohtani et al. (2001b). All Mg atoms can be replaced with Fe atoms in the chemical formula shown below

Hydrous peridotite

Lizardite

Liz

Mg\(_3\)Si\(_2\)O\(_5\)(OH)\(_4\)

Antigorite

Atg

Mg\(_{3m-3}\)Si\(_{2m}\)O\(_{5m}\)(OH)\(_{4m-6}\)

(m=13\(\sim\)24)

Chlorite

Chl

Mg\(_{12}\)(Si,Al)\(_8\)O\(_{20}\)(OH)\(_{16}\)

Talc

Tlc

Mg\(_{3}\)Si\(_4\)O\(_{10}\)(OH)\(_{2}\)

Phase A

A

Mg\(_7\)Si\(_2\)O\(_{8}\)(OH)\(_6\)

Phase B

B

Mg\(_{12}\)Si\(_4\)O\(_{19}\)(OH)\(_2\)

Phase E

E

Mg\(_{2.3}\)Si\(_{1.25}\)O\(_6\)H\(_{2.4}\)

Superhydrous phase B (=Phase C)

SuB

Mg\(_{10}\)Si\(_3\)O\(_{18}\)H\(_4\)

Phase D (=Phase F=Phase G)

D

MgSi\(_2\)O\(_6\)H\(_2\)

Phase H

H

MgSiO\(_4\)H\(_2\)

Hydrous wadsleyite

\(\beta\)

Mg\(_2\)SiO\(_4\) (H\(_2\)O<3.3 wt%)

Hydrous ringwoodite

\(\gamma\)

Mg\(_2\)SiO\(_4\) (H\(_2\)O<2.7 wt%)

Hydrous MORB

Amphibole

Amp

Ca\(_2\)Mg\(_3\)Al\(_2\)Si\(_6\)Al\(_2\)O\(_{22}\)(OH)\(_2\)

Lawsonite

Law

CaAl\(_2\)Si\(_2\)O\(_7\)(OH)\(_2 \cdot\)H\(_2\)O

Sediment

Phengite

Phe

K(Al,Mg)\(_2\)(OH)\(_2\)(SiAl)\(_4\)O\(_{10}\)

Topaz-OH

–

Al\(_2\)SiO\(_4\)(OH)\(_2\)

Phase Egg

Egg

AlSiO\(_3\)OH

\(\delta\)-AlOOH

–

AlOOH

Pyrite-type AlOOH/\(\gamma\)-AlOOH

AlOOH

Goethite (\(\alpha\)-FeOOH)

Goe

FeOOH

\(\epsilon\)-FeOOH

–

FeOOH

Pyrite-type FeOOH\(_x\)

–

FeO\(_2\)H\(_x\), x=0.39-1

HH phase

–

(Fe,Al)O\(_2\)H\(_x\) (x\(\sim\)1?)