Reactions between komatiite and CO2-rich seawater at 250 and 350 °C, 500 bars: implications for hydrogen generation in the Hadean seafloor hydrothermal system

Progress in Earth and Planetary Science

Table 1 Compositions of the synthetic komatiite, mineral/glass phases therein, starting materials used in a previous experiment (wt.%)

Sample	Al-depleted komatiite	Olivine	Glass	Spinel	Basalt^b
SiO₂	46.29	41.02	50.74	0.22	49.84
TiO	0.37	0.00	0.68	0.22	0.73
Al₂O₃	4.30	0.20	7.74	6.43	15.82
Cr₂O₃	0.21	0.48	0.52	52.22	–
FeO_total ^a	12.52	9.70	14.81	22.03	11.00
MnO	0.13	0.09	0.18	0.14	0.22
MgO	27.47	48.80	12.57	15.49	9.44
CaO	7.20	0.30	11.84	0.22	10.84
Na₂O	0.06	0.00	0.23	0.00	1.88
K₂O	0.02	0.02	0.05	0.02	0.18
NiO	0.11	0.34	0.01	0.22	–
Total	98.68	100.95	99.37	97.23	99.95
Mg^#c	79.64	89.96	60.21	55.62	60.47