Progress in Earth and Planetary Science

Table 3 Composition of run products (wt.%)

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

Experiment-250 °C								Experiment-350 °C
Sample	Serp or Sme/Chl mixture^b			Dolomite			Siderite	Serp or Sme/Chl mixture^b			Calcite			Olivine^c	Magnetite
SiO₂	41.37	40.89	33.38	0.00	0.00	0.00	3.80	38.55	35.52	38.87	0.00	0.00	0.00	41.60	2.76
TiO	0.44	0.43	0.64	0.01	0.05	0.15	2.96	0.52	0.47	0.17	0.00	0.00	0.00	0.01	0.18
Al₂O₃	7.00	6.88	11.56	0.06	0.00	0.01	0.13	6.82	6.84	6.38	0.07	0.00	0.01	0.06	0.02
Cr₂O₃	0.47	0.43	0.29	0.11	0.06	0.12	1.46	0.37	0.47	0.39	0.04	0.00	0.02	0.14	0.23
FeO_total ^a	13.32	13.65	15.55	3.22	6.66	9.05	39.55	16.84	16.51	13.77	0.18	0.37	0.77	5.33	85.06
MnO	0.16	0.14	0.18	0.53	0.49	0.49	0.12	0.19	0.34	0.20	0.13	0.36	0.72	0.05	0.40
MgO	24.05	23.48	24.10	17.69	17.39	17.43	1.32	23.13	25.21	25.98	0.17	0.74	0.79	51.46	0.36
CaO	0.83	0.81	0.17	26.01	29.47	23.75	0.26	0.28	0.13	0.46	56.29	54.95	58.68	0.32	0.29
Na₂O	0.06	0.08	0.03	0.03	0.11	0.04	0.09	0.16	0.07	0.15	0.01	0.00	0.00	0.00	0.02
K₂O	0.09	0.11	0.02	0.03	0.02	0.02	0.05	0.04	0.01	0.03	0.01	0.01	0.01	0.02	0.03
NiO	0.17	0.20	0.12	0.00	0.00	0.08	0.10	0.10	0.00	0.16	0.01	0.00	0.05	0.45	0.10
Total	87.96	87.10	86.05	47.67	54.25	51.13	49.84	86.98	85.59	86.56	56.91	56.43	61.04	99.43	89.45
Mg# ^d	76.30	75.40	73.43	90.73	82.31	77.43	5.63	71.00	73.13	77.08	61.52	78.23	64.50	94.51	0.74

^aTotal iron as FeO
^bSerpentine or smectite/chlorite mixture
^cAlterlation or relict olivine
^dMg# = [Mg / (Mg+Fe)] × 100

Back to article page