Data for: Chemical nature of hydrothermal fluids generated by serpentinization and carbonation of komatiite: Implications for H2-rich hydrothermal system and ocean chemistry in the early Earth

Dataset of hydrothermal experiments simulating oceanic hydrothermal systems. Table 1: Main composition of run products after experiment (wt.%) in Exp-100 and Exp-300 the synthetic komatiite, mineral/glass phases therein, starting materials. Table 2: Composition of the sampled fluids in the experiments (mmol/kg). Table 3:Measured chemical compositions of hydrothermal fluids in natural hydrothermal systems and hot spring. Table 4: H2 flux estimation in modern and early Earth.