『Abstract
　Dissolution rates of diopside, forsterite (Fo100 and Fo92), wollastonite, and hornblende were measured at 25℃ in NaCl solutions as a function of pH (1≦pH≦12), p CO2 (0 and 1 atm) and activity of HCO3^- and CO3^2-(10^-5≦ΣCO2 ≦0.1 M). Dissolution rates of diopside, forsterite, and hornblende are not affected, within the experimental uncertainty, by 1 atm p CO2 at pH〜4 and by the presence of bicarbonate (up to 0.1 M) and carbonate (up to 0.01 M) ions at pH of 8 and 11-12, respectively. Although wollastonite dissolution rates are unaffected by p CO2 at pH〜4, its rates are increased by the presence of HCO3^- at 0.01≦[HCO3^-]≦0.1 M and pH = 7-8 and decreased slightly by CO3^2- at [CO3^2-]＞0.0001 M and pH〜12. These results should be useful for modeling the effect of silicate rock weathering on the global biogeochemical cycle of carbon. For the first time, we were able to distinguish the net effect of p CO2 versus that of pH. It is observed, in general accord with previous results, that the direct effect of CO2 on basic silicates dissolution rates is very weak. As a result, the major parameter governing basic silicates dissolution is pH of soil solutions in contact with minerals.

Keywords: Kinetics; Dissolution; Diopside; Forsterite; Wollastonite; Hornblende; Dissolved CO2 』

1. Introduction
2. Materials and methods
3. Results and discussion
　3.1. Dissolution rates as a function of pH
　3.2. Dissolution rates as a function of p CO2 and HCO3^- and CO3^2- concentration
4. Discussion
　4.1. Comparison with previous results
　4.2. Consequences for modeling chemical weathering at the earth surface
Acknowledgements
References