『Abstract
　Direct measurements of calcite (1014)（後の1の頭に-） faces were performed using in situ atomic force microscopy (AFM) to reveal the dissolution processes as a function of solution saturation state and temperature. Time-sequential AFM images demonstrated that step velocities at constant temperature increased with increasing undersaturation. The anisotropy of obtuse and acute step velocities appeared to become more significant as solutions approached equilibrium and temperature increased. At saturation state Ω＞0.02, a curvilinear boundary was formed at the intersection of two acute steps and the initially rhombohedral etch pit exhibited a nearly triangular shape. This suggests that the [441（最初の4の頭に-）]a and [481（1の頭に-）]a steps may not belong to the calcite-aqueous solution equilibrium system. Further increase in the saturation state (Ω≧0.3) led to a lack of each pit formation and dissolution primarily occurred at existing steps, in accordance with Teng (2004). Analysis of step kinetics at different temperatures yielded activation energies of 25±6 kJ/mol and 14± 13 kJ/mol for obtuse and acute steps, respectively. The inconsistencies in etch pit morphology, step anisotropy, and step activation energies from the present study with those of studies far-from-equilibrium can be explained by increased influence of the backward reaction, or growth, near-equilibrium. We propose that the backward reaction occurs preferentially at the acute-acute kink sites. The kinetics and effective activation energies of near-equilibrium calcite dissolution presented in this work provide accurate experimental data under likely CO2 sequestration conditions, and thus are crucial to the development of robust geochemical models that predict the long-term performance of mineral-trapped CO2.』

1. Introduction
2. Experimental
　2.1. Sample and solution preparation
　2.2. AFM apparatus
3. Results and discussion
　3.1. Etch pit formation and morphology
　3.2. Step kinetics
　3.3. Activation energy
4. Conclusion
Acknowledgments
References