『Abstract
　In situ Atomic Force Microscopy, AFM, experiments have been carried out using calcite cleavage surfaces in contact with solutions of MgSO4, MgCl2, Na2SO4 and NaCl in order to attempt to understand the role of Mg²⁺ during calcite dissolution. Although previous work has indicated that magnesium inhibits calcite dissolution, quantitative AFM analyses show that despite the fact Mg²⁺ inhibits etch pit spreading, it increases the density and depth of etch pits nucleated on calcite surfaces and, subsequently, the overall dissolution rates:i.e., from 10^-11.75 mol cm^-2 s^-1 (in deionized water) up to 10^-10.54 mol cm^-2 s^-1 (in 2.8 M MgSO4). Such an effect is concentration-dependent and it is most evident in concentrated solutions ([Mg²⁺] >> 50 mM). These results show that common soluble salts (especially Mg sulfates) may play a critical role in the chemical weathering of carbonate rocks in nature as well as in the decay of carbonate stone in buildings and statuary.』

1. Introduction
2. Experimental
3. Results
　3.1. General features of etch pits
　3.2. Etch pit spreading rats
　3.3. Etch pit deepening rates
　3.4. Dissolution rates
　3.5. Crystallite size
　3.6. ESEM-EDS analysis
4. Discussion
　4.1. Effect of Mg²⁺ on calcite dissolution rates: etch pit spreading vs. deepening rates and etch pit density
　4.2. Etch pit nucleation: the possible role of Mg²⁺ adsorption
　4.3. Magnesium incorporation at <441（最初の4の頭に-）>+ steps
　4.4. The role of SO4^2- in magnesium-induced calcite dissolution
　4.5. The role of Na⁺ in calcite dissolution
5. Conclusions
Acknowledgments
References