『Abstract
　In-situ measurement of anorthite dissolution in Na-Cl-OH solutions at an ionic strength (IS) of 0.5 mol/L (M) and in artificial seawater (IS=0.7M) were conducted at 22℃ using white-light, phase-shift interference microscopy (PSI-M). Nanometer-scale surface topography by PSI-M revealed three-dimensionally inhomogeneous surface dissolution, which is commonly observed as retreating steps on anorthite surfaces. Continuous dissolution of the anorthite cleavage surface (010) was successfully measured within a day. The vertical dissolution velocity was 4.3×10^-5 to 1.4×10^-3 nm/s. The obtained dissolution rates showed a typical dependency on pH with a reaction order of 0.191, and could be consistently extended to the previous data obtained under acidic conditions (Luttge et al. 1999). In-homogeneities in the vertical dissolution velocities at each pH condition could be interpreted by the step dynamics explained by the Burton-Cablera-Frank (BCF) theory (Burton et al. 1951). These results emphasize that the velocity of step retreat is a strong function of the step density, whichhas to be taken into account when describing the global dissolution phenomena on mineral surfaces.

Keywords: Interferometry; dissolution; anorthite; step dynamics』

Introduction
　Optical method
　Reference for PSI measurement
Experimental methods
Results
Discussion
　Rate law
　pH dependency
　Dissolution mechanisms based on step dynamics
Acknowledgments
References cited