ABSTRACT
Significant progress has been made in understanding the mechanistic details of dissolution dynamics on the (104) cleavage surface of carbonate minerals. Much of this recent work has focused on AFM observations of the rate of step and kink movement (e.g. Liang et al. 1996a, b, Jordan & Rammensee 1998, Lea et al. 2001, Higgins et al. 2002). Observations of dissolution rates over larger lateral scales have also provided basic insight into the relationships of etch pit development and defect distribution (MacInnis & Brantley 1992, 1993, Luttge et al. 2003), as well as comparison with the overall "bulk" rate measured in mineral powders (Arvidson et al. 2003). In addition, considerable insight has been generated by integrating surface complexation models and observations (Van Cappellen et al. 1993, Stipp et al. 1994, Pokrovsky et al. 1999, Fenter et al. 2000, Pokrovsky & Schott with an atomistic description of surface topography and measurement of step velocities (Duckworth & Martin 2003). This general approach also has the potential to yield substantial detail regarding inhibition mechanisms in dissolution reactions as well. In this brief paper, we describe preliminary experimental observations of magnesium inhibition of calcite dissolution, and suggest how this inhibition may be related mechanistically to site-specific surface properties.
