Surface energy and strain effects on calcite dissolution

• Applicant: Professor Dr. Andrew Putnis
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2006 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 27603184

• Final Report Year: 2011

Final Report Abstract

1. The results of the project on the dissolution of stressed calcite consistently showed reprecipitation features despite using different set-ups to induce the stress as well as a range of fluid compositions. This emphasised the importance of the "boundary layer" when interpreting the mechanism of fluid-mineral interaction. This layer of fluid at the interface with the solid controls the coupling between dissolution and precipitation which is the mechanism by which one phase is replaced by another during any reequilibration of a solid in the presence of a fluid with which it is out of equilibrium. This concept has guided the interpretation of mineral replacement reactions in terms of the mechanism referred to as "interface-coupled dissolution-precipitation". 2. The results of the project on the effect of salinity on calcite dissolution have opened a new research direction focussing on how additives to a solution can alter the hydration state of any ions which may be incorporated into a crystal during growth. This has important implications to ion partitioning and trace element composition, which is relevant to the use of trace elements as climate proxies.

Publications

• The mechanism of reequilibration of solids in the presence of a fluid phase. Journ. Solid State Chemistry 180, 1783-1786 (2007)
  Putnis A. and Putnis C.V.
  
• The effect of specific background electrolytes on water structure and solute hydration: consequences for crystal dissolution and growth. Geochim. Cosmochim. Acta 72, 4476-4487 (2008)
  Kowacz M. and Putnis A.
  
• Effects of salinity on the morphology of dissolution pits in calcite - implication for CO 2 sequestration in carbonate rocks. In: Conference Porceedings of the International Symposium of Core Analysts. Noordwijk, The Netherlands, September 2009
  Zhang X., Putnis A., Putnis C.V. and Spiers C.J.
  
• Mineral Replacement Reactions. In: Thermodynamics and Kinetics of Water-Rock Interaction. Oelkers E. H & Schott J (eds). Reviews in Mineralogy & Geochemistry 70, 87-124 (2009)
  Putnis A.
  
• The role of background electrolytes on the kinetics and mechanism of calcite dissolution. Geochim. Cosmochim. Acta 74, 1256-1267 (2010)
  Ruiz-Agudo E., Kowacz M., Putnis C.V. and Putnis A.