Metal-organic complexes in geochemical processes: Estimation of standard partial molal thermodynamic properties of aqueous complexes between metal cations and monovalent organic acid ligands at high pressures and temperatures

Insight into the enigma of Neoproterozoic manganese and iron formations from the perspective of supercontinental break-up and glaciation

“…Experiments of Desai & Ganguly (1980) showed the stability of Mn, Ba, Fe and Zn complexes (among others), depending on the type of chemical bonds and the type of organic matter. It was recently pointed out by Shock & Koretsky (1995) that metal-organic complexes are likely candidates for an efficient transport of metals in any geological environment. Therefore, the role of organic matter may be significant in transport processes of Ba (and also Fe, Mn?)…”

Some fundamental issues in computational hydrodynamics of mineralization: A review

“…Since any numerical model involves fluid properties and thermodynamic data, another important fundamental issue that researchers involved in modeling hydrothermal or mineralized systems are presently concerned with is to realistically represent fluid properties and chemical reactions at high pressures, high temperatures and high ionic strengths as one would find in ore forming systems. While numerous efforts have been made to develop new equations of state and new fluid property models in recent years (Barnes, 1997;Geiger et al, 2006a,b;Pokrovskii, 1999;Shock and Helgeson, 1988;Shock and Koretsky, 1995;Wang et al, 2010), some are with focuses on systems of geochemical importance such as aqueous solutions containing ions or neutral molecules that exist in significant amount in mineralizing systems (Anderko and Lencka, 1998;Lencka et al, 1997;Wang and Anderko, 2008;Wang et al, 2002). Such models can provide not only various fluid properties that are relevant to modeling hydrodynamics of mineralization, such as density, viscosity, surface tension, diffusivity, and thermal conductivity, but also the thermodynamic properties of chemical reactions that are necessary for describing the fluid speciation and mineral dissolution/precipitation reactions, as well as the energy/heat absorbed or released from chemical reactions.…”

“…To accurately determine the mass source/sink of a mineral, the thermodynamic properties of all chemical reactions involved in a mineralizing system under consideration have to be known. As quantitative modeling has become a standard procedure in geochemistry, there is a wealth of thermodynamic data available for a broad range of minerals, aqueous species and gases that allow the quantitative evaluation of mineral dissolution and precipitation (Barnes, 1997;Geiger et al, 2006a,b;Pokrovskii, 1999;Shock and Helgeson, 1988;Shock and Koretsky, 1995;Wang et al, 2010).…”

A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

“…As for the clay minerals, the solution is supersaturated with respect to kaolinite and illite during the entire course of the reaction and changes from undersaturated to supersaturated with respect to beidellite-K (a type of smectite) and montmorillonite-K (a type of smectite) at 144 h and 336 h, respectively. (1) ; (2) ; (3) ; (4) ; (5) ; (6) ; (7) , 200 o C, P sat ; (8) Assumed log K as same as Na species; (9) Shock and Koretsky (1995); (10) ; (11) for boehmite; (12) Robie and Hemingway (1995), 200 o C, P sat ; (13) Wolery (1978), 200 o C, P sat .…”

“…Thermodynamic data used in this report, calculated with the computer code of SUPCRT92 . (1) ; (2) ; (3) ; (4) ; (5) ; (6) McCollom and Shock (1997); (7) , 200 o C, P sat ; (8) Assumed log K as same as Na species; (9) Shock and Koretsky (1995); (10) ; (11) for boehmite; (12) Robie and Hemingway (1995), 200 o C, P sat ; (13) Wolery (1978), 200 o C, P sat . Table 9.…”