BLAIR JONES AND THE GEOCHEMICAL EVOLUTION OF SALINE LAKES

Blair Jones was one of the key voices in the development of the “Eugster-Hardie” model of brine evolution in the 1960's and 1970's. This model is based on the "Chemical Divide", which stipulates that when a binary salt precipitates from brine, if a solute is much lower in concentration, it will be effectively removed from solution. This allows the remaining solute to continue to build up in concentration. Although it is a bit of a simplification, the principle is nevertheless an important consideration in determining the composition of continental saline waters.

One of Blair's last projects was to revisit these now-classical models of brine evolution, develop new related ideas, and test their continued applicability to the geochemical diversity of saline lakes around the world. Over the years, Blair emphasized the utility of simple numerical models, such as SNORM, the Salt Norm, which calculates the normative salt assemblage that would precipitate upon complete evaporation. He used these models and simple ternary plots to understand the genesis and evolution of evolving brines, providing powerful predictive and interpretive tools in understanding the evolution of lake basins. Blair’s work spanned the globe, including important contributions to understanding continental saline waters and basins on four continents, including the Great Salt Lake, Australia’s Murray Basin, Saline Valley of California, Lake Abert in Oregon, Lake Magadi in Kenya, and others. Among Blair’s recent contributions in this area are several important ideas, including that both the initial Ca/Mg ratio of average dilute inflow and the rapidity of calcium depletion are important in determining whether residual brines are dominated by sulfate or carbonate. This work was published in the Treatise on Geochemistry (Jones and Deocampo, 2003; Deocampo and Jones, 2014).