F. Darragi, Y. Tardy
Jul 10, 1987
Citations
5
Influential Citations
67
Citations
Journal
Chemical Geology
Abstract
Abstract The mineralogical composition of salts and the chemical composition of brines of Lake Yoa (Ounianga El-Kebir, northern Chad) both reveal the neoformation of stevensite, a trioctahedral smectite, accompanied by aragonite. The coprecipitation of these two minerals clearly controls the evolution of pH, alkalinity, and Ca, Mg and silica concentrations in alkaline brines. The geochemical evolution characterized by a strong depletion of Ca and Mg in solution and an increase in alkalinity and pH is confirmed as the dominant process governing the formation of soda alkaline lakes.