Muds and salts from Laguna Mar Chiquita (or Mar de Ansenuza), Córdoba, Argentina: natural materials with potential therapeutic uses

Abstract

The Laguna Mar Chiquita, located in Cordoba´s province, Argentina, is the largest saline lake in South America, with a variable surface between 2,000 to 6,000 km2. During the last 50´and 60´ the mud collected directly from the bottom of the lake was extensively used for topical application over the skin and the salts precipitated in the coast were used for domiciliary baths. Subsequent water level increases (decades of the 70, 80, 90) diminish the possibility of using these materials. However, during the last decade the decline of water levels has increased the potential for reuse of muds and salt deposits of this lake. The aim of this study was to characterize the composition of the muds and salts obtained from Laguna Mar Chiquita like natural materials with potential therapeutic uses. The salinity of the water, 28 to 360 g/L like minimum and maximum reported, has reached in the last decades values as low as 33 g/L, with salt contents above 70 g/L at the present. The predominant dissolved anion was chloride while sodium was the most important cation. Sulphate was present in minor proportions in the water but it was the most important anion in the precipitated salts. The pH was neutral or slightly alkaline. The dominant composition of the mud, with possible therapeutic application, was a mixture of illite-like predominant phyllosilicate, quartz, plagioclase, feldspar, muscovite, calcite and halite. Waters and muds from Laguna Mar Chiquita showed significant similarity to those from the Lo Pagán in Mar Menor, Murcia, Spain, place in which widely promoted tourism is related to the use of muds with therapeutic purposes.