Halitefacies in the salar del Rincon, Andes Department, Salta

Abstract

Salar del Rincón is located at 3,660 m.a.s.l. in the Andes district, Salta province, and northeast of the Southern Puna. This paper shows the results of the borehole correlation that helped determine the halite facies, textures, structures, interstitial clastic material, mineralogy, chemical composition of the brine and the aquifer hydraulic parameters determineted in an E-W transectthat covers approximately 30 km². The crystalline phase is mainly made up of halite with gypsum, mirabilite, thenardite, glauberite, hydroglauberite, eugsterite, calcite, and ulexite only in the western area of transect. The following halite evapofacies were identified: saline crust, geodes and banded halite. The observed textures include: crystal hoppers, chevron folds, muddy halite and cloudy halite. The brine composition is sodium chloride with variations in sulphate and borate at depth. The cations are Ca, Mg, Li and K. The K/Li relationship is 20/1. The reserve estimated at a mineral resource level in areas with different effective porosity was 208,2 kt for Li⁺ and 4231.9 kt (> 30 %) for K⁺;14.9 kt for Li⁺ and 302.9 kt (< 10 %) for K⁺. The Li⁺and K⁺ contents in the entire transect are 223.1 kt and 4534.8 kt, respectively. Research carried on contributed to determine an average concentration of 0.4 g/l of lithium and 8 g/l of potassium.