
Geologically speaking, Salinas de Maras lies above the Maras Formation in the Cusco Department of the Andes. The source of the spring water is believed to be from a deep halite deposit within the Maras Formation, dating to 110 million years ago (1). Geologists believe that millions of years ago, an ocean covered much of central Peru (2). During the Andean orogeny (mountain building event), these ocean waters were trapped inland, and through evaporation, formed halite deposits that are now the source of the hypersaline spring water, and Salt of the Earth Co. salt.
(1) Maturrano, L., Santos, F., Rossello-Mora, R., and Anton, J. 2006. Microbial Diversity in Maras Salterns, a Hypersaline Environment in the Peruvian Andes, Appl. Environ. Microbiol. 72:3887-3895.
(2) Instituto Geologico del Peru. 1989. Entorno geologico de las rocas y minerales industriales. Datos Geol. Peru 2:10-45.