Abstract

The Atacama Desert is one of the driest regions on Earth, characterized by long-term hyperarid climate. However, there are regional gradients from hyperarid to arid conditions. Today, the hyperarid core, the area receiving less than 2 mm· a− 1 precipitation, is situated between 19 and 22 S. In the past, regional climate changes caused local pluvial phases in the hyperarid Atacama and possibly shifted aridity gradients. We investigated the distribution of gypsum, nitrate and further water-soluble mineral phases along WE transects in the northern, central, and southern part of the Atacama Desert to identify correlations with the degree of aridity. The main mineral composition was determined by XRD analyses. Thermogravimetric analyses were used to quantify the gypsum content. Furthermore, samples were leached and leachates were analysed by ICP-OES and MTPR to identify water-soluble mineral phases.