Abstract

The provenance of saline inputs to the Salar de Atacama has been studied by means of the isotopic composition of sulphates dispersed in drilling core samples and the analysis of the water of surface inflows. The pattern shown by the ratios of Sr-87/Sr-86 and the isotopic composition of sulphur and oxygen in sulphates, suggests a mixing of two water inputs: one coming from the northeast of the basin, higher in Sr-87/Sr-86, delta(34)S,d delta(18)O and the other from the south-west, lower in Sr-87/Sr-86, delta(34)S and delta(18)O. Analysis of the recent inflows to the Salar have confirmed the existence of two solute sources: northern and eastern inputs show an enrichment in those elements related to hydrothermalism and volcanism, in relation to water present in the west of the basin. (C) 2000 Elsevier Science B.V. All rights reserved.