The role of the Serranía del Burro range in the distribution and hydrochemical behavior of water resources in Coahuila, NE Mexico

Abstract

Highlands form one of the essential links ensuring the good performance of the hydrological cycle on Earth, and significant amounts of good-quality water are concentrated in these areas and distributed to lowlands. These resources are indispensable for arid/semi-arid regions such as NE Mexico, where water is scarce and sometimes lacks good quality. In the state of Coahuila, the Serranía del Burro is one of the most important hydrogeological systems, and at least seven aquifers show some type of relationship with this system or benefit from its recharging. In this paper, data from 50 well and spring samples are presented with the goal of identifying the effect of the range on the chemical composition of the surrounding aquifers and the mechanism of recharging. The results show that in this area, the waters are mostly of the type Ca2+-Mg2+-HCO3-, with minor contributions from more saline and mixed waters. The main processes responsible for the chemistry of the waters are water-rock interactions, mixing and, cationic exchange, in which, the weathering of silicates and, the dissolution of carbonates through karst processes predominates. Recharging is characterized as fresh and deep, due to the influence of karst and tectonic phenomena throughout the geology of the Serranía del Burro and the adjacent areas. Limited shallow meteoric percolation occurs in the NO of the Serranía del Burro due to the presence of conglomerates and caliche sequences, resulting in low permeability. This study highlights the need to take care of good-quality water resources located in the mountains; adequate exploration work must be carried out in these areas, since waters of questionable quality prevail throughout the state, mainly due to natural salinization processes in lowland areas.