Etude géochimique et isotopique des aquifères dans la zone de Maicao (Colombie) / Study of the geochemistry and isotopic composition of aquifers in the Maicao region (Columbia)

Abstract

A combined study of the hydrochemistry and environmental isotopes was carried out in the aquifers in the region of Maicao, in northern Colombia. The aim is to develop a conceptual circulation model for better management of the water resources. Three sedimentary aquifers can be defined by their geology: Cretaceous and Quaternary, which are unconfined, and a confined Tertiary zone. Two types of groundwater were identified. The first, of moderate salinity and having a recently renewed part (less than 50 years) is located in the Cretaceous aquifer and in a sector of the Quaternary aquifer near the Carraipía River (main surface water body in the study area). The second, of higher mineralization and older (more than 7900 years BP), which also shows more depleted isotopic values compared to the first group, is represented by the Tertiary aquifer and the Quaternary aquifer outside the zone of the Carraipia River. The absence of any actual recharge to the Quaternary aquifer, the most used water resource, enhances the need for the setting up of a rigourous regional water management policy. Copyright © 2009 IAHS Press.