On the 25th of July 2023, DER Professors and CERENA Researchers, Orquídia Neves and José Manuel Marques, were present at the 24^th Anniversary of the Pavilion of Knowledge Centro Ciência Viva with the activity "Physical-Chemical Signatures of Natural Mineral Waters… function of the rocks through which they circulate".

Within the scope of this activity, the purpose was to show how the quick and “in situ” determination (in the field, next to the springs) of the Electrical Conductivity (EC) of natural mineral waters is an excellent indicator of their total mineralization.

To this end, examples of well-known natural and mineral waters were presented (Pedras Salgadas, Luso and Vimeiro) whose deep circulation is associated with distinct geological formations such as granites, quartzites and limestones/halite, respectively.

Samples of these types of rocks were also presented, explaining to the participants that the different chemical composition of these natural mineral waters depends on the rocks through which they circulate.

The participants were able to determine the EC of these waters, using a portable conductivity meter, usually used in field work, which allows measuring the EC of the waters expressed in μS/cm, a value that is of the same order of magnitude as the total mineralization of the waters expressed in mg/L.