These geochemical processes can also be ascertained from the
data gathered in this study. The relationship between Cl and Na
(Fig. 6) is shown in the three main clusters of water, a large group
corresponding to samples with lower contents of both species, lying
closer to the origin of the plot; a second one suggesting an enrichment
of Na independently of the conservative Cl anion (trend A in the plot);
and another group of water showing a common enrichment of the
two ions due to the influence of marine airborne salts and seawater
spraying (trend B in the plot). Marine airborne salts control rain water
chemistry over islands and coastal regions worldwide, thereby
influencing the evolution of groundwater composition (Berner and
Berner, 1996). Nevertheless, from Fig. 6 an excess of Na in relation to
Cl is shown, as the majority of the waters fall in the field above the
Cl_Na and seawater lines, suggesting other mineralization processes
in addition to the contribution of marine salts .