Dissolved potassium in the shallow groundwaters circulating in the volcanic rocks of central-southern Italy

It turns out that the attainment of saturation with sanidine, during early stages of rock dissolution, limits K concentration in the Monte Amiata groundwaters to around an average of 2.9 ± 1.3 mg L−1 (1SD). In the silica undersaturated Roman Magmatic Province, saturation with leucite is not attained during the evolution of groundwaters and, consequently, K concentration reaches comparatively high levels, with an average of 24.6 ± 27.1 mg L−1 (1SD). Most of these unusually high K concentrations are due to natural weathering of silicates without any anthropogenic influence.