The Bagnore and Piancastagnaio geothermal fields of the Monte Amiata volcanic area (Figure 1) have been under exploitation for about half a century. Numerous geologic studies have been performed in this area due to its mining and geothermal peculiarity. Recently, environmental interest arose for the presumed interactions between the important shallow aquifer hosted within volcanites and the geothermal reservoir. 

In the ’60s, stable isotopic determinations demonstrated the prevailing meteoric origin of geothermal fluids (Craig, 1963 and Nuti, 1991 and references therein), proving the renewability of this kind of resource. As a consequence, all the conceptual geothermal models take into account a meteoric recharge. The geothermal monograph on Amiata (Calamai et al., 1970) assumes the occurrence of a recharge area not far from the production zone. In this approach, the outcrops of reservoir formations, or other rocks hydraulically connected with them, should be not too far and of suitable extent to justify production data. The volcanic necks, although not well defined on site, were indicated as likely preferential pathways for local and partial meteoric recharge.
In this paper the main results of recent studies and of the production history of the Amiata fields are summarized in order to revise and update this model.