Volcano-tectonic structures, gravity and helium in geothermal areas of Tuscany and Latium (Vulsini volcanic district), Italy

Since the early 1980s, geological and structural mapping, gravity, and heli um soil-gas studies have been performed in the eastern sector of the Vulsin i Volcanic District (Roman Magmatic Province) in an attempt to locate poten tial geothermal reservoirs. This area is characterised by an anomalous geot hermal gradient of >100 degrees C/km, and by widespread hydrothermal minera lization, thermal springs, high gas fluxes, and fossil and current traverti ne deposits. The results of these surveys indicate the existence of a numbe r of fault systems, with N-S and E-W structures that appear to be superimpo sed on older NW-SE and NE-SW features, Comparison of the results of the var ious studies also reveals differences in permeability and potential reservo ir structures at depth. (C) 1999 CNR. Published by Elsevier Science I,td, A ll rights reserved.