Tectonic control of volcanism in an uranium province

The evolution of the highly uraniferous volcanism in the Tyrrhenian area is presented in relation to the tectonic evolution of the Tyrrhenian Basin and of the Apennines. The tectonic and magmatic evolution suitably reflect the effects of low viscosity fluids rich in O-H-C (''mantle metasomatic fluids''). It has been demonstrated that these fluids are able to effect the substantial addition of radioactive elements to a magma, after its separation from the mantle-source region and during its storage in the upper crust. The discovery that, even in magmas, the uranium content derives from a multi-stage process because of the continuous supply of the element from depth, provides new insight into the geology of uranium