Sans une interprétation précise des résultats du levé géophysique, le dépôt de classe mondial Neves Corvo aurait pu ne pas être découvert.
Neves Corvo is located in the western part of the Iberian Pyrite Belt. It is the largest Cu-Zn VMS deposit in the world, with reserves of 27.7 mt Cu rich and 23.1 mt Zn rich ores.
A 0.3 mGal anomaly was tested by drilling which intercepted sulphide rich sediments.
However, the numerical interpretation of the residual could not be explained by the sulphide horizon discovered in the upper sequence in the first hole. Drilling was then deepened. The massive sulphide lenses discovered at 400 metres explained the anomaly.