Without accurate interpretation of the results of geophysical surveys, the world-class Neves Corvo may not have been discovered.
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.