Direct VMS Targeting through Preserved Relative Amplitude Processed Seismic Imaging at Neves Corvo, Portugal

Abstract

Exploration of deep VMS deposits at the Neves Corvo mine on the Iberian Pyrite Belt was further advanced through a specialised application of surface seismic techniques. The contrast in impedances from elastic property measurements of core samples showed that there should be a significant difference in the seismic response of mineralisation compared to the surrounding host rocks. These results indicated that relative amplitude preservation processing may be of importance to help reduce the ambiguity in direct, seismic amplitude anomaly based targeting of Volcanogenic Massive Sulphides. However, such processing was not easy to implement due to an intrinsically low signal to noise ratio, complex 3D geology, high scattering level and often patchy and poor reflectivity. The newly obtained 3D seismic cube was calibrated with the existing boreholes to show superior ore zonation and precision required for the subsequent deep drilling campaign.