Cross-hole reflection seismic to delineate a relatively thin volcanogenic massive sulphide deposit in shale hosted environment

Abstract

The seismic reflection method is a high resolution technique that can be used in many exploration environments including mineral exploration. However, mountainous terrain, depth of burial and the steepness of ore bearing structures pose a challenge to the application of surface seismic in mineral exploration. The cross-hole seismic method may present an alternative approach under such conditions. Presented here is a synthetic study examining the capability of the cross-hole seismic method to delineate a volcanogenic massive sulphide ore body in a shale hosted environment. A simple model typical for volcanogenic massive deposits in Tasmania has been considered. There, an elongated steeply dipping volcanogenic massive sulphide deposit with an average thickness of 10 m is seated within a shale rock. The primary aim of the modelling is to test the capability of the technique to delineate relatively medium sized, steeply dipping volcanogenic massive sulphide lens in shale hosted environment. A second objective is to use the technique to prospect for extensions to mineralization along steeply dipping reflectors. Synthetic cross-hole seismic records were generated using a 120 Hz energy source. Kirchhoff VSP migration was applied to wavefield separated shot records and Pre-stacked Depth Migrated images created. The resulting migrated images correlate well with the position and dip of the ore body demonstrating the potential of the cross-hole reflection technique to delineate steeply dipping ore structures in challenging environments.