An investigation of finite-difference seismic modelling applied to massive sulphide exploration

Seismic exploration is an excellent method for massive sulphide exploration because of its sensitivity to density and velocity changes. The density contrast between sulphides and host rocks is significant enough that contacts between these rock types are visible in seismic data.; New 2D acoustic finite difference modelling was completed for this study, simulating a combination of one surface seismic and two VSP arrays over a hypothetical massive sulphide deposit. The results from a scattering massive sulphide body in a scattering host rock have shown that added value is obtained from simultaneous recording of surface and VSP data and concurrent processing of the resulting data. For best results, pre-migration processing of the VSP data should include wavefield separation to remove downgoing energy followed by concurrent pre-stack depth migration. This study shows simultaneously recorded data from a surface and two vertical seismic profile (VSP) arrays decrease the effects of an attenuating surface low velocity layer and the irregular geometry of mineralisation.; Examination of the imaging properties of the model space indicate that for optimal imaging results, the VSP arrays should be placed on either side of the expected target extending at least to target depth, with the surface array crossing the target and connecting the two VSPs.