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Title3D diffraction and mode-converted scattering signatures of base metal deposits, Bathurst Mining Camp, Canada
AuthorMalehmir, A; Bellefleur, G; Müller, C
SourceFirst Break vol. 28, no. 12, 2010 p. 41-45,
Alt SeriesEarth Sciences Sector, Contribution Series 20100212
PublisherEAGE Publications
Mediapaper; on-line; digital
File formatpdf
ProvinceNew Brunswick
AreaHalfmile Lake
Lat/Long WENS -66.0000 -65.5000 47.5000 47.2500
Subjectseconomic geology; geophysics; geophysical surveys; seismic surveys; seismic reflection surveys; base metals; mineral deposits; Bathurst Mining Camp
Illustrationsprofiles; models
ProgramTargeted Geoscience Initiative (TGI-4), Volcanogenic Massive Sulfide Ore Systems
AbstractThe localized and isolated nature of base-metal deposits can generate a complex scattered wavefield that may include P-P, P-S, S-P, and S-S events. Multi-component VSP data have previously confirmed the presence of several wave types scattered by a deep-seated base metal deposit at Halfmile Lake, Bathurst Mining Camp, Canada. However, mode-converted waves scattered from a massive sulphide deposit have not previously been recognized on surface seismic data. In this study, we used 3D surface seismic data acquired with an explosive source and vertical geophones to investigate the possible presence of P-P, P-S, S-P, and S-S events scattered at a base metal, lens-shaped body at about 1.2 km depth. We show that this body produces a diagnostic P-P diffraction and use finite-difference modelling to show it could produce mode-converted scattered signals. Results from a target-oriented azimuthal scattering analysis based on 3D prestack migration reveal amplitude anomalies at the location of the base metal lens for S-P waves and possibly P-S waves. The identification of these events confirms that mode-converted waves scattered from the deep sulphide lens were recorded on the 3D data. However, the real potential of these complementary wave modes for mineral exploration will only be realistically evaluated using P- and S-wave sources and multi-component receivers.