Following extensive petrophysical studies and presite surveys, the Trill area of the Sudbury basin was selected for conducting the first 3-D seismic survey for mineral exploration in North America. The 3-D seismic experiment confirms that in a geological setting such as the Sudbury Igneous Complex, massive sulfide bodies cause a characteristic seismic scattering response. This provides an excellent basis for the direct detection of massive sulfides by seismic methods. The feasibility study suggests that high‐resolution seismic methods offer a large detection radius in the order of hundreds to thousands of meters, together with accurate depth estimates.

Reflection seismic and borehole geophysical data place important constraints on the subsurface geometry of the Sudbury Structure, which is the site of the world's largest Ni‐Cu camp. Seismic reflections can be traced from outcrop within the Sudbury North Range to about 4.5 km depth beneath the center of the Sudbury Basin, where the layer thickens abruptly from 1 to 3 km. Further south the North Range norite can be followed to about 10 km depth beneath the South Range. Borehole studies show systematic variations of p‐ and s‐wave velocity, Poisson's ratio and density within the Igneous Complex. Quartz‐rich granophyre is distinguished from the norite and footwall rocks by relatively low Poisson's ratios (0.20–0.23 versus 0.23–0.25). These changes in physical rock properties define an important subdivision of the Igneous Complex, compatible with a simple model involving differentiation of melted crustal rock into dominantly felsic and mafic components. This study documents the importance of interlayering to the seismic reflection response of the crystalline crust.

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Multi-offset vertical-seismic-profiling (VSP) techniqueswere employed in the JAPEX/JNOC/GSC et al. Mallik 3L-38 observation well to image the gas hydrate zones in the immediate vicinity of the Mallik 5L-38 gas hydrate production research well. Conventional vertical-seismic-profiling - common-depth-point (VSP-CDP) transforms of the reflected wave field and resonance-scattering analysis from three-component VSP data provide information about lateral distribution of the gas hydrate and the internal structure of the gas hydrate zone. Compressional-wave velocities beneath the permafrost and within the gas hydrate zone averaged 2040 m/s and 2470 m/s, respectively. Within the gas hydrate zone, shear-wave velocities averaged 1100 m/s. At the Mallik well site, the gas hydrate zone is characterized by strong perturbations in compressional-wave velocities. The resonance-scattering analysis and full wave-form sonic logs from the JAPEX/JNOC/GSC Mallik 2L-38 and JAPEX/JNOC/GSC et al. Mallik 5L-38 wells indicate that important lateral variations in gas hydrate distribution must exist near the top of the gas hydrate zone, at about 900 m depth.

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