Reflection seismic imaging and physical properties of base-metal and associated iron deposits in the Bathurst Mining Camp, New Brunswick, Canada

The Bathurst Mining Camp, northern New Brunswick, Canada is a major base-metal producing region that includes the Brunswick No. 12 and smaller past-producing Brunswick No. 6 deposit. Sustaining mining activity in the camp requires exploration of orebodies near and adjacent to existing mines. In this paper, we recovered, re-processed, modeled and interpreted a 2D high-resolution reflection seismic profile in the vicinity of the Brunswick No. 6 open pit with the aim of providing key information on the geological structures associated with mineral deposits at depth. The seismic data quality is good to excellent with numerous strong reflections in raw shot gathers, resulting from a careful survey design that included test shots and a priori considerations for the geological environment. Physical properties of lithological units and mineralized zones including gamma–gamma, conductivity, magnetic susceptibility, density and sonic data were studied from borehole geophysical measurements conducted near the mine. This helped to correlate seismic data and shows that the Brunswick Horizon, a key ore-prospecting horizon, and associated lithological contacts are strongly reflective. The results demonstrate that reflection seismic imaging has been particularly effective for imaging steeply dipping structures of the Brunswick No. 6 deposit many of which intersect the surface and thus allow for correlation with surface geology. Massive sulfides and iron formation of the Brunswick Horizon are identifiable locally within a distinctive reflective package that can be used as a broad guide in the region for the exploration of deep base-metal deposits. In several locations, a change from highly reflective to semi-transparent seismic character is explained by the presence of faults that juxtapose highly reflective lithological units with seismically transparent lithologies.

Research Highlights
► Reflection seismic data from the Brunswick No. 6 deposit are recovered, processed and interpreted in conjunction with physical property measurements.
► Results clearly show major geological structures that host the Brunswick Horizon.
► A high-amplitude steeply-dipping reflection observed within a reflective package is interpreted to originate from the Brunswick Horizon.