The West Tuya lava field is located about 95 kilometres north-north-west of Dease Lake, British Columbia. This report presents an overview & summary of field work, geographic information system spatial analysis, and preliminary petrographic analysis conducted at the field in 2003-04. Highlights of this work include: identification of three sub-aerial shield volcanoes and their mineral composition; confirmation that mantle-derived peridotite inclusions are present at two of the volcanoes; and interpretation of the sub-aerial lava flows. The minimum and maximum volumes of material erupted are also estimated.

This paper describes a novel, high-resolution application of cross-borehole seismology at the Snap Lake diamond mine, Northwest Territories, to assess whether the relatively thin kimberlite dyke that hosts the diamonds could be mapped underground with sufficient resolution to accurately estimate its volume and to guide mining. Subsequent mining and mapping with the 50-by-70-metre test panel indicated whether the technique was able to map the top & bottom surfaces of the dyke and to identify ramps, pinch-outs, and cross-cutting fracture planes. The tests also compared the performance of that new technique with two other geophysical methods, high-frequency vibrating seismic surveying and ground penetrating radar.