The Leech 2 showings are on bluffs on the west flank of Mount Brussilof, overlooking the Mitchell River. Host rocks to mineralization are dolomitized carbonates of the Middle Cambrian Cathedral Formation. These are massive white to dark grey reefal carbonate. Where mineralized with magnesite and magnesian dolomite, replacement textures are common as well as some brecciation.

Magnesite mineralization is massive, coarse grained (greater than 10 millimetres) to sparry, buff, and forms large pods or lenses. Impurities include pyrite, calcite, white mica and rarely, talc. The mineralized zones extend along bluffs from the junction of Assiniboine Creek and Mitchell River to Struna Creek. Mineralized bluffs are typically rounded and buff in colour. The magnesite weathers out as discrete grains giving outcrops a sand-like mound appearance.

Samples of magnesite from mapping by G.B. Leech of the Geological Survey of Canada yielded values of 40 to 99 per cent MgO (calcined). Samples from exploration yielded MgO values of 87 to 99 per cent (calcined).

The bluffs were first examined in 1965 by the Geological Survey of Canada then examined by explorationists in 1969. Further mapping by the British Columbia Ministry of Energy, Mines and Petroleum Resources included sampling and the results are still pending (1990).