This occurrence is located 250 metres north of Highway 3, just east of Morrissey Creek, approximately 4 kilometres due east of Grand Forks.
A 30 to 60 metre thick bed of biotite schist (mica gneiss), containing several 10 to 30 metre thick lenses of dolomite, extends eastward from Morrissey Creek along the base of a bluff for at least 488 metres. The bed lies within high grade metamorphic rocks of the Proterozoic and possibly Paleozoic Grand Forks Gneiss. The rocks are intruded by bodies of pegmatitic gneiss and andesitic to dacitic dykes. Bedding in a quarry just east of Morrissey Creek, strikes 110 degrees and dips 75 degrees south. Across the creek to the west, a 30 metre thick band of dolomitic limestone and overlying biotite- hornblende migmatite, strike north and dip 30 degrees west. This suggests that a fault separates the two sequences on either side of Morrissey Creek.
The deposit is comprised of medium to coarse grained (2 to 6 millimetres), brownish weathering, white dolomite, containing scattered streaks and spots of light green to yellowish green serpentine, flakes of yellow to light brown phlogopite and vein like bodies of feldspar. Various other minor constituents include calcite, forsterite, diopside, spinel, anthophyllite, tremolite, biotite and apatite. A sample of randomly collected chips from the quarry east of Morrissey Creek contained 30.86 per cent CaO, 20.69 per cent MgO, 1.19 per cent insolubles, 0.98 per cent R2O3, 0.49 per cent Fe2O3, 0.039 per cent MnO, 0.03 per cent P2O5, 0.004 per cent sulphur and 46.20 per cent ignition loss (Geology, Exploration and Mining in B.C. 1970, p. 491). Dolomite reserves are estimated at 1 million tonnes (Assessment Report 13176, p. 14).
The dolomitic limestone west of Morrissey Creek is medium grained and white in colour. Chert beds are prominent within this unit. The limestone contains minor diopside, mica and serpentine.
Dolomite and limestone were initially quarried here for building stone and lime as early as 1916. Ramshead Quarries Ltd. quarried the dolomite for building stone from 1968 to 1971. V.T.S. Quarry Ltd. performed some minor exploration work for agricultural lime in 1984. No production figures are available.
