The Brown Creek occurrence is located 0.8 kilometres up Brown Creek on the west side of McNaughton Lake, approximately 6.44 kilometres south-southeast of Boat Encampment. Warsaw Mountain is located approximately 2.5 kilometres to the southwest.

The area is underlain primarily by folded metasedimentary rocks of the Hadrynian Horsethief Creek Group. Upper amphibolite facies metamorphic conditions were reached in the northern Monashee Mountains at circa 100 Ma (Geology Vol. 18, pp. 103-106). An expanded description of the regional geology is given in the Warsaw Mountain showing (083D 041).

At the Brown Creek occurrence, kyanite is present at the contact between the Aluminous Pelite unit (Open File 1988-26) or the equivalent Lower Pelite (Geological Survey of Canada Open File 2324) and Lower Grit unit (Open File 1988-26 and Geological Survey of Canada Open File 2324) of the Horsethief Creek Group. The Aluminous Pelite or Lower Pelite unit consists of pelitic schist, locally kyanite-sillimanite-staurolite-garnet-biotite and/or muscovite- bearing, quartzofeldspathic psammite, conglomerate with clasts of marble, calcsilicate rock, quartzite and granite, and concordant and discordant amphibolite. The Lower Grit unit consists of granule conglomerate, quartzofeldspathic psammite and grit, minor pelitic schist and amphibolite. Kyanite occurs in pelitic schists with greyish-blue crystals, 0.6 to 7.0 centimetres long, locally comprising 10 to 20 per cent rock volume.