A vermiculite prospect outcrops 14 kilometres southeast of the community of Fraser Lake, in an area underlain by granite, granodiorite and quartz diorite of Jurassic age.
A road-cut exposes a zone of reddish orange weathered, medium grained granodiorite, 75 metres long, containing mica flakes which swell when heated with a propane torch. Fresh medium-grained granodiorite outcrops along a ridge immediately northeast of this zone. The granodiorite contains mica flakes, that also expand on heating, throughout much of the exposed area.
Exfoliation tests were carried out on a sample of vermiculite by CANMET, Energy, Mines and Resources Canada. Vermiculite content of the tested sample averaged 5.6 per cent (Fieldwork 1990, p. 267, Table 3-1-2). The material may be too fine-grained for use as loose insulation; 91 per cent of the vermiculite was found to occur in size fractions below 1.40 millimetres. Bulk densities of the minus 1.40 millimetre size fractions, ranged from 326 to 427 kilograms per cubic metre, above the ASTM range of 88 to 128 kilograms per cubic metres specified for loose insulation.