Extract from MINFILE No 104P 024:
The fault bounded Horseranch Range is located approximately 85 kilometres south of Watson Lake, Yukon Territories. It has been suggested that these rocks may form a metamorphic core complex (Plint, Fieldwork 1987). The area is underlain by moderately west-dipping sedimentary and foliated metamorphic rocks of the Cambrian and/or earlier Horseranch Group. Pegmatite dykes, commonly parallel to foliation, intrude quartzites and mica schists in a zone 750 metres wide and 5 kilometres long. The pegmatites are composed of feldspar, quartz, muscovite, lesser amounts of tourmaline and garnet and minor pale-green beryl. Pegmatites are rarely zoned, with muscovite-tourmaline-rich margins and quartz-rich cores. Beryl occurs as hexagonal prisms 0.5 to 1.0 centimetres across and 1 to 2 centimetres long. Overall average beryllium content of the pegmatite was visually estimated to be less than 0.1 per cent (Minister of Mines, Annual Report 1955, pp. 9,10).
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