The Atna Peak area is underlain by Permian (?) and older meta- sediments which are part of the Central Gneiss Complex. Andalusite is present near Atna Peak within quartz-biotite schists adjacent to in- trusive rocks (Open File 1988-26, Figure 10). Locally, the andalusite forms porphyroblasts which range up to 10 centimetres in length and comprises a major constituent of the schists (Evenchick, 1979).