Several peralkaline dykes up to a metre thick have been described from the central part of the Atsutla Range. The dykes are banded and contain abundant, zoned spherulites up to 6 mm in diameter of alkali feldspar, albite, quartz, riebeckite and aegirine. Rock analyses are available.
MATHEWS, W.H. and WATSON, K.D. 1953. Spherulitic alkali rhyolite dikes in the Atsutla Range, northern British Columbia. American Mineralogist, 38: 432-47.