Longitude: -76.48, Latitude: 47.18
A small crescentic mass of nepheline syenite outcrops 1 km south of Nadon Bay on the southern side of Cabonga Reservoir. Enveloped in Precambrian gneisses and amphibolites, the rock consists of plagioclase, nepheline, biotite, muscovite and corundum, with sodalite apparent in hand speciments.
K-Ar on biotite gave 894 Ma (MacIntyre et al., 1969), but this is probably only dating a metamorphic event.
LAURIN, A.F. 1960. Preliminary report on Tubquetil-Emard area Pontiac Electoral District. Preliminary Report, Quebec Department of Natural Resources, 424: 1-9. MACINTYRE, R.M., YORK, D. and GITTINS, J. 1969. The K-Ar characteristics of nepheline. Earth and Planetary Science Letters, 7: 125-31.
Earth > North America > Canada > Quebec