Brudenell and Raglan Areas

The northeastern end of the main continuous section of the Haliburton-Bancroft nepheline syenite-syenite gneiss belt lies in the townships of Brudenell and Raglan, with a more southerly belt in Lyndoch Township, the Wolfe Belt, which is described separately (031-00-097). Excluding the Wolfe Belt there are six occurrences of nepheline syenite in the area (Hewitt, 1961, p. 83) and all are of gneissic rocks of very varied mineralogy. They are conformable with marbles, paragneisses, amphibolites and syenitic gneisses, and do not cut any other rock types, but are themselves cut by nepheline-bearing pegmatites and intruded and replaced by syenite, granite, granite gneiss and granite pegmatites. They have been metamorphosed and the characteristic minerals present are oligoclase, nepheline, hastingsite, aegirine, scapolite and garnet. At the Klondike corundum cuts and the Craigmont workings in Raglan Township corundum was formerly worked and rock types include oligoclase-magnetite-corundum-muscovite rocks and plagioclase-corundum-nepheline rocks of which the last mineral comprises 80%. Near Reid Lake interbanded gneisses consist of nepheline-scapolite, scapolite-biotite and nepheline-plagioclase gneisses, the scapolite-rich rocks usually being free of plagioclase. Corundum occurs at most localities and is locally abundant in the gneisses and in later cross-cutting syenite pegmatites.