The field relations and petrography of a monchiquite vent, located five miles northwest of Fort William, Inverness-shire, Scotland, are described. The vent cuts the Moine series (Precambrian), contains xenoliths and xenocrysts, and is probably part of the igneous episode, of Permian age responsible for the monchiquite vents of the Midland valley and of the Orkney islands.

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