This parish extends southward from the church to the foot of the
granite hills near Roughtor. The northern part consists of the same
rocks as St. Cleather. On the common near the church numerous large
blocks and boulders of rock occur, composed of crystalline hornblend,
in a basis of compact felspar. It resembles the rock already noticed
on the side of the hills descending to Pollaphant, in the parish of
Alternun.