On the north and north-eastern parts of this parish, in the vicinity
of the Camel, the land is fertile, resting on a rock which sometimes
resembles a calcareous schist, but more commonly that kind of
clay-slate which abounds in the calcareous series. This slate at
Penquean splits into very thin leaves, and is then quarried as a
roofing slate, but is softer and has less lustre, and is not so
durable as that raised at Delabole near Camelford. The south and
south-western parts of the parish consist of barren downs; the rock
forming the substratum is, however, very similar in appearance to what
occurs in the other division; but it contains more silex and is less
laminated, does not easily cleave, and is less susceptible of
decomposition than the former, and therefore produces only a meagre,
arenaceous soil.
ST. BREOCK IN KERRIER, or BREAGE.