This extensive and interesting parish is entirely situated within the
boundaries of the calcareous series. The prevailing rock is a blue
argillaceous slate, the surface of which, when perfect, is either
glossy and irridescent, or finely striated: it alternates with several
kinds of massive or coarsely lamellar rocks, into which it gradually
passes. These rocks present the following varieties: a fine grained
rock abounding in scales of mica; a variety of greenstone or cornean
quartz rocks; and dark-coloured limestone.
This suite of rocks offers many objects worthy of a minute inquiry,
far beyond the limits of these short notices.