Kersanton

Kersanton, the name given to several varieties of igneous rock which are rich in plagioclase feldspar and dark mica, and contain carbonates. They occur in the form of dykes traversing the palæozoic rocks of Brittany. The name is from Kerzanton, a small hamlet on the Brest Roads. Granular varieties of kersanton are called kersantite, while those which have a marked porphyritic structure are known as mica-porphyrites.