Volcanic Carns / Precambrian Rhyolites ( light coloured rock - extrusion of an
acid magma - fine grain ) / 600 million years old / above Treffgarne Gorge
Volcanic Carns / Precambrian Rhyolites ( light coloured rock - extrusion of an
acid magma - fine grain ) / 600 million years old / above Treffgarne Gorge