Kerry Yellow Sandstone

Notes:

A fine-grained yellow sandstone deposited in a desert environment during the Devonian period 400 million years ago, which overlies the red-purple clastic "Dingle Beds". Used as a building stone in Co. Kerry for over 800 years including at Ardfert Cathedral, where field stones of this material can be found. These units are part of the Old Red Sandstone, a thick sequence of Devonian rocks, including conglomerates, sandstones, mudstones, siltstones and thin limestones, that were deposited 416 - 360 million years ago. This sequence is continental in origin and was formed through the deposition of rocks into structural basins between the Caledonian mountains. The sediments are poorly sorted and colours range from yellow, green and grey through to red and purple (due to iron oxide content).