What is it?
The Burren is an area of karst covering approx. 36,000 hectares (140 sq. miles) in north Co. Clare and a small part of south Co. Galway in Ireland. Karst is defined as "rough limestone country with underground drainage" (Chambers), and practically everything you need to know about The Burren can be described in terms of these two elements - stone and water. From its original formation, to how it appears and is used today, the interaction of stone and water has been the defining feature of The Burren.
How was it formed?
Around 650 million years ago, that part of the Earth's crust now occupied by Ireland was located near the Equator at the bottom of a shallow sea. The marine life (much of it microscopic) included organisms with hard shells composed of calcite. When they died, the shells settled on the floor of the sea. Over millions of years, these shells compressed and cemented to form the limestone rock that we see today all over The Burren. This is a simplified description - in fact there are many layers of different types of limestone reaching in places to a depth of almost 800 meters. Some of the layers are separated by thin sheets of clay known as palaeosol. The limestone was finally covered (about 318 million years ago) by the second type of rock associated with this area, known as Clare shale. Shale is formed in slow-moving water when very fine mud that has been washed down by rivers settles. The Clare shales are about 2,500 meters deep in places and once covered all the limestone in The Burren. The final phase in the formation of The Burren happened during the various Ice Ages when the glaciers advanced generally southward and stripped away the covering of shale to expose the underlying limestone. The end of the last Ice Age in Ireland is dated to 12,000-10,000 BC.
The Cliffs of Moher (Irish: Aillte an Mhothair, lit. cliffs of the ruin, also known as the Cliffs of Mohair) are located in the parish of Liscannor at the south-western edge of the Burren area near Doolin, which is located in County Clare, Ireland.[1] The Cliffs are currently one of the 28 finalists for The New7Wonders of Nature. (The official list will be declared in 2011.)
The cliffs rise 120 meters (394 ft) above the Atlantic Ocean at Hag's Head (Irish: Ceann na Cailleach), and reach their maximum height of 214 meters (702 ft) just north of O'Brien's Tower, eight kilometres away.[2] The cliffs boast one of Ireland's most spectacular views.[3] On a clear day, the Aran Islands are visible in Galway Bay, as are the valleys and hills of Connemara.
O'Brien's Tower is a round stone tower at the approximate midpoint of the cliffs. It was built by Sir Cornelius O'Brien, a descendant of Ireland's High King Brian Boru, in order to impress female visitors.[4] From atop that watchtower, one can view the Aran Islands and Galway Bay, the Maum Turk Mountains and the Twelve Pins to the north in Connemara, and Loop Head to the south.
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