The Burren is an amazing place. It is a karst limestone region of approximately 300 sq km which lies in the North West corner of Co Clare, in Ireland. It is composed of limestone pavements, which are eroded in a distinctive pattern known as karren. This pavement is crisscrossed by cracks known as grykes and underneath the pavement there are huge caves and rivers that suddenly flood when it rains.
It contains dozens of megalithic tombs and Celtic crosses and a ruined Cistercian Abbey from the 12th century, Corcomroe. You can find villages abandoned since famine times and green roads on which you can walk for miles without ever seeing a car. And if you go in springtime you will find rare wildflowers such as gentian and orchids and bloody cranesbill.
This area is known as the Burren about and is made up of huge slabs of limestone which were formed in the warm shallow seas of the Carboniferous ocean 340 million years ago
On the floor of this sea, shells, skeletons of plants and animals and coral were deposited and compressed and over millions of years formed limestone. Like our own bones the rock is high in calcium carbonate. These formations were pushed above sea level in some areas by huge earth movements e.g. earthquakes, etc.
Limestone is easily dissolved by rain water and erodes horizontal and vertical conduits in the rock . Rain water picks up carbon dioxide from the air and the soil and this acid seeks any weak points in the rock. It gradually seeps into these and enlarges them and dissolves the calcium carbonate in the limestone.
The water carries the calcium carbonate until it meets air again. As the water drops from the limestone it deposits small crystals of this as calcite, first as stalactites which hang from the ceiling. The water still has a residue of calcite in it and when it drops onto the floor this forms stalagmites and when they join they become columns or pillars.The Great Stalactite is very unique as it is unusual for stalactites to grow to this size
A new map of The Burren has just been published. This is available as an iPhone app or A3 size page. Find it at: www.truenorthmapping.ie