How Was the Burren Formed by Erosion?

Forest and Soil Loss

• According to Clare County Library, the Burren held forests and fertile soil during prehistoric times. Early settlers cut down the forests, built farms and allowed animals to graze. Over time, the loss of the forest allowed rain to wash away the soil, exposing the limestone underneath formed from sea creatures that lived in the ocean that covered the area about 350 million years ago, according to Burren National Park.

Glaciers

• Glaciers during the ice age scraped away much loose material in the pavement areas and deposited piles of loose material in the forms of drumlins and moraines or low ridges, according to Burren National Park. The glaciers moved and deposited large limestone boulers on top of the limestone pavement. Burren National Park suspects the exposed limestone pavement habitat featured in the Burren formed from a combination of scraping away of rocks by glaciers, soil erosion caused by runoff from melting glaciers and removal of woodland for farming.

Water and Wind Erosion

• Limestone is a water-soluble rock, and rainwater caused formation of features of the Burren through erosion in a number of ways. According to Ireland Midwest, erosion results from a chemical weathering process known as carbonation. With carbonation, rain absorbs carbon dioxide from the atmosphere, which forms carbonic acid that reacts with the calcium carbonate in the limestone, creating cracks and crevices. Acid rain caused fissures called grykes to form in the flat slabs known as clints. Strong winds carrying salt water from the Atlantic Ocean into the Burren leads to the development of much of the vegetation.

Caves and Underground Rivers

• According to Dochara.com, as water reached harder rock beneath the soluble limestone it was forced sideways, forming subterranean caves and caverns. The carbonation process worked below the ground to form stalactites and stalagmites in the caves. The roofs of some caverns collapsed, leaving depressions known as turloughs that filled with water during winter, forming shallow underground lakes. In other areas, the water formed underground rivers as it was forced sideways. The Burren also contains shallow swallow holes, or sink holes, which are openings in the bed of a river that flowed over limestone to follow an underground course.