Water reappears outside the cliff as a resurgent stream
Fig. 5 Surface and underground features in limestone areas Limestone pavement
This is the name given to the surface of bare limestone rock, e.g. the Burren, County Clare. The formation of limestone pavements began with the scouring
of the limestone by thick glaciers during the last Ice Age. The weight of the ice removed the soil that lay over the limestone, leaving level platforms of limestone. Then a thick layer of boulder clay (glacial till) was deposited as the glaciers retreated. As rainwater seeped into the soil it became even more acidic as
it absorbed organic acids from decaying vegetation. This acidic water easily dissolved vertical lines of weakness (joints) in the rock. The carbonation process widened and deepened the many
fissures, which are then termed grikes. Flat surfaces of rock a few square metres in area exist between the grikes. These are called clints. Gradually the soil on top of the limestone pavement
disappeared down the grikes and was washed deep underground. Today we see this exposed limestone pavement in many areas of Ireland and Europe. The entire rock surface looks like crazy paving slabs. Grikes
provide much-needed shelter for plants and animals in an otherwise barren landscape. In the Burren area the soil was washed away sometime in the
late Bronze Age, roughly 3,000 years ago when the climate deteriorated. The area was cleared of forest and intensely farmed. Without tree roots to bind the soil together it was easily removed by the rain.