The Burren Co. Clare
Formed during the Carboniferous Geological Period 350 million years ago.
Skeletons of marine life, corals and sea-shells were deposited in strata or layers
called bedding plains on the bed of a tropical sea.
The remains were compressed by the weight of the overlying deposits and the
weight of the sea.
Calcium Carbonate from the bones of the decayed marine life cemented the
deposits into limestone.
During the Armorican Mountain building period the sedimentary rocks were
uplifted and fractured to form joints.
The Burren has very little surface drainage as limestone is permeable. However
the Caher River in the NW flows over impermeable till(boulder clay) deposited
by glaciers during the last ice age and so runs along the surface.
The Burren was covered in forests but this was easily removed by early settlers
and led to soil erosion.
Weathering in a Limestone area
Rainwater falling through the atmosphere absorbs CO2 forming carbonic acid
which reacts with calcium carbonate(the cementing agent in limestone) to
produce a soluble calcium bicarbonate which is carried away in solution. This
process is called Carbonation.