Rocks are continually formed and changed by forces within the Earth.

There are three rock types: Igneous, Sedimentary and Metamorphic.

The rock type I have chosen is: limestone, a sedimentary rock.

Limestone can be found in Ireland in the Burren, Co. Clare

Limestone is an organic sedimentary rock composed almost entirely of calcium carbonate

Limestone is formed from the billions of skeleton remains of marine creatures such as fish, sea urchins and coral.

Over time these creatures were compressed by their own weight and cemented to form solid rock.

In Ireland’s case, this took place 350 mya, when the country was approximately 30?South of the Equator in a tropical location.

There are many types of limestone, including carboniferous, dolomite and chalk.

It is a stratified rock, laid down in horizontal layers (strata) which are divided by bedding planes. Vertical cracks and joints also occur in limestone.

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Limestone is a permeable rock, which means that water can seep through it due to its joints and bedding planes.

Limestone is therefore vulnerable to the chemical weathering process of carbonation, caused by carbonic acid dissolving the cementing agent (calcite) of the limestone.

The calcite will be dissolved into a solution caused calcium bicarbonate.

If limestone is subjected to intense heat, it changes to the igneous rock, marble.