Carbonation and karst landscapes Learning Intentions
In this section, you will learn: zzwhere carbonation occurs in Ireland and how it has created a unique landscape
zzhow surface and underground features form in a karst landscape
zzthe positive and negative impacts of tourism in a karst landscape.
Carbonation occurs in areas where bare limestone rock is exposed to the weather. These areas are known as karst landscapes.
An example of a karst landscape in Ireland is the Burren in Co. Clare. The soil was removed from the Burren by ice-sheets during the last ice age. This left the bare limestone rock exposed. Carbonation has created a unique landscape in the region. We will now look at the features that have formed both on the surface and underground because of carbonation.
Surface features
Limestone pavement The surface of a karst landscape is called a limestone pavement. This is how a limestone pavement is formed:
• Rainwater falls onto the exposed limestone and passes through vertical joints or cracks in the limestone.
Karst
Limestone pavement Joint Grike Clint
Swallow hole Bedding plane
Hydraulic action Cavern
Stalactite Calcite
Stalagmite
: Figure 6.6 A view of the Burren, Co. Clare
DID YOU KNOW? Karst landscapes are named after a limestone region called Karst in Slovenia.
Joints: the long vertical cracks in limestone rock.
• Carbonation makes the joints wider by dissolving the calcium carbonate in the limestone until they then look like grooves or gaps in the limestone. These grooves or gaps are called grikes. • The blocks left in between the grikes are called clints.
Grike Clint
Joint : Figure 6.7 Limestone pavement in the Burren, Co. Clare 92 : Figure 6.8 Features of a limestone pavement
