Explain, with the aid of a labelled diagram, how any one underground feature in a Karst landscape was formed. - Junior Cycle Geography - Question B - 2011

The diagram should include a sinkhole with labels indicating:

• Surface Layer
• Underground Water Flow
• Dissolution of bedrock

(Ensure the diagram accurately represents the feature with clear labeling.)

Sinkholes form primarily through a process called dissolution. When rainwater, which is slightly acidic due to dissolved carbon dioxide, seeps into the ground, it begins to leach away the soluble bedrock, typically limestone. This process gradually enlarges existing fractures and voids in the rock.

Over time, as more limestone is dissolved, a cavity is created underground. If the roof of this cavity becomes too weak or thin to support the weight of the overlying material, it can collapse, resulting in the formation of a sinkhole.

Thus, the combination of chemical weathering through dissolution and structural failure contributes to the development of sinkholes in Karst landscapes.