Karst Landscape - Limestone (i) Name the category of rock in which limestone belongs - Junior Cycle Geography - Question A - 2011

One prominent location where limestone is found is the Cliffs of Moher in Ireland. This area showcases spectacular limestone formations and is renowned for its scenic beauty.

Karst underground landforms, such as caves, are formed through the process of chemical weathering and erosion. When acidic rainwater seeps through soil and into limestone bedrock, it reacts with the calcium carbonate to dissolve it, creating underground voids. Over time, these voids can expand to form extensive cave systems.

The formation process includes two main steps:

1. Dissolution: Rainwater, which absorbs carbon dioxide from the atmosphere and soil, forms a weak carbonic acid that starts to dissolve limestone. This reaction can be represented as:

   $CaCO₃ + H₂CO₃ \rightarrow Ca^{2+} + 2HCO₃^{-}$

2. Erosion: Continuous flow of water through these voids can carry away dissolved limestone, further expanding the cavernous spaces.

A simple diagram would show water flowing into a subterranean limestone layer, dissolving it and forming caverns over time.