Limestone in the Dales

It has taken millions years for the distinctive character of the Yorkshire Dales to develop into the fantastic landscape we see today

Rock, ice, rain and man have all had a great influence on the land. This began with the carboniferous period three million years ago when the remains of small shells and skeletons of animals where deposited at the bottom of a shallow, tropical sea, then compressed to form layers of sedimentary rock, which can be up to 200 meters thick in places. These layers of limestone where then folded and faulted by the forces of nature.

The last ice age gave a new shape to the dales. Glaciers scraped away the surface exposing the natural joints in the underlying limestone rock. Slightly acidic rain dissolved these vertical joints creating the limestone Clints and Grikes (blocks and the crevices in between), which comprise the limestone pavements.

Water erosion from the receding glaciers has created an underground labyrinth of limestone caverns, caves and potholes. River and streams often disappear underground leaving dry river beds, then reappear again much further away where the limestone layer changes to shale and gritstone forcing the water back to the surface. Water is also responsible for another common feature of classic limestone country, the depressions in the land known as shake holes or sinkholes. These are formed when surface water washes the surface boulder clay down into the cracks and fissures in the limestone underneath, or by the collapse of a limestone cave.

Hundreds of years of farming and land management in the dales has since developed the limestone landscape into the characteristic pattern of fields enclosed by dry-stone walls, with field barns scattered amongst them.

The Yorkshire limestone areas are a unique and irreplaceable resource that is now the focus of conservation.
Around 1% of the land contained within the Yorkshire Dales National Park is limestone and this accounts for over 50% of all that is found in the UK. Many of the pavements and other Yorkshire Dales limestone areas are designated Sites of Special Scientific Interest (SSSI's).