Jackson, Ian. Cumbria Rocks — 60 extraordinary rocky places that tell the story of the Cumbrian landscape. Newcastle upon Tyne : Northern Heritage, 2022.
The richly illustrated and accessible book series of Cumbria, Northumberland and Durham Rocks are available to purchase from Northern Heritage.
Theme: Climate and landscape change
43 Skelsmergh — drumlins. Less than 3 kilometres drive north on the A6 from Kendal
Just north of Kendal the A6 weaves through a collection of whaleback mounds. They are called drumlins.
On the lower ground of Cumbria overlooked by the mountains of the Lake District and the Pennines, drumlins are everywhere. Images from space show the vales and plains filled with what look like thousands of giant half-buried eggs. They are all aligned, and they appear to ‘flow’. Drumlins are a rich area of study for geologists but exactly how and when they formed remains a mystery. All agree they formed under an ice sheet and that they show the direction of ice flow, but beyond that their origin is a debate that has rolled on for decades. The widely accepted theory is that ice sheets ride over and deform a whole variety of glacial debris beneath them and streamline it. But until someone is able to watch a drumlin form underneath an ice sheet, exactly how they are constructed remains theoretical! Drumlins and other glacial features have been used to try to work out how and when ice sheets moved across Cumbria. Satellite images, aerial photography and recently radar and laser technology (bouncing beams from a plane to the ground to precisely measure the surface height) have helped scientists enormously. That research confirms that the Lake District had its own ice cap and also suggests that ice sheets flowing from there, the Irish Sea, and the Vale of Eden have come together and, at times, completely switched direction. The result is drumlins overprinted on drumlins; 20,000 years ago the Cumbrian lowlands were a real mixing bowl.
Our undulating landscape is one piece of evidence of the Ice Age, another is well known to many gardeners across Cumbria: boulder clay (geologists now call it till or diamict). The mud, sand and stones that were once on, in, beneath and churned up by the ice are now the sticky, stony clay that makes digging such hard work.