Deeply-incised parallel runnels in a limestone pavement
Deeply incised, densely-packed parallel drainage runnels in an inclined limestone pavement at Holme Park Fell, South Cumbria. The runnels dissect the clints at right angles to the grikes.
Limestone pavements were formed during the last Ice Age in the Pleistocene period when moving glaciers scoured bare the surface of the underlying limestone bedrock. The classic pattern of clints (blocks) and grikes (fissures) was produced by the erosive action of overlying soil - such as the moraine deposited by the glacier - and the rainwater that permeated it, enlarging the natural faults in the limestone rock.
(One of a sequence of 9 images in this gallery).
Date taken: 24 September 2014.