Ingleborough from White Scars limestone pavement, with glacial erratic boulders
Ingleborough mountain (one of the 'Three Peaks'), from the limestone pavement of White Scars, with glacial erratic boulders of greywacke (Millstone grit) in the foreground.
Glacial erratic boulders were transported sometimes great distances by a glacier and deposited on top of the very different local rock as the ice sheet started to melt. As such, they stand out as alien to the surrounding landscape and they serve as reminders of the sheer power of glaciers.
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.
In White Scars, the high level of erosion of the thin, platy Yoredale Group limestone caused by long-term burial under soil permeated by rainwater has led to some fantastical shapes and very visible layering.
Date taken: 02 May 2013.