Upper Lathkill Dale near Monyash, Derbyshire

Originally uploaded for the Guesswhere UK group.

View north west looking towards the B5055 (on the far side of the stone wall running from right to centre). Monyash village is just out of sight beyond the trees on the centre skyline.

The valley is asymmetrical in cross-section at this point (and at number of other locations along its length). The steeper and rocky north-facing slope - on the left in this photo contrasts with the more gentle southward facing-slope. This is interpreted as a periglacial effect dating from the last glacial period (the Devensian) when the Peak District was largely free of ice, yet subject to intense cold. The north-facing slope would have been largely in shade for much of the year, remaining frozen. The permafrost on the south-facing slope would have partially melted during the summer months, allowing solifluction/gelifluction processes to transport material into the valley bottom, blurring out the rock features.

Lathkill Dale itself is thought to have originated, at least in part, as a tunnel valley: erosion by a sub-glacial meltwater channel during pre-Devensian glaciations when the Peak District was covered by ice.