River Twiss Valley
The idea of an inlier is shown in the photograph. The Twiss Valley exposes the oldest rocks, the Lower Palaeozoics, while the Carboniferous limestones are clearly seen exposed on higher ground.
Of particular interest in the photograph of Kingsdale Valley is the Raven Ray End Moraine. This is a product of events related to the last ice age which had a major impact on shaping the valleys. The ice age was characterised by the repeated advance and retreat of ice sheets across the Yorkshire Dales. The Raven Ray glacial moraine had two major effects:
a) It held back meltwater thus creating a Lake Kingsdale.
b) The moraine diverted the River Twiss away from its original course.
On crossing the valley to the River Doe section try to spot ‘Tiddemans Breccia’. Tiddeman (along with McKhughes and Gunn) in 1870 did the first comprehensive study of the geology of Ingleton. The breccia is seen in one of a few isolated rocks in the farmer’s field. The coarse clasts in the limestone boulder are partially angular and rounded. This is evidence for the local unconformity of Dinantian limestone and Ingletonians in Chapel Le Dale. This extra locality allowed the party the chance to view Ingleborough and Skirwith Quarry. The geology of Ingleborough itself was explained as this extends into the famous Yoredale Cycles. Also the vast workings of the quarry could be seen and the term ‘Ingleton Granite’ was explained to the party.
It's also a good idea to make a note of the plant life that you encounter on your walk. Often the kind of plants you see reflect the underlying geology. In this case, in late April 2004 the Wood Anemone was in full flower. This is a member of the buttercup family. It is usually found in mixed deciduous woods often near damp calcareous soil.