We have thus an accredited explanation for the extraordinary behaviour of
the river Derwent and its tributaries, including practically the whole of
the drainage south of the Esk, which instead of taking the obviously
simple and direct course to the sea, flow in the opposite direction to the
slope of the rocks and the grain of the country. After passing through the
ravine at Kirkham Abbey the stream eventually mingles with the Ouse, and
thus finds its way to the Humber.

The splendid cañon to the north of Pickering, known as Newton Dale, with
its precipitous sides rising to a height of 300 or even 400 feet, must
have assumed its present proportions principally during the glacial period
when it formed an overflow valley from a lake held up by ice in the
neighbourhood of Fen Bogs and Eller Beck. This great gorge is tenanted at
the present time by Pickering Beck, an exceedingly small stream, which now
carries off all the surface drainage and must therefore be only remotely
related to its great precursor that carved this enormous trench out of the
limestone tableland. Compared to the torrential rushes of water carrying
along huge quantities of gravel and boulders that must have flowed from
the lake at the upper end, Newton Dale can almost be considered a dry and
abandoned valley.

[Illustration: A Diagrammatic View of Newton Dale during the Lesser Ice
Age. The overflow of the glacier dammed lakes at the head of the dale came
down Newton Dale and poured into Lake Pickering.]

At Fen Bogs, where there is a great depth of peat, Professor Kendall has
discovered that if it were cleared out, "the channel through the watershed
would appear as a clean cut, 75 feet deep." The results of the gouging
operations of this glacier stream are further in evidence where the valley
enters the Vale of Pickering, for at that point a great delta was formed.