DAKYNS : GLACIAL PHENOMENA OF WHARFEDALE. 
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contains subangular blocks of Millstone Grit about 3 feet in dia- 
meter. This gravel continues some way up stream. 
Opposite Lud Stream Islands there is a gravel in a similar posi- 
tion and apparently of a similar character, but the section is not 
clean cut. It is surmounted by another bank of gravel (section also 
not good) apparently of the same general character, but containing- 
much larger subangular blocks of grit. The top of this gravel bank 
is 75 feet above the river, and from its edge there stretches a gently 
rising and undulating surface for about one sixth of a mile to the foot 
of the hill called South Nab. This plateau may be entirely of gravel. 
On the left bank of Posforth Beck, a little below the first bend 
in the stream above its junction with the Wharfe, there is a section 
in true glacial drift. The material consists of angular debris of grits 
and limestones, and the blocks of the latter are well glaciated. It 
contains also fine stratified sand, beautifully false-bedded. The 
boulder-bearing drift seems to wrap round the sand, but the section 
is not clear. Further down stream there is a similar angular deposit. 
There are plenty of rounded stones ; but the characteristic feature is 
angularity. 
Pickles Gill, above its junction with Tom Taylor Dike, is full of 
drift, consisting of angular blocks and pebbles of grit and limestone. 
The pebbies are mostly of limestone ; and the limestones are glaciated 
and scratched, particularly the pebbles 
It is not necessary to give any more details of section?, as it 
would merely be a repetition of what has been already said. The 
general result is that the boulder beds vary from a true boulder clay 
to a stony mass, which consists sometimes of a heap of angular frag- 
ments, while at others it contains a large number of pebbles ; and 
that in the latter case, on the Millstone Grit area in the south, the 
larger proportion of the pebbles are of limestone, and that the lime- 
stones are generally scratched, the grits but rarely so. Evidently 
the reason why most of the pebbles are of limestone is that the lime- 
stones have come the greater distance. 
Further, the true glacial boulder beds are mixed up with finely 
stratified sand and gravel. Lastly, well water-worn gravels, 
containing large boulders and angular blocks, line the valley sides 
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