NORTH-WEST OF ENGLAND AND NORTH WALES. 99 



Widnes, near the mouth of the river Weaver, which, with its tribu- 

 taries, is almost confined to the Keuper marls. 



The extremely fine unctuous nature of the clay down to a depth 

 of 140 feet from the surface, together with the position of the 

 deposit, points most conclusively to the river "Weaver as the origin 

 of it. None the less clear to my mind is it that the whole of 

 the Boulder-clay, as seen in the cliffs on either side of the river 

 Mersey, from Runcorn to its mouth, and the fine clay in the North 

 Docks, have a similar origin. 



The plateau of Keuper mark also appears to have provided the 

 matrix of the Boulder-clay along the valley of the Mersey up to 

 Manchester. When we get to Stockport we are in the region of 

 sands and gravels, as is also the case at Hazel Grove. Here the 

 drainage is from the steep hills of Carboniferous sandstone ; there- 

 fore it is a natural and fair inference that the character of the Drift 

 has changed from this cause. 



At Macclesfield we again come onto the Boulder-clay and over- 

 lying sands and gravels ; and as that town is situated at the foot of 

 steep hills of Carboniferous sandstones on tl.e one hand, and the 

 Keuper-marl plateau on the other, we are led to conclude that the 

 sands have come from the one, the clays from the other. The 

 northern side of the Mersey is occupied with Triassic rocks ; and 

 beyond lie the Coal-measures. 



May not these have supplied the material for the included beds of 

 sand found in the Boulder-clay ? At Upton, in Cheshire, the drift 

 again changes ; but here we are getting very close to the drainage 

 of the river Dee, which is largely fed from a sandstone area ; so 

 now I will proceed to examine the drift found in the basin of the 

 river Dee. 



Driet oe the Basin of the Elver Dee. 



From West Kirby to Parkgate, on the east bank of the estuary of 

 the Dee, is a cliff of Boulder-clay which has attracted some atten- 

 tion. The section at Dawpool has been described by Mr. Mackin- 

 tosh in the Quarterly Journal of the Geological Society, vol. xxviii. 

 pp. 388-392, and vol. xxxiii. pp. 731, 732. Nearer to Hoylake the 

 cliff is lower, and overlain by blown sand. Between the blown 

 sand and the Boulder-clay is a bed of Postglacial blue silt or clay, 

 1 foot 9 inches thick and 4 feet 6 inches above high-water level ; 

 further up the estuary this bed rises to 9 feet above the same level, 

 with a thin bed of soil under it, and then sand lying on the Boulder- 

 clay. 



The highest level of these Postglacial beds noticed by me is from 

 12 to 14 feet above high- water. They consist of blue clay con- 

 taining a few pebbles underlain by yellow sand resting upon the 

 Boulder-clay. The Boulder-clay is of a deep purple colour. As you 

 « approach Dawpool the cliff becomes loftier, and has in it a thin bed 

 of intercalated sand and gravel. Further on, again, the cliff was of 

 homogeneous Boulder-clay. 



I have examined these cliffs at various times ; but the sections 

 Q.J.G.S. No. 154. i 



