ELGEE : GLACIATIOX OF NORTH CLEVELAND. 
381 
forms — GryvhcEa arcuata. Ammonites angulalus, and an indeter- 
minable Pecten. They seem to show that the Cheviot ice moved 
in a soutli- westerly direction on to the Cleveland Hills at the 
western end. 
At Newby and to the north as far as Marton and ToUesby, 
the surface is covered with Boulder Clay, which often assumes 
the form of ridges and mounds, though not on such a striking 
scale as those just described. In the stream sides a bed of sand 
occurs in the clay, dividing it into two layers, and near Marton 
I have found in it striated Magnesian Limestone, Lower Lias 
fossils and clay ironstone concretions. I do not think that 
these sands can be correlated with those near Seamer, since 
the latter have no Boulder Clay above them. The so-called 
Upper Boulder Clay terminates in a long ridge running from 
Marton towards Stainton, with a long strip of sand and gravel 
running along its slopes as far as the village of Eston. 
Probably during the deposition of the Stokesley moraines 
Ihe dry channels on Eston Hill (described in a paper to " The 
Naturalist," August, 1906) were being eroded, since both features 
indicate the last considerable halt of the ice in North Cleveland. 
The ice front would by no means be straight, owing to 
the form it would assume after contact with the great 
embay ment of the Jurassic escarpment at Greenhow Botton. 
The drainage from Scugdale Slack, on the Eston outlier (Plate 
LII.), swept round to the south-westwards along the Guisborough 
Valley, and a shallow channel can be traced as far as the 
Langbaurgh overflow. It seems probable that though some of 
the waters escaped through the gap, the rest simply spread 
over the drift-covered floor. 
The results obtained by this survey of the glaciation of 
North Cleveland may now be summarised as follows : — 
L — The period of maximum extension when the Bold 
Venture moraine and drift pebbles at 1,000 feet on Newton 
Mooi vv^ere deposited, and Holy Well Gill was eroded. 
(Kendall.) 
2. — Period when Gribdale Gate, the Bilsdale overilow» 
and Scarth Nick were in operation. (Kendall.) 
I 
