Vol. 58. ] GLACIER-LAKES IN THE CLEVELAND HILLS. 537 
were encountered, namely at Hackness and Suffield Moors. It will 
be further shown that at these two places the physical features of 
the country were such as to secure a stable position of the overflows 
during considerable oscillations of the ice-front, so that persistent 
cutting on one line of overflow would take place, instead of the exca- 
vation of a parallel series of successive channels such as occurred in 
many areas. 
I shall deal with this region in four sections, corresponding with 
four natural divisions of the country :—(a) Robin Hood’s Bay ; (6) 
Peak to Cloughton, and Hellwath to Harwood Dale and Burniston ; 
(c) Burniston to Scalby ; and (d) Scalby to Filey. 
(a) Robin Hood’s Bay. 
Physically, Robin Hood’s Bay is the half of a dome-like inlier of 
Lias produced by a cross-fold at the seaward end of the Cleveland 
anticline. 2 
The various divisions of the Lias, down to the planorbis-zone, are 
exposed round the shores of ,the bay ; above these come the Lower 
Oolites, consisting mainly of the Lower Estuarine Series, a succession 
of sandstone, shales, and coals presenting a surprising resemblance 
to the Coal- Measures. 
The bay is surrounded by a much deeper amphitheatre of high 
ground composed of the Lower Estuarine Grits, which form a bold, 
and in places precipitous, escarpment recessed by several alcoves, 
where streams come, or came down into the bay from the surround- 
ing moorlands. The interior bay is packed with Boulder-Clay to 
so great an extent, that very few rock-exposures are to be found even 
in the deeply-cut ravines, and at least at one place, at the mouth 
of Stoup Beck, the Drift-deposits extend below the beach-level. 
An outer fringe of Drift near Kirk-Moor Gate and Latter-Gate 
Hills consists of sand and gravel heaped up in large mounds. 
The pre-Glacial watershed has, in part, been already defined, being 
on the north-west and north that of Iburndale and Sneaton Low 
Moor. ‘To the south and south-east, it extended from Peak through 
Stony-Marl Howes, and thence in a wide sweep, round by Burn Howe 
and Blea-Hill Rigg, to John-Cross Rigg above Iburndale. The 
drainage of the whole of this area probably converged on Robin 
Hood’s Bay, as that of the northern segment still does, and the 
gradients down to the edge of the grit-escarpment were in the main 
so low as to produce rather the appearance of a plateau than of a 
ridge. (See map, Pl. XXVI.) 
At the period of maximum extension, the margin of the ice-sheet 
appears to have extended from the head of Iburndale along a west- 
to-east line to the great bend of Biller-Howe Dale, and thence to 
have run in a southerly direction past the side of Biller-Howe farm- 
house, and on to the junction of alittle nameless beck, south of ‘ the 
Island,’ with Jugger-Howe Beck. The margin is well defined along 
the whole line by the extension of the Drift and pebbles, and by the 
