KENDALL : THE (iLACIEli LAKES OF CLEVELAND. 
31 
retreat of the ice-front threw the central and southern lakes into 
confluence, and as the Blacksmith Hill outlet was well below 
the intake of Evan Howe Slack, it took the whole drainage. 
When this happened, the ice stood for a short time against 
Swallow Head, the spur whicli bounded Kirk Moor Lake, for an 
overflow across the spur at ^loor Close Plantation cuts at its 
lower end below the Evan Howe Slack intake. 
A final recession of the ice opened a way for the waters round 
the seaward end of Peak, and, perliaps. by channels cut in the 
lower grounds, of which marine denudation has left no relic. 
During the whole of the period of the prevalence of these lakes 
it is probable that water was flowing out of Iburndale by way 
of Biller Howe Dale. Xo lower escape for the drainage of that 
valley, or of the outer face of the Sneaton Moors, existed, or 
could have existed, without leaving unmistakable traces. A fine 
example of a deserted oxbow runs behind Brown Rigg (Plate 
XI.), a bold hill dissected out of the moorland on the east side 
of Jugger Howe Beck. This oxbow channel is cut to a depth 
of from 60 to 70 feet, and is about half a mile in length. At botli 
ends it opens out on to the precipitous wall of the Jugger Howe 
Valle}', about 60 feet above its floor. 
Harwood Dale Lake. — At the period of maximum extension 
the ice reached the edge of what is now Jugger Howe Beck. 
Before the Robin Hood's Bay \Aatershed was breached Helwitli 
Valley descended nearly to its present junction with Jugger 
Howe Beck, but the continuation of its course was what is now 
known as Castle Beck into Harwood Dale (Plate XII.). 
When the ice advanced over this country it thrust across 
Castle Beck, diverting the drainage into a marginal channel, 
along which also poured the overflow from the Robin Hood's 
Bay area, and so a deep gorge was produced. A range of gravelly 
moraine now extends along the verge of Jugger Howe Beck, 
whose deep, narrow channel contrasts very strikingly with the 
broad, open valley of Castle Beck (Fig. 9). beside which it runs. 
The course of Helwith and Jugger Howe Becks, if produced, 
follows the line of the great valley of West and East Syme. 
which extends from Harwood Dale to Burniston. This im- 
portant valley is now occupied only by two diminutive streams 
