268 



GL4CIAL PHENOMENA IN THE NEIGHBOURHOOD 

 OF GUISBROUGH. 



FRANK ELGEK, 

 Mitldlcshorough. 



In view of the forthcoming- meeting of the ^'orkshire Naturalists' 

 Union at Guisbrough in August, it may be of interest to give a 

 few notes on the Glacial Geology of the Guisbrough \'alley, 

 more especially as some of the phenomena have not hitherto 

 been described. 



Professor P. F. Kendall in his great paper, ' A System of 

 Glacier Lakes in the Cleveland Hills,' has shown that a glacier 

 from the Cheviots swept down upon the Cleveland area, and in 

 his opinion it coincided with a period of maximum glaciation 

 from Scarth Nick to the Wykeham Moraine.* Consequently it 

 would impinge directly upon the great Jurassic escarpment 

 bounding the Guisbrough Valley to the south. At Bold 

 Venture, at 800 feet, occur gravel mounds with Cheviot 

 Porphyrites indicating a glacier lake overflow down Sleddale.t 

 Erratics are even to be found on Newton Moor at a height 

 of 1000 feet. 



When the ice began to retreat, a small lake was held up 

 in High Bonsdale, the overflow falling westward at 675 feet. [ 

 As the ice melted backwards a great overflow out of the 

 Boosbeck Valley into the Guisbrough Valle}' was initiated, 

 forming the Slapewath Gorge (600-425). 



Professor Kendall § thinks that, as no channels exist along 

 the western slopes of the hills in alignment with Slapewath, 

 Airy Hill, above Skelton, acted as a barrier to the ice, and 

 that a sinuous lake extended along the hill sides. However 

 this m%>- be, at the foot of Bonsdale Hill is a great bank of 

 drift (Grove Hill) 400 feet high, with a fine wcs/erly channel in 

 front of it, cutting at its exit near Lowcross House, the 325 

 foot contour. I do not think that this \alley was in alignment 

 with the Slapewath overflow. It simply seems to have been 

 produced at a later stage of retreat when the waters in the 

 Bonsdale Valley escaped round the end of the hill. The channel 

 is of a type not uncommon along the steep slopes of the Jiwassic 



* OiKir/trly Joiiniiil (ifolii^ictil Soiic/y, X'ol. 5S, p. 505. 



t Op. at. p. 519. 



X Kendal, Op. rit. p. 510. 



§ ' ProccctliiiLTs ^'l>|•kshi|•o ( leoldifioal .Sorittx',' 1903, p. 44. 



Naturalist, 



