BETWEEN THE TYNE AND THE WANSBECK I03 



position to survey, in a more detailed manner than has 

 hitherto been possible, the past history of this tract of country 

 from the times immediately preceding the Great Ice Age to 

 the present. 



Before the coming of the ice the surface of the land was 

 graven by a number of streams which flowed roughly down 

 the dip-slope of the rocks. Of these the chief were the 

 " Pont "' and the " Blyth," which, uniting west of Blagdon, were 

 turned northwards along the escarpment of the Coal Measures 

 and entered the " Sleekburn " somewhere near Hepscott ; and 

 the "Ouseburn" which, rising near Heddon Mill, followed a 

 course very similar to that of its modern representative. 



During the Glacial Period the land was covered with an 

 enormous ice-sheet which moved on the whole towards the 

 east and south-east, bringing with it a vast quantity of loose 

 talus matter and mud, and which on melting deposited its 

 burden irregularly over the land, in some cases completely 

 blocking the valleys of the ancient streams. Before the 

 passing of the ice completely, the high land west of the 400-feet 

 contour became relatively free from ice, while the country east 

 of this was held by a sheet which moved in a general southerly 

 direction. The new streams developed on the higher land 

 were barred by this ice-sheet, extensive lakes were thus 

 formed which overflowed across the natural watersheds, and 

 as the sheet gradually retreated the level of the lakes fell, with 

 the result that fresh notches at progressively lower levels were 

 cut by their outflowing waters. When finally the ice dis- 

 appeared, these overflow channels were left high and dry, and 

 the normal streams accommodating themselves to the now- 

 altered contour, were forced to carve new passages, often 

 forsaking the courses of the pre-glacial valleys and cutting 

 through what were lofty watersheds in pre-glacial times. Thus 

 the Blyth has cut the gorge of Stannington Vale, and the 

 Ouseburn that of Jesmond Dene, since the ice passed away; 

 and on the other hand three deep pre-glacial valleys running 

 respectively north through Stannington, north through Horton 



