THE GLACIAL GEOLOGY OF NORTHUMBERLAND IO9 



(700 feet), and Screnwood E 7 (550 feet). The last two are 

 enormous valleys, their eroding waters being fed from the 

 Biddlestone Burn, through E 8 (1,100 feet) and E9 (1,000 

 feet), and through the great series E 10 to E 15 (950, 930, 900, 

 800, 700, and 680 feet) on Harden and Ewe Hills. (Photo- 

 graphs 6 and 7.) Many of the last are marginal trenches, 

 and indicate that the ice-edge lay parallel to the direction of 

 the Harden Hill ridge. E 10 is marginal in the western part 

 of its course, then it crosses the water-parting, making a very 

 conspicuous gap in the sky-line, and falls abruptly on the 

 north side of the hill (Photograph 7). 



The occurrence of a small but well-cut swire (E 16) and 

 several marginal trenches on the right bank and near the foot 

 of the Barrow Burn ( Alwinton) may indicate a further stage in 

 the retreat of the western ice. 



Near the head of the Coquet there is evidence, both from 

 striations and the transport of boulders, of ice-movement from 

 the north and west; and the occurrence of three swires, 

 apparently belonging to the same series, points to a general 

 movement from the north-west at the close of glacial con- 

 ditions. The first is Graham's Cleugh, Fi (1,320 feet), con- 

 necting the Philip with the Ridlees Burn; the second F2 

 (1,300 feet) cuts the ridge between the Gable and the Deer- 

 bush Burns; and the third F 3 (1,250 feet) notches the water- 

 parting between the Trows and Barrow Burns. This series 

 possibly marks the flow of Tweed ice across the Border, and 

 this is further indicated by two isolated gashes, viz., between 

 Broadhope Hill and Scald Hill at 1,500 feet, and between 

 Windy Gyle and Mozie Law at 1,600 feet. Both of these 

 require a flow of ice from the Scottish side of the Border to 

 account for their position. 



Summary. 



The glacial period in Northumberland resolves itself into a 

 struggle between (1) local ice-flows, especially those from the 

 Cheviots and the Carter Fell district, (2) a great sheet impelled 

 from the west, across the Cumberland border and down 



