Professor J. W. Gregory — Tlie EnglisJi '' Eshcrs". 81 



deposits near the margin of a retreating glacier, and may therefore 

 be regarded as fluvioglacial kames. 



2. Reported High Level Eslers — the Lanshaw Delves. — Of the 

 high-level " eskers " of this part of Yorkshire, the most often 

 mentioned has been the Jjanshaw Delves, which is situated on the 

 N.E. slope of Rombald's Moor, l\ miles S.S.E. from Ilklev, at the 

 level of about 1,180-1,200 feet on" the S. side of the Wharfe Valley. 

 It is a bank about 650 yards long, 25 yards wide at the W. end, 

 and 50 yards wide at the E. end ; the height is 8 feet at the W., 

 and 15 feet at the E. end ; the trend is a little S. of E. ; the S. 

 front is the straighter and higher. The summit of the Delves is 

 irregular and hummocky, the depressions sometimes giving it the 

 character of a triple ridge. It has been referred to as a high level 

 esker by Green.^ Carvill Lewis has given the best account of it.^ 

 He described it as moraine, and regarded it as part of a long lateral 

 moraine. It consists of saady loam, with many angular blocks of 

 Millstone Grit similar to those strewn over the adjacent moor. 

 Some of the boulders are 4 feet in diameter ; many are 2 feet long. 

 They are irregular in shape, and none shows glaciated forms or striae. 

 The smaller pebbles include vein quartz, and jagged fragments of 

 black chert ; and all of these may have been derived from the 

 Millstone Grit. A few well-rounded cobbles may have beeii derived 

 from a local stream. The occurrence of angular flakes of grit, 

 some of them many square inches in area and a quarter of an inch 

 thick, show that the material was not transported by rivers or these 

 pieces must have been broken. The boulders are sometimes crowded 

 in piles, but they show no arrangement in bands across the Delves. 

 The bank shows no signs of formation as an ordinary aqueous or 

 fluvioglacial deposit. It is a morainic bank formed along the 

 margin of a sheet of snow and ice that filled the depression in 

 which lies Lanshaw Dam. The moor rises to the height of 1,320 

 further W., and to 1,250 feet at 800 yards S. of the Delves. The 

 depression between the summit and the Delves faced N.E. and was 

 probably filled with a sheet of snow and ice. The local blocks of 

 Millstone Grit were carried to its edge, but the movement was 

 insufficient to give them glaciated forms or striae. The Delves 

 are the remains of a moraine on the margin of an embryo corrie 

 glacier. 



According to Green the Delves can be traced for three miles 

 across the moor. Some coarse gravel occurs further E., a little 

 S. of the farm known as Gaping Goose on Hawkshaw Moor ; but 

 I saw no evidence of its continuity with the Delves. Carvill Lewis 

 (op. cit., p. 243) records information from some shepherds about 

 structures known as the " Great and Little SkirtfuU of Stones " and 

 " Long Ridging ", which he suggested might be similar in origin. 



1 Geol. Yorks. Coalfield, 1878, p. 779 ; Meyn. Geol. Surv.,^-1 S.E., 1879, p. li'. 



2 Loc. cit., 1894, pp. 34, 243. It has been identified as a prehistoric 

 earthwork. 



