C. E. Be Bance — Surface Geology of the Lake-district. 493 



Mackintosh, in his paper on the " North-west Lancashire Drifts," read 

 before the Geological Society on June 23rd of this year. 



In the Manchester district, described by Mr, Hull, the upper and 

 lower clays are identical in character ; they are both of a reddish 

 colour, contain rounded and sub-angular pebbles and boulders, which 

 appear to have been thrown down from icebergs in a Glacial sea, 

 rather than by an ice sheet. The lower Boulder-clay is stated by 

 Mr, Hull never to make its appearance in the hill country, and the 

 Middle Drift, which rests on the denuded surface of the lower TiU, 

 in the low country, is found resting on the bare rock in the upland 

 valleys of south-east Lancashire, and the bordering parts of Cheshire.^ 

 In one locality near Macclesfield, in an escarpment half-a-mile east 

 of the Little Dog Inn, on the Buxton-road, Mr. Prestwich, F,E.S., 

 discovered marine shells in Middle Drift, at an elevation of between 

 1,100 and 1,200 feet above the level of the sea,^ which nearly cor- 

 responds in elevation with the bed with marine shells on Moel 

 Tryfaen, described by the late Mr. Trimmer. As these are the 

 highest elevations in which marine shells have been fouad, and as 

 Mr. Hull, in his paper on the Manchester Drift, states, as Sir H, De la 

 Beche had done long before, that no erratic ascend the hills of that 

 district above an elevation of 1,800 feet, and that " not a trace of a 

 foreign rock occurs on the table-land of the Peak, which is about 

 2,000 feet high," it would appear that the fact of the absence of all 

 traces of marine action, during the Glacial and Post-glacial periods, 

 above an elevation of 1,700 feet in the Lake-district, is in accord- 

 ance with what has already been observed in East Lancashire, in 

 Derbyshire, Cheshire, and North Wales, and that there is little or 

 no proof that the north-west of England was ever submerged to a 

 greater depth during those periods,^ 



I cannot, therefore, agree with my friend Mr. Mackintosh, further 

 than admitting that the sea, in Pre-glacial times, acting along lines 

 of weakness, caused by faults and anticlinal axes, produced hol- 

 lows of undulation, which determined the way water should flow, 

 and in which rivers and brooks should cut down the step-like gorges 

 of our existing Lake- district. 



To those who state, with Prof. Sedgwick, that the proof of the 

 limited excavating power of rivers in the lake district is being 

 furnished by the small quantity of detritus they have yet been able 

 to deposit in the lakes which receive their waters ; it may be 

 replied, first, that the lakes not only receive their waters, but also 

 deliver them ; that the lakes, almost without exception, are nothing 

 but expanded rivers carrying detritus, not into lakes, but into the 

 sea. To take an instance : Codale and Easedale Tarns flow into 

 Grasmere, the latter into Rydal Water, whose waters, flowing down 

 the Eothay, enter Windermere. Blea Tarn, Langdale Tarn, Stickle 

 Tarn, Elter Water, all flow into Brathay, which, after falling over 



1 Hull, Mem. Lit. Phil. Soc, vol. ii., etc., p. 455. 



2 Darbishire, Gkol. Mag., Vol. II., p. 303. 



^ These three Drifts do not occur ia the Lake-district, and true Moraine Drift 

 descends as low as 100 feet above sea level. 



