408 MR. BERXAKD S3HTH ON THE [Sept. 1912^ 



The top of Black Combe (1969 feet) was overridden by compara- 

 tively clean ice, which ascended the gentle northern slopes, signs 

 of its passage being furnished by a iew scattered bonlders near the 

 Cairn. There is plenty of evidence of the ice-movement over the- 

 lower shoulders of the mountain. 



y. (1) The Lake-Disteict Ice. 



The Lake-District ice moved from three main directions : (i) the 

 Broughton Valley ; (ii) the Duddon Yalley and the high ground on 

 the west ; and (iii) Eskdale. 



(i) The Broughton Yalley. — AV. T. Aveline ^ states that in 

 the first of these districts the Broughton drift chiefly consists of 

 scattered angular or partly waterworn stones, and large ' perched 

 blocks.' In places it has filled up some of the deep valleys, 

 which generally have been again excavated by the existing streams,, 

 showing a rocky bottom. Where the drift assumes any thickness, 

 as on the side of some of the valleys, it is found to consist of travelled 

 stones or boulders scattered in a finer matrix derived from the dis- 

 integration of the surrounding rocks. He records huge erratics of 

 volcanic breccia on Broughton Moor, and one (the 'Eed Gall Stone') 

 on Tower High Common, but none of them seem to have travelled 

 far. Some huge boulders of Coniston Limestone on Broughton Moor, 

 and the fragments of dark graptolitic mudstones in the drift near 

 the Coniston Copper Mines, have apparently come from the north- 

 east. 



(ii) The Duddon Yalley and the high ground on the 

 west. — The Duddon Yalley, cut entirely in volcanic rocks, is beauti- 

 fully glaciated. On looking up the valley we see the craggy faces of 

 the cliff's and rocky knobs ; but, on looking down, we notice that the 

 smoothed backs of the knobs, partly covered by grass and with their 

 bases often plastered about with boulder-clay, give to the scene a 

 remarkably smooth and tame appearance. 



In the lower part of the valley, between TJlpha and the Duddon 

 Bridge, are splendid examples ofroches moutonnees. The ice- 

 movement was here from north 30^ east. 



Of the upper part of the valley Mackintosh - writes : — 



'The eastern slope .... of the Duddon is covered with a succession of 

 gently-swelling knolls (with rocky nuclei) of pinel, and overlying loam, both 

 containing large boulders. In many places there are rocbes moutonnees, 

 with parallel undulations or wide ^^-shaped grooves (as well as minute striae) 

 pointing north-north-east, or nearly in the direction of the valley.' 



Thus the general direction of ice-movement between the 

 Broughton-Coniston and Duddon Yalleys was south-westward from 

 the direction of the Coniston Fells, crossing the Duddon Yalley 

 between Ulpha and Duddon Bridge obliquely. West of this part of 

 the valley ice-moulded surfaces, occasional stride, and rock-grooves, 



1 MS. report. - Geol. Mag. vol. viii (1871) p. 306. 



