JOWETT AND MUFF : GLACIATION OF BRADFORD. ETC. 245 
head waters of the Calder. and east of this portion of the main 
watershed occurs an undoubted unghiciated area. Xo glacial 
deposits whatever have been observed, nor do the rocks exhibit 
glaciated or moutonnfe outlines, whilst masses of grit are seen 
weathered into the most fantastic shapes. Passing rooind the 
northern flanks of C'ombe Hill the ice edge may be traced almost 
due south and then E.S.E. across Hawoith Moor, and along 
the moor edge south of Oxenhope. its altitude gradually diminisli- 
ing. Then, turned north-eastwards by the moors east of Oxen- 
hope, the ice again pushed up the Harden Valley beyond Den- 
holme, and passing round Harrop Edge crossed into the Bradford 
basin. The lower parts of this basin u]3 to Leventliorpe and 
Clayton were completely tilled with ice. which also over-rode 
the eastern lip of the basin between Dudley Hill and Idle Hill. 
The drift-filled valley seen in section, near Low Moor Station, 
points to the conclusion that at the maximum extension a lobe 
of ice stood over the bioad depression in the watershed between 
the Aire and Calder at U'ibsey Bank Foot. From iiere the 
edge of the ice continued in an east-south-easteily direction, 
probably passing to the north of Drighlington. 
On the northern side of Airedale, after passing Rumbles 
Moor, the Airedale and Wharfedale ice again coalesced. Tlie 
Airedale glacier passed considerably beyond Leeds as the sporadic 
patches of boulder-clay and gravel containing erratics from the 
west on Whin Moor, at Scholes. and at Rothwell Haigh indicate. 
The distribution of the moraine mounds and tlie arrangement 
of the till in the transverse valley- east of Rumbles Moor seem 
to indicate that the Airedale ice began to retreat before the 
Wharfedale ice in that district. 
The position and direction of the striated rock-surfaces on 
Harden Moor, the packing of the till on the soutli-eastern slopes 
of the hills, and the distribution of Carboniferous Limestone 
and Silurian boulders, prove a general ice-movement from the 
north-west not only down the main valley of the Aire, but also 
transversely across tlie ridges separating the tributary valleys. 
There is no evidence that the tributary valleys, such as the 
Worth and Bradford basins, ever held local glaciers whicli 
originated on the hills at their heads and flowed down towards 
