JOWETT AND MUFF : GLACIATIOX OF BRADFORD, ETC. 219 
<;lay occurs on the summit of Stone Hall Hill, Eccleshill, at 700 
feet above O.D. The boulders in the clay consist chiefly of 
Coal Measure sandstone, but include Millstone Grit, Carboniferous 
Limestone, and Silurian grit, all of which were found striated. 
The clay contained contorted lenticles of sand, whilst the shaly 
sandstone beneath was disturbed as if by a thrust acting from 
W.N.W. to E.S.E. (see above, p. 208). The boulder-clay extends 
down towards Apperley Bridge. 
In the Goole Quarries, to the south of Xewlay Station, 
30 feet of gravel, resting on the Rough Rock and banked against 
the hill side, runs up to a height of 75 feet above the river. The 
gravel is distinctly stratified only in places near the top. The 
pebbles are chiefly of Coal Measure sandstone, gannister, and 
Millstone Grit, but small Umestone and chert pebbles are fairly 
abundant. One small pebble of cleaved Silurian slate was 
also found (p. 199). In a note presented to the British Association 
in 1900 the Newlay gravel was stated to mark the last definite 
trace of the Airedale glacier in the valley. Although patches 
of boulder-clay were known to occur north and north-east on 
the higher ground between Airedale and Wharfedale, it was 
uncertain whether these deposits might not be due entirely 
to the Wharfedale glacier. The exposure of boulder-clay \^-ith 
striated boulders of gannister and Millstone Grit in the railway 
cutting east of Armley Station (Midland Railway), and of yellow 
boulder-clay ten feet thick with boulders of gannister, encrinital 
chert, and striated Millstone Grit at Rothwell Haigh, show 
that the Airedale glacier extended at least four miles S.E. of 
Leeds. The occurrence of boulder-clay with chert on Whin 
Moor, and in a quarry at Scholes on the north side of Airedale, 
also supports this conclusion. We are, however, unable to 
say how much further the Airedale ice extended. 
The wide embayment in the hills in which Silsden lies, 
on the north side of the Aire, is covered with boulder-clay. It 
extends beyond the northern edge of the map, where it is over 
40 feet thick in Cowburn Beck. To the south-west it is seen 
near Brunthwaite and below White Crag Plantation. In Dirk 
Hill Sike and Gill Grange Clough the boulder-clay, sometimes 
very gravelly, is 40 feet thick. It is a stiff blue clay, weathering- 
