134 
exposes sections at least sixty feet in depth, consisting chiefly 
of clay, with boulders of limestone, indurated shale, and grit. 
Above the blue clay, and resting on a very uneven and 
eroded surface, there is a thin covering of yellow clay, with 
grit and other boulders. About three miles north of Skipton, 
one side of a ridge consists of rock, the other side of drift. 
The blue clay, in many places near Skipton, contains shale in 
various stages of decomposition ; and east of the Grammar 
School, in a brick-pit, the highly-inclined limestone shale 
may be seen, exhibiting various gradations in the process of 
being worked up into blue clay. The stones and boulders, 
chiefly from the alternating limestone bands, may likewise 
be seen quite angular, subangular, rounded, polished, and 
scratched. In the cutting south of Skipton railway station, 
the blue clay comes nearly to the surface. In a quarry 
near to this cutting, one of the finest sections I have seen 
in Yorkshire has been exposed. The blue clay may be seen 
resting on the contorted beds of limestone — in one place 
on their edges, in another filling up a synclinal hollow. 
The limestone nowhere in this quarry shows any signs of 
glaciation. Between the blue clay and the yellowish or 
reddish-brown clay above there is a very distinct line of 
demarcation. 
[Mr. Mackintosh then described about forty sections of 
drift he had examined near Keighley, Hain worth- Shaw, 
Marley, Hombald's Moor, Bingley, Baildon, Guiseley, 
Holbeck, Headingley, Arthington, Follifoot, Eipley, Ripon, 
Littlethorp, south and west of Bramham, Marston Moor, 
York, Eoyston, &c., &c. On the various phenomena pre- 
sented by these sections he founded his explanations of 
the derivation and mode of accumulation of the drift- 
deposits. — For a number of the sections, see Plate, with 
accompanying explanations.] 
