266 
DAVIS : ERRATIC BOULDERS. 
ON A GROUP OF ERRATIC BOULDERS AT NORBER, NEAR CLAP- 
HAM, IN YORKSHIRE. BY JAMES W. DAVIS. 
At Norber, about a couple of miles E.N.E. from Clapham, there 
is an immense assemblage of Erratic Boulders, some of immense^ 
size, weighing many tons ; their peculiar position on the slopes of 
a high hill, their dark masses, sometimes raised as much as two 
feet on a pedestal of white limestone, has rendered them striking 
objects of interest not only to the Geologist, but to all who may 
have ventured into the wild recesses of the mountains where they 
are situated. Especial reference was made to these rocks by 
Prof. Sedgwick in the year 1836, in the Transactions of the 
Geological Society, and Prof. Phillips has also more than once men- 
tioned them. Hitherto, however, no detailed description has been 
given of the erratics and the phenomena attending their displace- 
ment from their original bed and subsequent carriage and re- 
deposition in their present situations. I purpose in this paper to 
give as full an explanation of these subjects as I may be, first 
considering the general characters and the Geological constitution 
of the surrounding district ; and secondly, the nature of the 
erratics, the source from whence they were derived, and the 
agency by which they were carried and placed where they now 
occur. 
Norber is surrounded on the north and westwards by some 
of the highest mountains in England. Immediately behind it rises 
the mighty mass of Inglebrough, with Whernside beyond. To 
the westwards are Monghton Fells, separated only by Ribblesdale 
from the giant forms of Penyghent and Fountains Fell. South- 
wards is the broad valley of the Wenning, beyond which rises the 
hills of Brown Moor and Bowland Knotts. The character of the 
scenery on either side of a line drawn from N.W. to S.E. and 
running from Ingieton a little south of Norber and along Giggles- 
wick Scar to Settle is very different. This is the line of the great 
Craven Fault, on the southern side the strata are composed of 
Millstone Grits, and at Ingieton the Coal Measures are present ; 
the scenery is comparatively flat and tame, covered up to a great 
