Yoredale Rocks, — and it is in the latter rocks that the 
greatest amount of disturbance has arisen from it, in conse- 
quence of the fact that they are constituted not of thick, 
compact masses of sandstone, but of comparatively thin 
beds alternating with bands of shale. In this locality, in 
and around Ratcliffe Wood, there is a large number of 
sections, both natural and artificial, extending for several 
hundred yards to the eastern side of the fault, and after 
examining them and taking note of the dip in each case, it 
is easily seen that the greatest confusion exists among the 
strata; small faults are very numerous, and often prove 
themselves to be great obstacles to the quarrying operations 
there carried on ; and contortions of the beds, varying from 
only two or three feet to several yards in extent, abound in 
all directions. It is in the fissures produced by the disturb- 
ance of the beds in this locality that the mineral which I 
intend to describe in this paper is found. 
II. — Description of Section. 
The quarrying at Ratcliffe Wood is carried on chiefly in 
tunnels, formed by the excavation of the beds of rock which 
are best adapted for the purposes to which the stone is 
applied, namely, repairing and making roads. Some months 
ago the quarrymen met with a fault, which cut off the bed of 
rock that they were following, and in attempting to find again 
this lost stratum on the other side of the hill they opened a 
section nearer to the Red Rock Fault; and it was here that I 
first noticed the oxide of manganese, early in December last. 
This is the nearest section to the fault now exposed in 
that locality — with the exception of comparatively unim- 
portant exposures in the brooks running through the wood — 
and is probably not more than 30 or 40 yards from it. As 
this is a very interesting section, apart from its mineral 
characteristics, since it shows the effect of the force exerted 
during the production of the great fault, a somewhat brief 
description of it may, perhaps, be not out of place at this point, 
