62 THE DALES OF DERBYSHIRE. 
of the limestone in Derbyshire; how it comes into its 
present position, and how it has been shaped as it is. The 
latter portion I have clearly demonstrated, and so I will 
now more particularly confine myself to the former. If we 
look at a geological map of England, we will see the light 
portion in the centre represents the area of the Derbyshire 
Dales. What brought it here? I say simply the normal 
movements of the earth’s crust. It has been squeezed in 
at this point, and the ordinary denudation of the country 
has moved the superincumbent matter away, just as a 
protruding nail is met and exposed by the carpenter’s plane, 
when planing an old board. This piece of limestone is 
here therefore for the above reason, but it is only a com- 
paratively small piece, thrown in by accident. Let us 
consult the map and notice where limestone crops up in 
other localities. We see it in Cumberland and Westmore- 
land underlying newer rocks, and if were to continue our 
search to the West and South of Ireland, and then return 
to Somerset by Devon, and, crossing the sea, follow it to 
the coal fields of France and Belguim, and finish our tour 
in Cumberland, we should have a circuit round Snowdon 
no larger than some that are being formed round peaks 
in the Pacific and Indian Oceans to-day. It is possible 
that these limestone beds are not continuous at the present 
time, but there is no definite reason why they should not 
be. The Irish Sea may have cut the connection, but we 
have no evidence on this point. 
If the position of the Derbyshire Dales, indicated on a 
geological map in plan and section be noticed, the coal 
measures lie upon the limestone, the millstone grit, Yoredale 
rocks, and shales intervening. These beds, and probably 
others, were continuous over the limestone; submarine and 
subaerial influences however planed them off to a certain 
extent, and left the main features as seen now. Further 
towards the close of the period which preceded the present 
