TIDDEMAN : CARBONIFEROUS ROCKS IX UPPER AIRE-DALE. 485 
get a juster notion of the rebitive rate, duration and extent in depth 
of the several successive movements which combined have brought 
about the final results. Relative only, for so hr we have no positive 
scale to give us either the rate of the earth movements or of the 
formation of the deposits whose character was dependent on them. 
There is in the first place much presumptive evidence to be 
gained by consulting tlie Table of Rocks by any one who has a little 
personal knowledge of them. For instance, let us take (on the 
shallow side) the Carboniferous Limestone, 400 ft. It is nearly all a 
whitish or light crystalline limestone. Shales are seldom seen in it 
or are very thin. On the deeper side this is represented by Pendleside 
Limestone 0 — 400 ft., Shales with Limestone 2,500 ft., Clitheroe 
Limestone 3,250 ft. Of these three the first is very variable in 
thickness and sometimes absent ; the second consists much more of 
shale than limestone, and its contained limestones are often, in fact 
usually, very impure, besides being untraceable for any distance ; and 
the third, the Clitheroe Limestone, includes great thicknesses of shale. 
Then to go higher. The Yoredale Series on the shallow side contains 
many beds of pure limestone, persistent for the most part throughout 
the area. The Bowland shales on the deeper side contain no lime- 
stones at all. 
What is the general result to be gleaned here ? This : that in 
the shallower waters the Hmestones predominate, in the deeper waters 
the shales and mud. 
But we must be cautious ; all limestones are not shallow-water 
deposits ; all muds are not deposited in deep waters. There are 
differences in limestones, and we are enabled to determine that some 
of them are of shallow water formation and others probably made at 
greater depth. 
There are two very distinct kinds of limestone in the country on 
the downthrow side of the faults, the black, or blue as it is often 
called, and the white or light coloured limestone. They are not only 
distinct in lithological character but in bedding and general arrange- 
ment, as well as in their form in the mass, and the character which 
they give to the landscape. The black limestone is always well, 
evenly, and usually thinly bedded, and contains shaley partings. 
