504 



J. W. Davis — The Valley of the Calder. 



substance -witli which we are all so familiar. Besides these rich 

 deposits of vegetable origin, with their beautifully preserved speci- 

 mens of ferns and other land-plants, there occurs a great number of the 

 fossil remains of shells and fishes which lived in the water, and also 

 of a few insects and labyrinthodonts which existed mainly on the 

 land. SjDecimens of these fossils may be found on almost ssiy pit heap, 

 and are especially abundant in the Halifax Coal-strata and above 

 the Better Bed Coal of the Lowmoor district. 



After this digression, we must hasten to consider some of the 

 physical forces which are, or ought to be, the subject of this paper. 

 Perhaps the most important is the great internal force which caused 

 the elevation of the chain of hills dividing this county from Lan- 

 cashire, called the Pennine Chain of Hills or the Backbone of Eng- 

 land. This upheaval is part of an extensive system of faults which 

 extended primarily in two directions, viz. one running north and 

 south — the Pennine system of faults — extends from the eastern 

 side of the Lake-district southwards to Staffordshire, passing, on its 

 way, along the western boundary of Yorkshire. The second great 

 line of faults is in an easterly and westerly direction. They are 

 called the Craven Faults. They branch from the Pennine Faults 

 near Ingleton, and, proceeding eastwards along the foot of Ingleboro', 

 pass behind Settle to Malham, and thence still further into Wharfe- 

 dale. The displacement of the rocks by these faults is very great. 

 In Lunedale the New Eed Sandstone abuts against Silurian rooks, 

 and the beds must be displaced to the extent of nearly 3000 feet. 

 At Ingleton, the Coal-measures are placed by the Craven Fault on 

 a level with Silurian rocks ; further east, at Malham, the Mountain 

 Limestone on the north is in a line with the Millstone-grits on the 

 south side of the fault. 



In the district we are considering the break seen in the rocks is 

 not so distinct, but they are forced up into an anticlinal as repre- 

 sented in the subjoined diagram. 



Diagrammatic Section across the Pennine Anticlinal. 

 Lancashire. TorksMre. 



4 3 2 1 2 3 



1. Mountain Limestone. 3. Millstone Grit. 



2. Yoredale Rocks. 4. Coal Measure. 



To understand this action it will be necessary to premise that 

 the earth's crust is constantly changing its form, even at the 

 present time, and that, formerly, the changes appear to have taken 

 place much more rapidly. The strata or rocks of which the outer 

 surface of the earth is composed are not everywhere of the same 

 thickness and strength, and, consequently, are not able to bear 

 uniformly a lateral pressure, such as would be produced by the 



