Mountains, Plains, and Escarpments. 331 



Millstone Grit and Carboniferous Limestone forming 

 the Derbyshire hills, 4'. These strata dip first to the 

 west, underneath the New Red Sandstone, and then 

 roll over to the east, forming an anticlinal curve, the 

 Limestone being in the centre, and the Millstone Grit 

 on both sides dipping west and east; and above the 

 Millstone Grit come the Coal-measures, also dipping 

 west and east. Together they form the southern part 

 of the Pennine chain. Upon the Coal-measures in 

 Nottinghamshire, Derbyshire, and Yorkshire, dipping 

 easterly at low angles, we have, first, a low escarpment 

 of Magnesian Limestone 5, then the New Red Sand- 

 stone and Lias plains 6 and 7, which are covered to 

 the east by the Oolite 9, forming a low escarpment, the 

 latter being overlaid by that of the Chalk 11. In this 

 district, except in North Yorkshire, the Oolitic strata, 

 being thinner, do not form the same bold scarped table- 

 land that they do in Gloucestershire and the more 

 southern parts of England. As shown in the diagram 

 the Cretaceous rocks also rise in a tolerably marked 

 escarpment. 



Further north the grand general features are as 

 follows : If a section were drawn across England from 

 the Cumberland mountains south-easterly to Bridling- 

 ton Bay, the following diagram, fig. 68, will explain 

 the general arrangement of the strata, and the effect of 

 this on the physical geography of the district. 



On the west there are the Green Slates and por- 

 phyries, No. 1, consisting of lavas and volcanic ashes, 

 hard but of unequal hardness, and some of them, there- 

 fore, by help of denudation giving specialities of form 

 to some of the loftiest mountains of Cumberland. Then 

 comes 2, the Coniston Limestone, overlaid by Upper 

 Silurian rocks, 3, forming a hilly country, between which 



