CARBONIFEROUS. 



149 



The Lake District and parts of North Wales suffered much 

 disturbance and denudation after the Silurian period, for the 

 Upper Old Red conglomerates, or Basement beds of the 

 Carboniferous series, rest with marked unconformity on the 

 older rocks. 



After the deposition of the Coal-measures great disturb- 

 ances took place before any newer strata were laid down in 

 the English area. The upheavals were attended by many 

 undulations of the strata, and accompanied or followed by 

 great denudation ; and the Coal-measures are preserved for 

 the most part in the synclinal folds, which form the Coal- 

 basins.^ While as De la Beche remarked in 1846, "From the 

 movement of the older rocks many a mass of Coal-measures 

 may be buried beneath the Oolites and Cretaceous rocks on 

 the east, the remains of a great sheet of these accumulations, 

 connecting the districts we have noticed, with those of 

 Central England and of Belgium, rolled about and partially 

 denuded prior to the deposit of the New Red Sandstone." - 



Fig. 20. — Diagrammatic Section across the Pennine Anticlinal.^ 

 {]. W. Davis.) 



Lancashire. 



Yorkshire. 



d. Coal-measures. 

 c. Millstone Grit. 



6. Yoredale Rocks. 



a. Carboniferous Limestone. 



The Pennine Chain was upheaved, perhaps mainly after 

 the Permian period, although its elevation must have been 

 commenced soon after the close of Carboniferous times.'* 

 Broadly speaking, it constitutes a faulted anticlinal of Lower 

 Carboniferous rocks, supporting on the east the Coal-fields of 

 Northumberland, Yorkshire and Derbyshire, and on the west 

 the Lancashire and Cheshire Coal-fields. (See Fig. 20 and 

 Fig. 3, p. 25.) 



The Carboniferous rocks were mapped for the Geological Survey in South 

 Wales mostly by Sir William E. Logan ; in Gloucestershire and Somersetshire by 

 William Sanders and D. H. Williams, with revisions in the Mendip Hills by H. 

 W. Bristow, W. A, E. Ussher, J. H. Blake, and the writer. In the Midland 



^ See Sedgwick, T. G. S. (2), iv. 57. 



^ Mem. Geol. Survey, vol. i. p. 214 ; Godwin-Austen, 0- T- xii. ■xS. 

 3 G. Mag. 1878, p. 504. 



* E. Wilson, Geol. Mag. 1879, p. 500; Midland Naturalist, iii. I, iv. 97, etc. 

 see also E. Hull, G. Mag. 1879, p. 573, and Q. J. xxiv. 323. 



