TRIASIC GROUP. 427 



are succeeded by beds of limestone. The marl and sand- 

 stone beds are of varied tints, though a dull red derived from 

 peroxyde of iron chiefly predominates. The name of new 

 red is given to this group to distinguish it from the old red 

 sandstone, which is often identical with it in mineral charac- 

 ters, but usually lies beneath the coal, though in some local 

 instances, in particular the great coal field of Dudley, the 

 old red sandstone, which is sometimes ten thousand feet 

 thick, is wanting, and the beds of coal repose on the under- 

 lying Silurian system. 



The following table exhibits the distribution of these strata 

 in the British localities in which they occur : 



I. Upper new red sandstone, or saliferous system. 

 Saliferous marls and sandstones. 

 Sandstone and quartzose conglomerate. 



II. Lower new red sandstone. 

 Magnesian limestone. 

 Lower new red sandstone. 



GEOGRAPHICAL DISTRIBUTION. This system, like the 

 last two groups, traverses our island from south-west to 

 north-east, and accompanies the lias from Devonshire and 

 Somersetshire, through the midland districts of Gloucester- 

 shire, Warwickshire, Lancashire, and Yorkshire, to Cum- 

 berland. It forms a region highly favoured by Nature, 

 though poor in fossil remains, containing rich stores of 

 gypsum, soda, and salt, and, from immediately overlying 

 the coal, presents at once such a stimulus and supply to 

 industry, that nineteen of our principal cities and chief seats 

 of commerce, from Exeter to Carlisle, are located on strata 

 appertaining to this group. Deposits of this character are 

 largely developed in France, in Germany, Italy, and European 

 Russia, as well as North America. 



ROCK-SALT AND BRINE SPRINGS. We have mentioned, 

 among the characteristics of this formation, its brine-springs 

 and stores of rock salt, which entitle this group to the name 

 of saliferous. The beds of new red sandstone which prevail 

 in Cheshire, where the chief salt-works are established at 

 Northwieh, and in Worcestershire, where the most important 

 springs exist at Droitwich, yield an inexhaustible supply. 



