66 



SUMMARY OF THE NEW RED SYSTEM. 



until they attain in these central tracts an importance as great, perhaps, as that 

 of the same deposits, in Yorkshire, Durham, and Cumberland 1 . 



Among the peculiarities of the Lower New Red Sandstone of this region, one of the 

 most remarkable is the prevalent diffusion of calcareous matter, and the existence of 

 bands of concretionary limestone, some of which pass down into the coal measures ; 

 in which respects the formation differs essentially both from its type in the North of 

 England, and from its foreign synonyms. 



A practical acquaintance with the lower member of this system, is, it must be 

 allowed, of vast national importance ; for, as these sandstones are now proved to 

 graduate into the coal measures, we need not despair of eventually finding some of 

 the most valuable coal seams of the central counties extending beneath them. Such 

 results would indeed be only a repetition of the successful enterprize by which, in 

 sinking through deposits of the same age, the south-eastern part of the county of Dur- 

 ham, in spite of the prejudices and predictions of the old school of miners, has now 

 been rendered a great productive coal tract. 



If such be their practical value, these inquiries may also lead geologists to modify 

 their previous theoretical views, respecting the relations of the coal measures to the 

 overlying rocks, founded on what must now be considered local phenomena, observed 

 chiefly in the Bristol district and south-western parts of England ; where because the 

 New Red Sandstone reposes ^conformably upon the carboniferous strata, the belief 

 became prevalent, that this arrangement was indicative of a general rupture, subsequent 

 to the accumulation of the coal measures, and anterior to the deposition of the mag- 

 nesian limestone and conglomerate. That such, however, has not been generally the 

 case, has been established with regard to the North of England, by the writings of 

 Professor Sedgwick ; and the preceding facts teach us the same lesson in respect to the 

 central counties : for it is clearly demonstrated, that beds of the age of the dolomitic 

 conglomerate are there separated from those of the carboniferous system, by an un- 

 broken succession of intermediate strata of vast thickness, of which there are few or 

 no traces in the south-western parts of the island. 



Notwithstanding, however, the distinctions which have been drawn between the dif- 

 ferent members of the New Red System in the central counties, a question it is feared 

 might still arise among foreign readers, concerning the true equivalent of the Rothe-todte- 

 liegende : for as most Continental geologists conceive that formation to be essentially 

 connected with porphyritic and other rocks of igneous origin, they can scarcely peruse 

 the description of the trappean conglomerates, p. 51 etseq., without supposing that those 



1 These subdivisions of the New Red System of this region are not always easily recognised, owing to the 

 prevalent obscuration and small elevation of the strata; and there is great difficulty in marking with precision 

 their separate courses with accuracy. Two subdivisions only are therefore attempted upon the annexed map, 

 viz. 1st, Marls, Sandstone, &c. ; 2nd, Lower Red Sandstone including the overlying calcareous conglomerate and 

 the inferior courses of concretionary limestone. 



