New Red Sandstone. 209 



beautiful examples of this structure in hand specimens ; and it is par- 

 ticularly interesting that these cannot be distinguished by the eye from 

 specimens from Nova Scotia, associated with gypsum ; and therefore 

 unquestionably belonging to the new red sandstone group. Similar 

 specimens may be obtained at South Hadley Canal on the West Spring- 

 field shore. 



Mineralogical Characters of the New Red Sandstone. 



" Taken as a mass" says De la Beche* the group (of new red 

 sandstone) may be considered as a deposit of conglomerate, sandstone, 

 and marl, in which limestones occasionally appear in certain terms of 

 the series ; sometimes one calcareous deposit being absent, as the 

 muschelkalk is in England ; sometimes the zechstein, as in the east 

 and south of France ; and sometimes both being wanting as in Dev- 

 onshire." "The beds" says Dr. Macculloch,f are sometimes of a 

 conglomerate structure, at others a fine sandstone and occasionally 

 schistose ; and in composition, the rock is calcareous, argillaceous, or 

 ferruginous, or all together presenting endless variations of aspect 

 and color." 



These descriptions correspond in general to the group which I de- 

 nominate new red sandstone in the Connecticut valley. Our rock, 

 however, is more deficient in calcareous matter than is usual in Eu- 

 rope : though more or less of lime is scattered through all the mem- 

 bers of the group ; so that in some cases even the reddish shales 

 slightly efferverse with acids : and might, therefore, be properly cal- 

 led red marl. Nearly all the limestone in the group is highly fetid ; 

 though in some instances this passes into that which is bituminous ; 

 and even into bituminous marlite. 



It should be recollected, also, that this formation is wanting in gyp- 

 sum and rock salt ; two minerals found in it almost universally : 

 though as mentioned in the first part of my report, a minute quantity 

 of the former has been found at West Springfield, and South Hadley. 

 I have however, compared a suite of specimens from the new red 

 sandstone containing gypsum in Nova Scotia, with a suite from the 

 Connecticut valley, and with the exception of the limestones, they can 

 hardly be distinguished from one another. Indeed, why may we not 

 suppose gypsum and rock salt to be occasionally wanting in this for- 

 mation, as well as limestone ? 



* Geological Manual p. 386. 



t System of Geology, vol. 2. p. 227. 



27 



