Topography of the New Red Sandstoue. 



217 



eration. In New York, also, according to Prof. Eaton,* this forma- 

 tion commences near Utica, and extends 250 miles in length. East 

 of New England, no new red sandstone has been found nearer than 

 Nova Scotia, where it abounds in gypsum. From the able descrip- 

 tion of this rock by Messrs. Jackson and Alger, and from specimens 

 furnished me by this latter gentleman, I infer a greater resemblance 

 between the Nova Scotia and New England group, than between the 

 latter and that in New York, and those farther west : although of the 

 last named I have as yet seen only few specimens. 



As the general direction of the strata of the new red sandstone in 

 the valley of the Connecticut is north and south, and the dip easterly, 

 it will follow that the lower beds of the group must occupy the wes- 

 tern part of that valley. And I have already remarked that the 

 greenstone ridges generally separate the upper from the lower beds. 

 In Gill, Greenfield, and on Mount Holyoke, however, the observer 

 will see schistose sandstones cropping out beneath the greenstone ; 

 though in receding westerly from the greenstone, he will find the 

 slaty character of the rock soon to disappear. 



In the central parts of the Connecticut valley, from South Hadley 

 nearly to Middletown, the shales and finer sandstones prevail almost 

 exclusively; so that in excavating 15,000 cubic yards of stone at En- 

 field Falls, not a pebble as large as an acorn was observed.! The 

 prevailing colour of the slate in that region is dull red or chocolate ; 

 and being easily decomposed, it imparts a like hue to the soiL If we 

 suppose, what I have always observed to be true, that the prevailing 

 dip of the strata through the whole valley is easterly, we cannot ad- 

 mit, as some have maintained, that these finer strata were originally 

 deposited in its central parts, and the coarser materials on its borders, 

 for then the finer strata must dip on both sides of the valley towards 

 its center, or remain horizontal ; and they could not dip under the 

 coarser layers on the east side, as they now do. We ought probably 

 rather to infer, that the higher and coarser strata have been worn 

 away from the central portion of the valley, because they would there 

 be more exposed to abrading agents. 



The coarser and the finer beds do not, however, in all cases occupy 

 separate portions of the valley exclusively : but in many places they 

 are interstratified in almost endless variety. The section laid bare 



* Survey of the Erie Canal, p. 102. 



tMr. A. Smith on the Connecticut valley. Am. Journal Science. Vol. 22. p. 220. 



28 



