1867.] 343 [Perry. 



It Avas for a lono; time asserted, and I suppose the afRriiiatlon is still 

 made, that this rock which lies along the western limits of the State 

 dipping- eastward, underlies more recent formations on the east, and 

 is immediately succeeded by them, as we pass in that direction; that 

 tliese are probably of Silurian * and Devonian age, and follow the 

 Sandstone in regu'ar gradation; that having been subjected to intense 

 heat, or having undergone changes through some other such agency, 

 they have been greatly transformed ; in short, that all the so-called 

 Taconic rocks as described by Dr. Emmons, and after him by Pro- 

 fessors Adams and Thompson, are later than the Red Sandstone, and 

 have been sq metamorphosed in structure, and obscured by the oblit- 

 eration of fossils, as to be in most cases recognized only with extreme 

 dithculty, if at .all, in their true character. 



In reference to these points it may be said generally, that the posi- 

 tions assumed tlo not seem to be sustained by facts. It is hardly neces- 

 sary to remark, that the rocks referred to as lying directly to the east, 

 do not ordinarily exhibit any such nyirks of metamorphism as the 

 theory implies. And I need not now linger to state in detail, that 

 more careful search has shown that some beds of the Taconic roqks 

 are not a little fossiliferous. The first prominent fact, then, to which 

 I would particularly refer is this: the Red Sandstone does not run 

 imder the formations which usually lie next to it on the east, as the 

 dip might at first suggest. It simjily rests on them in all the localities 

 at which I have been able to find the exposed junction of the two 

 rocks. Instead of passing under, the Sandstone often abuts against, 

 these so-called newer formations, and sometimes apparently as if it 

 had been shoved upon them, or they forced against it. That this is 

 so may be seen in Swanton — to mention no other places — where, at 

 several points, the Potsdam band has been entirely cut through, and 

 large jjortions of it have been removed.f Exposures are thus afforded 

 by the excavated gullies and valleys, which extend easterly and west- 

 erly, giving a view of the underlying rocks, as they occasionally crop 

 out, as well as of the overlying sandstone, which flanks these ravines 

 on the north and the south. In these cases, cliffs composed of the 

 Red Sandstone merely repose on, or occasionally lie as if they had 

 been thrust against, the formations which succeed on the east; while, 

 in no locality, have I been able to find them running, or any evidence 

 that they actually proceed, under the so-called more recent masses. 



*Thcywei-o considered Upper Silurian, etc., when tbe Eed Sandstone was re- 

 garded as Medina ; now, perhaps, they would be viewed by some as Lower Silurian, 

 and so on. 



+ There is needed, and it was my intention to give, at least one sectional diagram, 

 illustrative and confirmatory of each main stratigrapliic position advanced in this 

 paper. It is hoped, however, that the matter will be plain, beyond mistake, even 

 without a single diagram. 



