BLACK RIVER LIMESTONE. 43 



water level. Not much, however, of its mass can be seen below the upper part, from the 

 rubbish, soil, etc. which skirt its base. It is very likely that more of it will be discovered 

 than was seen by us, but we can only give an account of that which was noted as having been 

 examined. 



The Black-river limestone has at its base or foot the primary rocks, the junction seen in 

 no part. From its surface the well-characterized Trenton limestone rises, showing its usual 

 mineral character, and its usual abundance of fossils. The two rocks, on the west side of the 

 river, are coextensive with each other ; but are seen together in one place only on the east 

 side, namely, just above Wheeler's mill in Oneida county, nearly opposite to Boonville, and 

 about four hundred yards from the dam. The Black-river limestone forms the bed of the 

 river for a short distance above that point, and continues down for about a mile. In the bed 

 of the river, some of the thin layers below the upper thick ones have been removed, causing 

 these latter to fall, and give a curvature to the surface. The action of water on the east bank 

 above and below the bridge, upon the same mass, has been great, deranging the surface, 

 removing some of the lower layers, and forming subterranean passages. This, no doubt, has 

 been caused by a portion of the water of the river, when very high, having found a passage 

 between the layers, gradually removing them by wear and by solution, just as may now be 

 seen near the mouth of Sugar river. At this latter place, the whole of the water, unless 

 when in freshet, disappears by the vertical joints of the thick surface layer, and finds its way 

 to Black river along the thin ones, portions of which are entirely removed. This is one of 

 those instructive localities, where a ready solution is found as to the cause and manner in 

 which caverns in calcareous rocks have been formed. These passages, some of which are 

 like ordinary caves, may be seen just below the surface rock, back of the quarry before men- 

 tioned, and along the course of Sugar river, from where it disappears, to its mouth. 

 * The vertical joints in the birdseye are more continuous in one direction than in the other ; 

 and tl4s was the only one noticed by the compass, of which a record was found, being nearly 

 east and west, and the other nearly at a right angle to it. At Parmlee's quarry, to the west 

 of Little-Falls, the most continuous joints were S. 86° E. ; and at Fort-Plain, the same sett 

 were S. 82° E. ; the others at nearly right angles as on Black river, making the common 

 general direction N. & S. and E. & W. for the vertical joints of this limestone. 



Base of the Trenton Limestone. On the Mohawk there are several quarries opened in a 

 mass of limestone, which rests upon the birdseye, as may be seen in three of them, and in 

 two of which it is followed by the well-characterized Trenton limestone. This mass, there- 

 fore, holds the same position as the upper division of the Black-river limestone, and contains 

 some of the same fossils ; but the mineral character is different, resembling more the grey 

 limestone of the upper mass of the Trenton limestone. 



These quarries are, Stanton's, on the south side of the Mohawk, about half a mile below 

 Amsterdam ; Pumam's quarry, on the hill to the east of the village of Tripes hill, and the 

 quarry by the side of the railroad at the depot ; Sage & Reed's quarry, opposite Tripes hill, 

 on the south side of the river ; Humphry's quarry, on the same side, between Fultonville and 



