BIGSBY PALAEOZOIC ROCKS OF NEW YORK. 349 



everywhere ; often like millstone-grit. It also has beds of breccia, 

 and ends upwards in grey or white unfossiliferous limestone. 



The masses belonging to it in Oneida County are thus described 

 by Emmons, p. 124 : — 



1 . [From below] A greenish, fine-grained, even-bedded sandstone, 

 with thin green slaty layers interposed, and sometimes enclosed also 

 in the rock. 



2. A reddish-brown sandstone, the layers 4 to 24 inches thick, 

 alternating with layers of the same colour. 



3. White, grey, and reddish limestone, terminating downwards 

 in the preceding rock. Its beds are always thick ; and the whole rock 

 is massive and chequered with seams of spar and quartz. 



4. A greenish breccia ; its fragments not coarse, but very strongly 

 cemented together. Its colouring matter often appears to be chloritic ; 

 and, when the mass is fine, it has a trappean appearance. 



5. A conglomerate of rounded pebbles of quartz, united appa- 

 rently without cement. It is confined to Oneida County, and has 

 no fossils. 



Now comes the unfossiliferous limestone. It is rarely a homo- 

 geneous rock, and is seamed and veined with quartz and spar. 



Transition. — We are told by Emmons (p. 406) that the Hudson- 

 River-group is succeeded by this sandstone in Jefferson County; 

 and Hall says " that in Oswego and the adjacent counties the Pu- 

 laski shales of the Hudson-River-group slowly change into grey 

 sandstone, — the fossils ceasing, the green matter disappearing, till at 

 length the new stratum is completed. Passing upwards here, the 

 grey sandstone mingles with Medina sandstone,— the latter differing 

 chiefly by its colour, and the grey limestone being often spotted with 

 the colouring matter of Medina sandstone ; so that there is here a 

 gradual passage from Hudson-River-group to Medina Sandstone." 



The grey sandstone was a sandy beach washed by advancing and re- 

 tiring waves; for Lingulce are found on it, fixed on little ridges of stony 

 matter. It has also wave-lines like those of our present beaches. 



Place. — The Grey sandstone, according to Vanuxem, is found in 

 Oneida, Lewis, and Oswego Counties. It begins a little south of 

 Rome, and covers a large area in the two latter counties. Hall finds 

 it in the west and south, in the townships of Camden, Florence, 

 Mexico, Newhaven, Scriba, Oswego, and Lewis. 



Position. — This is an undisturbed rock ; but it has a perceptible 

 inclination to the south-west. 



Thickness. — In Jefferson County the thickness is about 100 feet, 

 taking in the grey limestone. In other places Emmons makes it 

 1500 feet, including all the individual masses (Rep. p. 127). I 

 think Prof. Emmons does not here distinguish this rock clearly from 

 the Oneida Conglomerate. 



Fossils. — There are very few fossils in the Grey sandstone. They 

 are Lingula cuneata, Avicula demissa, and Strophomena nasuta, the 

 last found by Emmons, near Rome. They are confined to the lower 

 part of the rock. Some fine species of Fucoids have been found 

 (Mather, p. 369) at New Hartford Centre and Hampton Village. 



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