372 NEW YORK STATE MUSEUM 



dam and Hoffman, as Prosser has shown, and is in part mas- 

 sive, in part thin bedded and lumpy. At Tribes Hill there is 

 a 3 foot lumpy layer between the Lowville and Trenton which 

 he refers doubtfully to the Black River. At Canajoharie and 

 Spraker the Black River is absent, as is the Lowville, flat 

 Trenton beds lying diireotly on slightly folded Beekmantown. 

 In the dist:rict about Little Falls it isi sometimes present, but more 

 frequently absent, varying rapidly wlithin short distances. Thus 

 at Ingham Mills Prosser gives two sections, which the writer 

 has also seen, in one of which there are 5 feet of black, lumpy 

 limestone, capped by an 18 inch stratum which is lithologically 

 like the Lowville beneath. Near at hand, in the second section, 

 the succession is the same, but the Black River is only 2 feet 

 thick, though it is followed by the same recurrent Lowville 

 layer, above which the Trenton appears. At the old kiln, ^ mile 

 to the north, is a still better section, showing 8 feet of fossili- 

 ferous Black River limestone, underlain by a thickness of 10 

 feet of Lowville beds, and capped by the Trenton [pl.l]. As in 

 all cases hereabout, the rock is quite thin bedded and lumpy 

 with shale partings. Northward from Little Falls the forma- 

 tion is seldom present and then is very thin; the same is true 

 in the many sections about Middleville. About Newport it has 

 reappeared, with a thickness of 5 feet to 6 feet, thin bedded 

 and lumpy as at Ingham Mills. Followed northwest from here it 

 thickens, and becomes persistent and masisive. T. G. White 

 reports a thickness of 20 feet at Boonville and Lyons Falls, 

 respectively 25 miles and 35 miles northwest of Newport, in 

 the Black river valley.^ It is here for the most part quite mas- 

 sive, though somewhat shaly in its upper portion. 



Farther to the northward, there is little or no accurate pub- 

 lished information concerning the formation. Emmons gives 

 the thickness at Watertown as from 7 feet to 8 feet, and the 

 rock somewhat lumpy, though without shaly partings.^ All 

 along this side at the region the glacial deposits are exceed- 

 ingly heavy, making rock outcrops very exceptional and meager. 

 There seems however, no reason to doubt that the Black River 



2N. Y. State Mus. 51st Rep't, 1 : r27-29. 

 'Geol. N. Y. 2d Dist. p.386. 



