HERKIMER COONTT. 257 



mouth of the creek, under the Trenton limestone. On Stony creek below Middleville, and in 

 other points of that section, the limestone also appears. 



Where a black marble is wanted, the Trenton limestone can readily furnish all that may be 

 needed : It takes a good polish ; some of it is very fine grained, of colors varying from grey 

 to black, the latter often relieved by the white or light-colored fossils which are so profusely 

 buried in this rock. Trials of this limestone from Rathbone's, opposite to Newport, have been 

 made, which showed a fine pohsh, ar.d handsome surface. 



The limestone also appears on Easi-Canada creek, at the uplift below Brocket's bridge, and 

 at the uphft of Little-Falls on both sides of the river ; the south end showing the limestone 

 upon the top of the uplift, from whence it may be traced continuously to the west of Parmlee's 

 quarry near the canal, where it disappears under the Utica slate. 



The Utica slate forms in general the higher elevations of the county south of the Trenton 

 limestone, and those north of the river ; the exceptions being caused by upUfts, and the appear- 

 ance of the Frankfort slate which covers Hasenclever hill : the lower part of the mass contains, 

 in this county, the thin flag-like layers. The slate lines the south border of the river at the east 

 end, extending about two to three miles from the river, and diminishing in width at the west 

 end. Along the north side of the river it is concealed by alluvion, which extends along the 

 river from Little-Falls to Oneida county. On the south it is not so much covered, being visible 

 in many of the small streams which empty int« the river. 



The Frankfort slate, with its thin layers of sandstone or rubblestone, rises upon the Utica 

 slate, and shows a much greater breadth of surface, and is considerably exposed along the 

 side-hill, also through Fulmer valley ; in parts of Steele's creek ; at Dygerts ; and in Myers' 

 creek, back of Frankfort village especially. No fossils were seen in the rock, except some 

 fucoids, probably attached to the sandstone, and a graptoUte : these were from Myers' creek. 

 It there shows high cUfis, with a sUght dip south, the mass finally disappearing under the 

 conglomerate below the furnace. 



Throughout the county, the Oneida conglomerate appears resting immediately upon the 

 Frankfort mass. It shows generally about an equal proportion of pebbles and sand. The 

 lower part, towards the middle and west, exhibits about ten inches of pyrites, apparently 

 cementing the pebbles. The mass is thicker at the west, than at the east end. It shows itself 

 in a small terrace to the south of Mohawk village, from which the grey sandstone of the Clinton 

 group is seen as a cliff above, forming a greater length of terrace than the conglomerate rock. 



The Clinton group, Uke all the preceding masses, is well exposed in the many water courses 

 which flow north to the river, the succession being well observed in many, and the parts also 

 of which it is composed. This group, so important for its red fossiliferous ore beds, extends 

 east and west through the county ; its surface in some parts more exposed than in others. It 

 is a useful group in this county, containing an immense deposit of light grey sandstone, which 

 shows itself at the east end of the county. It first appears at Grill's, extending thence with 

 a constantly increasing thickness towards Myers' creek. Where thickest, it is about eighty 

 feet. It is now used for hning the enlarged canal, being well fitted for walling, having nume- 

 rous divisions which give the required size for ordinary building. No use is yet made of its 



Geol. 3d Dist. 33 



