6 



ing much less argillaceous matter than the Helclerberg lime rocks as 

 shown by their more complete solubility in acid. They are of a dark gray 

 color, and though not as light as the Onondaga limestones usually are, 

 they nevertheless show by their fossil remains and structure that they 

 belong to this group. The cut north of* Manlius is 100 feet long and 

 about 12 feet deep. Opposite St. John's School are two cuts each 270 feet 

 long aud from 6 to 8 feet deep, separated by an interruption of 400 feet 



2. Rocks of this formation are found abundantly at the Indian Res- 

 ervation quarries south of Syracuse, at Jamesville, (Green Pond and 

 elsewhere), at Chittenango Falls (upper strata), and near Munnsville (X. 

 Y. and O. M. It. R.) These localities are not far from an east and west 

 line crossing Onondaga and Madison counties hear their centre. 



3. The rocks are dark gray, semi-crystalline limestones almost en- 

 tirely soluble in hydrochloric acid. They are compact and free from 

 the shaly structure so frequent in the rocks of the preceeding group. 



4. Some fossil remains may be found in the rocks of this group; 

 large irregular Favosites (honey-comb coral), Cyathyphylloid coral, 

 fragments of the stems of Crinoids, and imperfect Brachiopods are the 

 principal forms in the cuts, yet fossils are neither as common nor as 

 perfect as at either Jamesville or Chittenango Falls. 



5. The beds on the immediate line of railroad are not utilized at 

 present, yet at various parts of Onondaga County they are quarried ex- 

 tensively for lime and for the valuable building stone they furnish. The 

 gray limestone is used quite extensively for entire buildings of which 

 the University, the Onondaga County Saving's Bank, and the new 

 Catholic Cathedral in Syracuse, are fine examples. It is also used quite 

 commonly with red brick for trimmings, and to some extent for monu- 

 mental work, of which tine specimens may be seen in Oakwood Ceme- 

 tery. This rock has the peculiarity of becoming black when polished, 

 even when the uncut stone is of a light gray color. It burns to a pure 

 white lime. 



d. HAMILTON GROUP. 



1. The rocks of the Hamilton period are separated into three well- 

 marked groups all of which are represented on the line of the road. 

 The groups receive distinctive names as follows : — (a) Marcellus shale, 

 so called from Marcellus, Onondaga County, X. Y., where it appears in 

 considerable quantities; (b) The Hamilton proper from the outcrops in 

 the hills near Hamilton, Madison County; and (c) The Genesee shale 

 named from the Genesee River, where it prominently appears. The 

 Tully limestone, intermediate between the last two, occurs in a small 

 part of the area occupied by the Hamilton formation, but is not gen- 

 erally distributed. 



2. a. M areellus Shale.— About two miles south of Oran is found a 

 cut in the Marcellus shale about 500 feet long and from 25 to 30 feet 

 deep. At the western entrance of the tunnel the Marcellus appears 

 to some extent though here it seems to blend and lose itself in 

 the rocks of the Hamilton proper. A little to the southwest of 

 the tunnel is a ravine, wholly below the level of the tunnel, cut in the 

 same shale as deep as 00 feet. The shale here is more bituminous 

 than tli at above or in the cut first mentioned. Septaria of large 

 size are found in the bed of the steam. 



b. Hamilton proper. — The rocks of the Hamilton formation proper 

 are found only at the tunnel west of Cazenovia Lake. This structure 

 is about 1G00 feet long with a rock cut at the western approach of 

 560 feet, and at the eastern of (530 feet, making a total length of nearly 

 2800 feet. The rock beds at the western entrance are cut through 2!) 

 feet in depth and at the eastern 35 feet, From the elevation of the 

 land forming the hill through which the tunnel extends, and from the 

 general thickness of the drift deposit in the immediate vicinity, it would 

 appear that the rock not far from the eastern entrance is 50 or 60 feet 

 in thickness above the track; 



