No. 275.] 245 
band" of Rochester. The rocks succeeding to the grit, are the green shales, 
the iron ore beds, the calcareous " fire stones," &c. &c. of the protean 
o-roup; the whole terminated by its upper member, the concretionary 
rock of Oneida, which with its immediate associates appear in the low 
level near Oneida lake, passing thence through the towns of Cicero, 
Clay, Lysander, Ira, and Victory, in Onondaga and Cayuga, thence on- 
wardly, and finally forming the upper falls of Rochester, the rock of the 
e;reat excavation of Lockport and the falls of Niagara. 
From the information obtained from Mr. Hall, of the geology of the 
north side of Lake Ontario, we learn that the southern limit of the 
Birdseye and the Trenton limestone is near Newcastle, opposite to Ro- 
chester; and the southern limit of the shales of Salmon river is at Cre- 
dit river, about fifteen miles west of Toronto; both extending westward 
in the same direction as in this State. From these facts we are enabled 
to solve points of the highest importance, and as obscure as were the 
connection of the series of rocks which form the great south elevation 
of the Mohawk valley, with those of the middle region and those of the 
mountain ridge or terrace of Niagara. 
Red Sandstone of Oswego. 
The red sandstone of Oswego is the lowest rock of the three coun- 
ties whose examination forms the subject of this report. The counties 
are, Madison, Onondaga and Cayuga. The red sandstone is only found 
in Cayuga in the town of Stirling, underlying the north half of the 
town. It is not to be seen in many places, owing to its alluvial cover- 
ing. The locality where it is uncovered to the greatest extent, is on 
Little Sodus creek, at Stirling centre, where it is likewise quarried for 
building. From the centre it extends along the creek to McFarlane's 
mill, a mile south. At the centre, a brine spring rises by the side of the 
creek, through a fissure in the sandstone. There is another spring also 
near the mill. At both places, salt was made, and of similar quality; 
both had a sharp taste; that of Stirling centre was highly coloured with 
iron, which mineral the spring deposits. Care being taken to purify the 
salt at the mill as to colour, it was white. 
The red sandstone is the lowest rock, geologically, of New- York, 
which contain brine springs of sufficient purity to be manufactured into 
salt. From the eastern part of Oswego county, to the Niagara river, 
numerous brine springs are found in this red sandstone.* All the 
springs in the Third District, which are found in this rock, and there 
*See Report of Fourth District. 
