196 



GEOLOGY OF THE THIRD DISTRICT. 



Between the different parts of the Ontario division, no striking point of superposition was 

 noticed in that section of the district ; the one of most interest, was the connection between 

 the Grey and Medina sandstone on the west side of the river at the village of Oswego, where 

 the two rocks show an interchange of each other's color. The Grey sandstone extends from 

 the lake toward the dam, near which, at a higher level, the Medina sandstone is seen, the two 

 rocks having a slight dip south. 



No. 1. Grey sandstone. 



Seetum near the movtk of Oswego river. 

 No. 2. Medina sandstone. No. 3. Allurial. No. 4. Lake Ontario. 



The only parts of the district where the Medina sandstone, the Oneida conglomerate, or the 

 sandstone which represents this mass, and the Clinton group, are nearly in juxtaposition, is 

 in Cayuga county. The best point for observation is at Bentley's quarry on the road from 

 Martville to Hannibalville. There the Red sandstone and the Clinton group are within a few 

 feet of each other, having a grey sandstone intervening, which is intermixed with the green 

 shale of the Clinton group, presenting the same characters and the same position as the grey 

 band of Rochester. The Medina sandstone forms the lower part of the quarry, and the two 

 other masses the higher ; the junction between the red and grey sandstone is concealed by 

 drift, etc. No section was prepared of this quarry, by mere omission. 



South of the Mohawk, through Herkimer county, etc., the hills and ravines afford fine 

 sections of the connection between the masses from the conglomerate upwards, this rock 

 through all that part resting upon the Frankfort slate. 



Seetum north and smdkfrom Pidmer valley, by Fox hoUmo and Crugar's mill, etc., south in the loans of German-flatts 



and Warren. 



No. \. ExliibiUi the Frankfort slate, etc., which forms the bottom of the ralley 



2. Oneida conglomerate. 



3. Clinton group, with the giey sandstone mass at the top under the milL 



4. Red shale, and other masses which belong to the Onondaga salt group. 



5. Water-lime group, quarried to the south of Mr. Crugar's. 



6. Pentameros limestone, forming the top of the two hills south of the quamy on the road to Richford's springs. 



