Luther — Economic Geology of Onondaga County. 



295 



Lodi street a few years ago, a cut was made exposing a section of the rocks, 

 200 feet long and 12 feet high at the highest point. 



In the fall of 1895, a ditch for water mains was dug seven feet below the 

 street grade, enlarging for a few days the exposed section to that extent. The 

 rocks uncovered are the thin bedded and shaly magnesian limestones that 

 occur immediately above the horizon <>f the rock salt beds, and lie <„, the 

 southwestern slope of an anticline, the outlines of which are obscured by the 

 drift. They are much flexed and broken by the emotion of the material com- 



Figure 12. The location of the peridotite dike in the city of Syracuse. 



posing the dikes. The principal dike is twelve feet, four inches wide at the 

 surface of the road bed, and approximately the same to the bottom of the 

 dike. Above the sidewalk the width increases to the Top of the bank, where 

 it is twenty-five feet, and a layer eight to ten inches thick is spread over the 

 surface of the rocks for several rods toward the east, thinly covered by the soil. 

 Another and much thinner dike occurs about one hundred feet west of the 

 main one, and there are evidences of two others, also small. The middle por- 

 tion of the main dike is composed of quite firm and hard, dark green peridotite, 



