ii 
THE GREEN STREET DIKES. 
The prominence which has ever been attached to the Syra- 
cuse Serpentines proper, since their discovery by Vanuxem in 
1839, together with the fact that the original locality has long 
been lost but is now known, will warrant a brief description of 
the dikes. 
For several years past the dikes which must have been the 
source of the intruded sheet in James street, (the original Foot 
street of Vanuxem) has been locally known as the Green street 
dike. ‘This was because the grading of Green street, which par- 
allels James street 600 feet to the southward, cut into the dike and 
left a permanent exposure, sometimes referred to in the local dail- 
ies as the Green street volcano. When this entire section was 
piped for city water in 1894, three additional and nearly parallel 
dikes, not previously known to exist, were temporarily exposed. 
As the excavations to a depth of eight feet were in progress 
through this entire section at the same time, and as they remained 
open for over a week it gave an excellent opportunity of locating 
the dikes and of tracing them to other localities as well. The fol- 
lowing facts were obtained at that time. 
Dike I. The water trench is situated on the north side of 
Green street, and extends in a northeasterly direction, cutting 
through all of the dikes at nearly right angles. Dike No. 1 begins 
at 283 feet east of the east crosswalk on Lodi street. It is nine 
paces in breadth and even in the trench had been entirely altered 
to greenish-yellow earth. This was the decomposition product of 
the peridotite. I have traced this dike but forty feet south and 
five feet north of the trench. 
Dike II. At the top of the trench this dike and the preced- 
ing would appear to be one, but there is a little doubt that a wid- 
ening of the fissure in its upper part causes a contact here of two 
distinct dikes. In the very bottom of the trench a mass of hard 
limestone, two feet across, separates them. This dike is 14 paces 
in width and contains practically nothing but the greenish-yellow 
serpentinous earth. Southward I have traced it to excavations 
in the rear of Clinton school, northward to a point twenty-five 
feet beyond James street, a total distance of 1050 feet. 
