142 TJie American Geologist. March, 1900 
54 1632 Prof. Kemp reported on 
chips from this horizon 
as follows: "It is granit- 
ic gneiss, usual Archean 
type and contains quartz, 
biotite and probably or- 
thoclase. Sand from 
1632, drillings appar- 
ently from a rock like the 
chips contains quartz, 
orthoclase, little pla- 
gioclase, biotite and 
zircon." Bottom of well. Archean gneiss 
A piece of rock, said by the drillers to have been obtained 
from between 1,400 and 1,560 feet, contains, according to Prof. 
Kempt, "orthoclase, quartz and apparently decomposed biotite, 
now chlorite. It is a pegmatyte and looks to me like a piece of 
a pebble from a conglomerate." 
Samples of the drillings from this well from 1,560 feet 
down to the bottom were examined by Prof. J. F. Kemp, of 
Columbia University, and Dr. A. C. Gill, of Cornell University, 
and they agree in referring the lower part of the well section 
to the Archean. Prof. Kemp wrote that "all the samples ex- 
amined are rather characteristic of the quartzose or granitic 
gneisses, which are very widespread in the Adirondack 
Archean, for all the phases of composition cited above can be 
matched readily among them."* 
Dr. Gill reported that the samples "represent a series such 
as occur in surface exposures in the Adirondacks and are all 
crystalline. In the surface exposures studied there is an alter- 
nation of layers containing much hornblende with others in 
which it is not so conspicuous. The specimens are surely 
Archean gneiss." 
This well reveals a deep channel under the city, filled by 
drift, which has been mentioned by Prof. Brigham.f The 
line between the Hudson and Utica shale is not accurately 
known, since no samples were saved from the lower 144 feet 
of the Hudson River ; but if that shale continues to a depth of 
350 feet then there are only 300 feet of Utica shale in this well. 
*Letter of Nov. 30,1897. 
tBull. Geol. Soc. Amer., vol. q, p. 190, 
