3o8 The American Geologist. November, 1903 
and experts have examined the upper Salt with that end in 
view. The scheme is to tunnnel through Horse-Shoe bend 
and by thus shortening the river increase its fall. Moreover, 
in thus tunnelling through the Archaean mountain that causes 
the bend in the river, the plan is to narrow-in the tunnel 
towards its western (lower) terminus and thus concentrate 
the whole volume of the river at one point to run a powerful 
electric plant. This plant, it is expected, judging from the 
volume of water now in the river, will not only have power 
enough to light the town of Globe, move the tram-cars at 
the mines and separate many of the ores by the electro-process ; 
but in addition will furnish light and motor power for the 
cities of Tucson, Prescott and Phoenix. 
References. 
i. G. K. Gilbert, U. S. Geogr. Sur. west of the 100th Meridian, Vol. 
III, pp. 163-4. 
2. G. K. Gilbert— Ibid, p. 164. 
3. G. K. Gilbert — Ibid, p. 165. 
4. A. R. Marvine — Ibid, p. 223. 
5. Oscar Loew — Ibid, p. 587. 
6. G. K. Gilbert — Ibid, pp. 526-7. 
7 G. K. Gilbert — Ibid, P527. 
8. A. R. Marvine — Ibid. p. 221. 
9. A. R. Marvine — Ibid, pp. 221-3. 
10. G. K. Gilbert — ibid, p. 528. 
11. Oscar Loew — Ibid, p. 642. 
Uniz'ersity of Indiana, June 2$th, 1903. 
PROBABLE PRE-KANSAN AND IOWAN DEPOSITS 
OF LONG ISLAND, N. Y.* 
By M. L. Fuller, United States Geological Survey. 
There are on Lonk Island two great gravel formations oldc r 
than the Wisconsin: (1) the Pensauken, and (2) the Man- 
hasset. The Pensauken consists largely of quartz pebbles, but 
carries occasional granitic fragments, which, in rare cases, may 
comprise a third of the pebbles. These pebbles, whether basic 
or acid, small or large, are alike rotted throughout, and can be 
readily crushed in the hand. The gravels rest on an eroded 
* Published by permission of tbe Director of the United States Geological 
Survey. 
