356 J. D. Dana—Glacial Phenomena 
New Haven, lie several large bowlders of trap, and one of red 
sandstone, along with others of gneiss. One of the trap 
powlders contains over 200 cubic feet. Farther east, trap and 
sandstone bowlders are in rapidly decreasing numbers; and 
he same is true of the region to the westward. 
- If then, as we have shown, the flow of bi mass of the great 
glacier ier right angles to the Sound valley, it would have 
tended to move the ice of the Sound against and over Long 
Island, said? ne at all in the direction of the Sound, N. 75° E. 
To have had an eastward movement in the direction of the 
Sound the surface of the Sound-ice should have had a rising 
slope westward, and this is opposed by the facts already stated. 
It is certain, therefore, that the view that the Sound valley 
was excavated by the glacier is not tenable. Further, the 
lower ice-stream, or that of the Connecticut valley, struck the 
ice of the Sound in the direction S. 13°-25° W., which would 
the towns next west of the New Haven region but at times also 
nearly across the Sound before losing wholly its own direction. 
5. rpg J ages consequent on the change of course in the lower, 
y, ice-current manifested in the drift depositions. 
The following are the principal facts as to the deposition of 
the till: : 
(1) The till of the New Haven region is most abundant 
along the eastern declivity of the western border, east of the 
bowlders occur sparingly on the m part of Long Island, and a few 
reached even Block Island. Sandstone fecents have the same range but are 
far fewer, because less “auoae. Block Island is nearly east of New Haven, but 
8. 20° E. from the Triassic of central Massachusetts. To the westward, ee 
n 
und was nearly uniform from west to east, although the ea&tern end is h 
degree farther north than the western. 
