210 J. D. Dana on the Glacial and Champlain eras. 
for some cause—probably, ) the melting taking place over the 
surface at large, instead of along the southern edge chiefly, and 
(2) the diminished slope of the surface (due to the fact that the 
subsidence of the crust which introduced the Champlain era 
increased in amount to the northward), the two causes dimin- 
ishing, if not stopping, over large regions, the movement of the 
ice—none were left over the general surface, or even along the 
larger valleys. 
XVL No distinct terminal moraines of the Glacial era have 
been observed in New England. The great glacier terminated 
in the ocean on the east, southeast and south : ; and it may be 
— = oe its decline, in the Champlain era, the melt- 
appears to have gone forward over too vast an extent of 
aiince ie the. formation of proper terminal moraines. Having 
a thickness on the border of 2,600 feet, it must have filled 
Tone Island Sound as a consequence of its weight, even if the 
Sound—but 150 to 250 feet deep and 15 to 20 miles wide,— 
had not been partly obliterated by a change in the water-level ; 
and thence it stretched on over the island (which is about 15 
miles wide) to the ocean. If the land of Long Island were but 
120 feet higher above the water-level than now, the southern 
coast would have been 20 miles outside of the present line; 
and, whether so or not, the — if 2,100 feet thick over the 
early Champlain era or that ‘of the melti ting genes * so, if 
the glacier over the island in the Glacial era had the thickness 
above supposed. 
s already stated, whatever there may be of local morain ines 
in the White Mountains belo ongs to the pend. of melting, and 
therefore to the opening part of the Champlain era. 
XVIL. ne Champlain+ era, as the enithes been ised by me. 
fy oe investigations mn land. Mather in his 
Geol. ees (4to, 1843) goers set eek vee ein the drift of Long 
eek and the mans weg se its boulders. 
+ The term Champlain was first applied to deposits of this era 
on Lake Cham- 
plain side Hitchcock in the e Vermont Pt ons roche _ Champlin ee 
‘oe 
- 
