NOTCHES THROUGH THE HOLYOKE KAXGE. 587 



THE GRANBY ROAD LAKE. 



At the second pass west of" the Belchertown ponds, ocon])ied by the 

 little-used road from Andierst to Granby, there expands in the center of the 

 pass a broad, flat plain of stratified sands (m t) at a level of 410 feet above 

 sea. The western half is well preserved. The eastern half has been deeply 

 notched by the waters of a spring-fed brook which escape toward the 

 north. North and south the road goes down over till to the lower and 

 later sands, but toward the south the watercourse by which the ovei-flow 

 passed into the basin to the south is well marked by thin layers of sand and 

 gravel. 



THE NOTCH. 



In the middle of the east-west portion of the range a pass 463 feet 

 above sea level has traces of coarse-bedded sands in its bottom, and is con- 

 tinued south in a deep canyon cut in the sandstones and underlying diabase, 

 down the side of which the road goes. This canyon I imagine to have 

 been cut by a torrent coming off the ice to the north and through the 

 notch, or at least to have been occupied and enlarged by such a stream. 

 (See p. 510 and PI. XI, p. 510.) 



THE LOW PLACE AND MOODY CORNERS LAKE. 



Farther west and just east of the Holyoke House is another pass, which 

 is, however, turned east by the great mass of the Black Rocks diabase, 

 and the waters coming through this pass in the same way seem to have 

 supplied the sands which filled up a small lake (m t) that extended east and 

 west between the two diabase ridges north of Moody Corners. This lake 

 stood at the height of 314 feet and drained from its west end southwardly 

 across the eastern tongue of the Black Rock dike where it is narrowest, and 

 it was filled with sands to great depth; the earlier sandstone having been 

 very deeply scooped out here by the ice. 



THE HOLYOKE NOTCH. 



The same flood waters continued farther west, and passed at this high 

 level between the ice and Mount Holyoke into the Springfield Lake, form- 

 ing the gorge terrace of Dry Brook Hill described on page 661. 



