648 GEOLOGY OF OLD HAMPSHIRE COUNTY, MA8S. 



Farther south, the terrace swinging round either side of ]\Iount Doma 

 is continued in an exceptionally long spit of gravel which bends round 

 southwest and continues to Fort River, and beyond the river a peculiar 

 ridge of sand, sloping down gi-adually to the depression west of South 

 Amherst and westerly to the main basin, is can-ied south to the high ter- 

 race skirting the north flank of jMoimt Holyoke. This seems to me a bar 

 thrown across the mouth of the deep bay which occupied the second depres- 

 sion, mentioned above (p. 643), by the current of the main stream coming 

 down through the channel between ]\Iount Warner and the Amherst ridge. 



THE BENCH AROUND JMOXTNT WARNER. 



As one looks at this isolated rocky hill from Amherst a northern por- 

 tion, horizontal aiid at the level of the high terrace, attracts attention, and 

 investigation sliows this to be a broad, rudely horizontal rocky bench Ijut 

 slightly covered with loose material. To assume that this perfectly terrace- 



E -.-,.. ■-/, . — ^ w 



Flo. ,'in. — Detail of clay layer crumpled by the current, from iig. 38, to show how the layer was carried along hy the 

 friction of a current from the west . 



like portion of the mountain was planed down to the level of the liigh ter- 

 race by the flood waters would be to assume that this flood period was 

 immensely longer than we have been accustomed to think it, and longer 

 than the other phenomena connected with it would seem to warrant. 



An inspection of the map will show that south of the mountain a great 

 tail of sand extends southeast to the Northampton road. Just under the 

 south end of the mountain a pond occupies the place where the waters meet- 

 ing from both sides around the mountain stagnated and thus prevented the 

 sands from building up quite to the highest level, but farther south a broad, 

 pei-fectl}' level sand plain projects at the level of the high terrace southeast- 

 ward, indicating the direction of the current. (See map, PI. XXXV, C.) I 

 imagine it to have been deflected somewhat by the prevailing west wind. 

 This tail sinks like a delta southward and runs out on the clay bottom of 

 the lake, reaching nearly the Northampton road. On the west side it flanks 

 the mountain for a long wa}- north, but is so blended with dunes carried 

 up from below that its original relations can not be clearly made out. 



