650 Gi:OLOGY OF OLD HAMPSHIRE COUNTY, MASS. 



across the Hampton plain. Along this portion of its course, between Nona- 

 tuck and 3Iount Tom, tine bowlder beaches mark the outer boundary of the 

 high terrace. 



THE ^XTISTFIELD PLAIN. 



I have followed the high terraces on either side of the broad Hadley 

 Lake and found them much more intimately connected with the Southamp- 

 ton Valley than through the gorge of Mount Holyoke with the Springfield 

 basin. They are confluent with the broad Westfield })lain, one of the most 

 interesting deposits of the river. 



The broad, unfilled lake, 15 miles wide opposite Northampton, nar- 

 rowed across Southampton to a width of 3 miles, and on the .south line of this 

 town two long ridges. White Loaf and the high hill to the west of it. East 

 Farms Hill, rose as islands in its course, and the waters passed on south by 

 three narrow channels — respectively 180 rods, 1'20 rods, and 360 rods wide, 

 counting from west to east — into the Westfield plain, the filled-up portion 

 of its ancient bed. These passes formed a waste gate through which the 

 overflow of the river went with velocity accelerated by the narrowing of 

 its passageway. It swept the abundant kame sands (m t) which had been 

 spread at the western foot of the Mount Tom range and over White Loaf 

 through the eastern and middle channels, and this is the proximate source 

 of the trap pebbles traced far south across the plain by Mr. Diller.^ The 

 sands of the Manhan were spread by it over the western portion of the plain- 

 As a result, we have coarse gravels concentrated from the kame gravels in 

 the eastern gorge, stretching far south across Hampden plain and growing 

 gradually finer, and in the same latitudes on the western side of the plain 

 the sands are much finer, being derived from the sands of the Manhan. 



That the sand here had this origin in local kame deposits is manifest 

 from the fact that along the whole course of the Holyoke-Tom divide there 

 are no streams flowing into the river to bring sediment, and through all this 

 length the high terrace is for long distances wanting or marked only by a 

 narrow shelf cut into older deposits, and certainly nothing was brought 

 from the upper waters of the river across the broad, low clay bottom of 

 the lake in Easthampton. 



The delta deposits of the Loudville branch, swept along the west side 

 of the basin, had, south of Southampton village, shrunk to a naiTOw shelf, 



'J. S. Diller, Geol. of Westfield: Westfield Times and News Letter, Sept. 19, 1877. 



