352 FRA NK BURS LEY TA YL OR 



and between their ends, which lap past each other, there are 

 fragments of another moraine at East Lee and Washington. 

 Supposing the successive moraines to be distinct individuals, as 

 stated above, the correlation of fragments of other moraines 

 with either of these continuous sections has the same significance 

 as though they were correlated with the same point in a single 

 series. These relations furnish the basis for reconstructing the 

 several recessional ice-borders. 



BRANCHING AND INTERLACING SERIES OF TERMINAL MORAINES. 



With the aid of two or three ice-borders made out clearly as 

 continuous units for distances of twenty or twenty-five miles, 

 like those just mentioned above, it becomes possible to recon- 

 struct other near-by ice-borders whose continuity is not so clear 

 when taken by themselves. This can be accomplished by the 

 correlation of branching and interlacing series of terminal 

 moraines in their relation to the identified continuous lines. 



The most favorable condition for the formation of a complete 

 series of moraines that shall make a perfect record of the suc- 

 cessive recessional halts occurs where a deep, narrow valley 

 drains directly away from the receding ice-front and keeps this 

 relation during many successive halts. This is the relation of 

 the Farmington valley. From its head near East Lee it cuts 

 through the plateau a few miles to the east, then turns to the 

 south, and passes out of the county and out of the Housatonic 

 quadrangle near the southeast corner. The earliest ice-border 

 which rested within the area of the Housatonic quadrangle crossed 

 the extreme southeast corner a mile west of West Hartland. It 

 was a re-entrant angle of the ice-front and is a faintly developed 

 feature, but it is here designated as No. i of the series. Count- 

 ing up the moraines in the Farmington valley, beginning with 

 the one north of Riverton as No. 2, we find that the deposit at 

 West Becket on the line of the Becket moraine is the sixth, the 

 one east of East Lee the seventh, the one at Lenoxdale the 

 eighth, and the one at Pittsfield the ninth. The moraines of 

 this series are distinct, well-formed individuals, and would be 

 readily recognized by any experienced observer. A careful 



