332 FRA NK B UBS LEY TA YL OR 



are so lacking in the usual characters of moraines as to be not 

 surely recognized when taken by themselves. The occurrence of 

 an old river bed at the upper limit of a hillside belt of bowldery 

 till which has no particular morainic expression makes a combi- 

 nation as surely indicative of the presence of the ice-border as if 

 it were a well-developed moraine. One of the most remarkable 

 river beds of this kind runs along the flank of Dry hill between 

 Hartsville and New Marlboro. 



Outwash gravel fans also occur occasionally in such a way as 

 to mark the place of the ice-front where no certain morainic 

 deposits are discoverable. A small deposit of this kind in front 

 of a faint moraine occurs near the base of Mount Washington 

 west of Sheffield. 



There are several moraine-headed gravel trains in the Housa- 

 tonic and other freely drained valleys. These show the halting 

 places of the ice-front quite clearly and may be safely relied 

 upon. The gravel trains which head at Housatonic and at State 

 Line and at Pittsfield are good examples. 



Deltas occurring in association with moraines, and sometimes 

 also with kames, are also valuable adjuncts to interpretation. 

 The magnificent terrace at Lenoxdale combines moraine and 

 kame with delta. 



SOME DESCRIPTIVE DETAILS OF MORAINES AND BORDER DRAINAGE. 



A brief description of a few of the better examples of 

 moraines and border drainage will now be given. The morainic 

 deposits associated with the ice-front may be divided into three 

 or possibly into four classes : 



I . Frontal or marginal moraines, resembling those of the Great- 

 Lake lobes in the West. — These are ridges of bowldery till in 

 which clay is a relatively large constituent. They have usually 

 a swell-and-sag topography, but also more or less knob-and- 

 babin development. In the West this type of moraine is most 

 characteristically developed on a plain country along the straight 

 or gently curving margin of a great lobe. There is but one typi- 

 cal and strongly developed example of this class in Berkshire 

 county. This fragment runs three miles southeast from Pittsfield. 



