RELATIONS OF GRAVEL DEPOSITS 211 



side shows a beautiful lobate front, which, together with the absence 

 of kettles and the scarcity of modified drift immediately to the south, 

 indicates that in that direction was an open lakelet three to four miles 

 in extent. The overflowing water, reinforced by the drainp,ge from 

 an extensive area to the west, found its outlet eastward through a 

 large superglacial or marginal stream. 



Lower Falls, Wellesley Hills, and Waban plains. — These are all 

 about 150 feet in elevation, and the first two originally formed a single 

 plain. Extending in an irregular line from near Rice Crossing north 

 of Wellesley Hills to Newton Lower Falls, and thence to the high 

 morainic hills east of Riverside, is a kettled and kamey ice-contact 

 nearly three miles in length. Large kettles south and east of the 

 Lower Falls indicate that the glacier to the north was almost con- 

 nected with the decaying ice-blocks on the southeast side of the plain; 

 but that it was not quite continuous is indicated by consideration of 

 the fact that the slopes on both sides of the river are erosion slopes, in 

 which artificial excavations show nearly horizontal stratification, 

 probably once continuous across the valley. The Waban plain, lying 

 closely adjacent to the Lower Falls plain on the east, was formed by 

 the Auburndale esker stream.' It is bounded on the north and south 

 by ice-contacts, is much broken up by kettle-holes, and might properly 

 have been classified with the Newtonville-West Roxbury group, with 

 which it is closely connected. 



Other plains of the series. — In the valleys east and west of Dover 

 are two or more small plains at approximately the same elevation, 

 which are shown by ice-contacts on their valley sides to be deposits 

 of small marginal embayments. Plains of the Newtonville-West 

 Roxbury type occur in the Medfield-Medway basin of the Charles 

 River, and also in the Neponset valley. The uniformity of elevation 

 over such a wide area strongly suggests dependence upon some lake- 

 outlet east of the Neponset valley. No systematic search for such an 

 eastern outlet has been made in the field, but it is known that in the 

 southern watersheds of the Charles and Neponset Rivers there is 

 no pass lower than 200 feet above tide. 



' J. B. WooDWORTH, " Some Typical Eskers of Southern New England," Proceed- 

 ings oj the Boston Society oj Natural History, Vol. XXVI, pp. 197-220; W. M. 

 Davis, " The Subglacial Origin of Certain Eskers," ibid.. Vol. XXV, pp. 477-99. 



