204 FREDERICK G. CLAPP 



esker, one-half mile south of the Boston &l Albany Railroad, across 

 Newton to the frontal lobes of the Dedham Island and West Rox- 

 bury sandplains — a total distance of about six miles. 



Newtonville esker and plain. — The classical delta known as the 

 Newtonville sand plain, which has been described by Davis and 

 Gulhver,' lies fully a mile south of the railroad, about half-way 

 between Newtonville and Newton Center. It has an elevation of 

 150 feet, and averages fully three-fourths of a mile long and half a 

 mile wide, occupying nearly the whole breadth of the valley of Laun- 

 dry Brook. Several preglacial knobs rise through the plain, and to 

 the east it rests against a low rock hill capped by a drumlin rising to 

 an elevation of over 300 feet ; on the north and west sides are charac- 

 teristic ice-contact slopes; while a short stretch on the south forms 

 good frontal lobes. Viewed from any standpoint, the deposit is a 

 typical sand-delta, and well merits even more careful study than it 

 has received. A large excavation on Commonwealth Avenue gives 

 an unexcelled opportunity for viewing its internal structure. 



The feeding stream of the delta is represented by the Newtonville 

 esker, which first appears as it rises from beneath the lower and more 

 recent plain at Newtonville, about three-fourths of a mile north of its 

 junction with the sand plain. On both sides are large areas of 

 densely crowded kames and kettles, with which the esker in places 

 becomes somewhat confused. 



Southwest of the plain there is also a small kame area. Unlike 

 the southeast side, which has good frontal slopes, the southwest 

 corner immediately south of Commonwealth Avenue breaks up into 

 kames and kettles, which are composed of very coarse gravel, abound- 

 ing in bowlders up to several feet in diameter. Within four hundred 

 feet a further change takes place, by which the irregular hills become 

 shaped into a typical esker, bounded on both sides by kames, and 

 running in the direction of the Newton Highlands plain. Before 

 reaching this there is a short break, due to a swamp, but the parallel- 

 ism of the esker to the rock hill on the east, the close similarity 

 between the levels of the two plains, and the apparently perfect 



' W. M. Davis, "The Subglacial Origin of Certain Eskers," Proc. B. S. N. H. 

 Vol. XXV (1892), pp. 477-99; F. P. Gulliver, "The Newtonville Sand Plain," 

 Journal of Geology, Vol. I (1893), pp. 803-12. 



