Upham.] 
232 
[April 17, 
every storm, show very distinctly a complex structure of associated 
deposits of till and modified drift. 
Both the north and south ends of Third Cliff (fig. 2) for a dis- 
Fig. 2. Section of Third Cliff; length, about 3,000 feet; height, 70 feet above the sea. 
(The base of the section is at the top of the shore of boulders, 10 feet above the sea.) 
tance of about fifty rods at each end, where the hill-slope rises from 
near the sea level to the height of 50 or 60 feet or more, that 
is, nearly to the full height of this drumlin, are composed wholly 
of till, the usual very compact and hard gravelly and stony clay, 
with frequent large boulders ; but in the central portion of the sec- 
tion only its upper half or third is till, and this lies upon beds of 
gravel, sand, and clay, which in the middle and greater part of 
their extent are very nearly horizontal in stratification, but dip down 
in slopes of 3° to 6° toward each end, the slopes terminating the 
nucleal mass of modified drift being somewhat steeper than those 
of the surface of the drumlin. A feature especially noteworthy is 
the conformability of the stratification of the modified drift with 
the line of junction which separates it from the overlying till ; but 
no seams of gravel, sand or clay were observed within the till 
above, nor were any layers or masses of till, nor any boulders, 
seen enclosed in the modified drift. The section shows the two 
deposits divided by a definite and regular line, which curves down 
at each end. Throughout its whole extent, the bedding of the mod- 
ified drift and the obscure lamination, which is commonly a char- 
acteristic of the till and is distinctly seen here, are parallel with 
each other and conformable with the line of division. The upper 
part of the modified drift is mainly sand and gravel to the thick- 
ness of 10 or 15 feet, enclosing fragments of stone up to six or 
eight inches in diameter, but no boulders. Beneath are beds of 
laminated dark gray clay or very fine sandy silt, which form the 
greater part of the deposit of modified drift toward the north, while 
its corresponding lower portion at the south consists mainly of 
coarse sand, much of it stained yellow or brown with limonite. The 
modified drift of Third Cliff extends below the slope of boulders 
that forms the shore, and its base is not exposed to view. 
