233 
[Uphara. 
In Fourth Cliff (fig. 3) a section similar with the preceding, but 
only about half so long, and having some ten feet less height, pre- 
sents the same relationship of till and an underlying anticlinal de- 
Fig. 3. Section of Fourth Cliff; length, about 2,000 feet; height, 60 feet above the sea. 
posit of sand and gravel, the laminated structure of the till and the 
stratification of the modified drift being conformable with their line 
of division, but without interbedding there. Under the sand and 
gravel in this section a thickness of 5 to 10 feet of till is seen, 
extending also below the shore of boulders, along a distance of 
forty rods or more, and in one place these deposits exhibit very in- 
structive interbedding (fig. 4). The extent of the modified drift 
is nearly sixty rods, 
and its thickness 
ranges from 10 to 20 
or 25 feet. It con- 
sists wholly of sand 
and gravel, with no 
clay or fine silt, and 
with only the usual 
slight tinting of li- 
monite. Its central part lies between 20 and 40 feet above the 
sea, and is overlain by about 20 feet of till. A little south of the 
middle of the cliff, the stratum of modified drift is divided by a 
tapering, wedge-like accumulation of till (A in fig. 4), which thick- 
ens from three to six feet or more in a distance of a hundred feet 
from north to south, sinking meanwhile about seven feet, so that 
the underlying sand layer, four to five feet thick, which branches 
from the main stratum of modified drift and is intercalated be- 
tween two accumulations of till, dips in that distance beneath the 
upper line of the boulder-strewn shore. 
The north extremity of the tapering mass of till changes to a bed 
of boulders, cobbles and coarse gravel, which is three or four feet 
thick and extends about seventy-five feet into the finer modified 
drift, to which it gradually changes northward. Lying on the top 
of this coarse bed, a boulder (a) three to four feet long, and nearly 
as wide, projects with its whole thickness of one and a half feet 
into the overlying sand deposit. A short distance farther north I 
Fig. 4. Part of the section of Fourth Cliff, on enlarged 
scale; length, about 400 feet; height, 55 to 60 feet 
above the sea. 
