Environmental Engineering Reference
In-Depth Information
Glacial till over shallow rock
Kame terrace
S
tra
tif
ied
drift
CONT
OUR INTERVAL 10
FEET
DATUM IS MEAN SEA LEVEL
FIGURE 7.91
Portion of USGS quad sheet (Mt. Toby, Massachusetts) giving approximate topographic expression for
Figure
7.90e.
(Courtesy of USGS.)
Clay
Silt
2.0
Sand
Clay
1.5
Silt
2.5
Sand
Clay
1.5
FIGURE 7.92
Failed triaxial test specimen of varved clay
(Hartford, Connecticut). Three-inch
undistributed tube specimen from a depth of
30 ft.
Silt
Sand
and occasional periods of high stream flow resulted in the deposition of sand partings and
lenses. When winter arrived, the lake froze over, meltwaters ceased to flow, and the clay
particles settled out of the quiet waters. When summer returned each year, a new layer of
silt was deposited, and the sequence continued year after year.
