Geology Reference
In-Depth Information
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Figure 11.16
Earthfl ow
Scarp
Scarp
Earthfl ows form tongue-shaped masses of wet
regolith that move slowly downslope. They occur
most commonly in humid climates on grassy, soil-
covered slopes.
a
An earthfl ow near Baraga, Michigan.
b
the only course of action is to sim-
ply avoid the area if at all possible
or, if the zone of creep is relatively
thin, design structures that can be
anchored into the bedrock.
Recall that many mass move-
ments are combinations of diffe-
rent movement types. When one
type is dominant, the movement
can be classifi ed as one of those
described thus far. If several
types are more or less equally
involved, however, it is called a
complex movement.
The most common type of
complex movement is the slide-
flow, in which there is sliding at
the head and then some type of
flowage farther along its course.
Most slide-fl ow landslides involve
well-defined slumping at the
head, followed by a debris fl ow or
earthflow (
Figure 11.22). Any
combination of different mass
movement types is a complex
movement.
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Figure 11.17
Quick-Clay Slide, Nicolet, Quebec, Canada The house on the slide (to the right
of the bridge and circled in red) traveled several hundred meters with relatively little damage.
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