Shorelines and Shoreline Processes - The Changing Earth: Exploring Geology and Evolution - page 424

6,

Upper limit
of wave
action

Image not available due to copyright restrictions

Breaker
zone

Direction of
long shore
current

Path
followed
by sand
grains

Direction of
wave approach

8. Although most beaches are made up
predominantly of quartz sand, there are
exceptions. This black sand beach on Maui in
Hawaii is made up of small basalt rock
fragments and particles of obsidian that formed
when lava flowed into the sea.

9. The beach
shown on Oahu
in Hawaii is
composed mostly
of fragmented
shells of marine
organisms,
although some
minerals from
basalt are also
included.

10. This California beach is made
up of quartz and sand- and
gravel-sized rock fragments.

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