Geology Reference
In-Depth Information
Other depositional features of shoreline processes are illustrated in Figure 15-8 and in-
clude:
Spits:
Spits
are long ridges of sand that project out into the water, often in a hook-
like shape. Spits usually form parallel to the shoreline.
Baymouth bar:
A spit that continues to grow until it closes a bay off from the
ocean is called a
baymouth bar.
Tombolo:
A
tombolo
is a shallow ridge of sand that connects a small island or sea
stack to the mainland along the coast.
Figure 15-8:
Features of coastal
deposition.
Categorizing Coastlines
Coastlines shaped by the processes of wave erosion and transport are called
secondary
coastlines.
For example, much of the east coast of the United States is secondary coast-
line, shaped by marine processes.
Other coastlines, called
primary coastlines,
have features dominantly shaped by different
surface processes (such as those discussed in Chapters 12 and 13). An example of a
primary coast is a region where glaciers meet the ocean, such as the west coast of
Canada and southeast Alaska. The carving of the landscape by the glacial ice (I describe
glacial erosion in Chapter 13) is what creates the features of these coastlines.
