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TYPES OF CONTINENTAL MARGINS
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Continental margins are not all alike, but they are not all different either. There are two basic types. Each one has different characteristics, which are a function of the processes involved in the formation of the two types of margins
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The “classic” margin is based on the U.S. East Coast example. This margin is an example of what is called a “passive” margin because earthquakes and volcanoes are essentially absent here; as the plate on which this continent rides moves away from the Mid-Atlantic Ridge.
The other type of margin is modeled after the U.S. West Coast. This margin is sometimes characterized as an “active” margin because it is on the leading edge of the North American plate. Margins along plate boundaries are mountainous with narrow shelves, steep slopes and rugged topography. Passive margins have wide shelves and gentle slopes. There are no trenches along passive margins, but active margins may be associated with trenches, Can you identify which margins are passive types and which are active types on other continents?
Continental margins have the same characteristics as the adjacent portion of the continents. Thus, the margin off California is rugged and steep, as is California. The margin off of Texas and the states along the East Coast is wide and flat. The Texas coast and the East Coast have flat coastal plains bordering the ocean. You can easily predict the type of continental margin if you know the topography (land shape) of the adjacent land mass.
