Plate Tectonics Review

Continental drift is the idea that

• continents move over time

• some continents subduct under others

• Earth's magnetic pole has reversed

• earthquakes occur at plate boundaries

Evidence to support seafloor spreading includes

• similar rocks on different continents

• evidence of magnetic pole reversal on ocean floor

• fossils of animals and plants have been found on different continents

• rocks are younger at mid-ocean ridges, and older at the continents

Continental drift occurs because of

• Pangaea

• earthquakes

• seafloor spreading

• the Earth's magnetic poles have reversed

Where plates converge, _____________ can occur.

• mountains

• rift valleys

• volcanic arcs

• ocean trenches

The Himalayas form at a _________ boundary

• oceanic-oceanic convergent

• transform

• oceanic-continental convergent

• divergent

• continental-continental convergent

The Marianas Trench forms at a _________ boundary

• oceanic-oceanic convergent

• transform

• oceanic-continental convergent

• divergent

• continental-continental convergent

The San Andreas fault forms at a _________ boundary

• oceanic-oceanic convergent

• transform

• oceanic-continental convergent

• divergent

• continental-continental convergent

The East African Rift Valley forms at a _________ boundary

• oceanic-oceanic convergent

• transform

• oceanic-continental convergent

• divergent

• continental-continental convergent

The Mid-Atlantic Ridge forms at a _________ boundary

• oceanic-oceanic convergent

• transform

• oceanic-continental convergent

• divergent

• continental-continental convergent

Seafloor spreading occurs because

• earthquakes break apart the ocean floor

• new material is added to the asthenosphere

• hot, less dense material is forced upward

• sediments accumulate on the ocean floor