Three Types of Plate Boundaries

DivergentConvergentTransform or strike/slip

Plates interact where they meet.

Divergent boundaries—Plates move apart

Example a spreading center--Mid-Atlantic RidgeThe Mid-Atlantic Ridge goes through Iceland.

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Or the Great Rift Valley in Africa

Convergent boundaries--plates move together

Three types of Convergent Plate Boundariesoceanic –oceanic

oceanic-continentalcontinental-continental

Oceanic-oceanic

results in subduction of one plate results in island arc volcanoes

Ocean-continental results in subduction of the oceanic plate

Ocean-continentalVolcanoes form when the oceanic plate reaches the lithosphere and begins to melt The less dense molten material rises and forms a volcanoBecause it is a mixture of basaltic oceanic crust and granitic continental crust, the lava is Andesitic

Like the Andes Mountains

continental-continental

Continental-continental

results in enormous mountains like the Himalayas.

Transform-fault boundaries--plates slide horizontallyExample--

Pacific plate and the North American plate slide past each other at the San Andreas fault.