questions on volcanoes : LUSENET : Introductory Geology, Oswego State : One Thread

I have two questions on the volcanoes chapter, I am currently reviewing for the quiz on friday. The first is; is tuff considered to be tephra? or is it something that is totally different seeing it is not formed in the air? The second question is; are shield volcanoes, composite volcanoes, and cinder cones made from basalt magma, andesitic rhyolite magma, and basalt magma respectively? or is this the magma that comes out of the volcano when it erupts?

-- Greg Koscielniak (, February 28, 2001


Tuff is a rock that forms from tephra and other pyroclastic material that blankets an area and hardens from residual heat in the material.

-- Sharon Gabel (, March 01, 2001.

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