Igneous rocks begin as magma. Intrusive igneous rocks, like granite, form when magma cools inside the Earth. Extrusive igneous rocks, like the basalt lava flow in this photo, form at the Earth's surface. Volcanic rocks are extrusive igneous rocks. Photograph by Steve Mattox, July 1990.

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Hello Volcano Fans!


As you might have noticed we are in the process of changing to a new style of website.   This is a significant upgrade over all previous versions of VW and will allow this website to carry on for some time into the future without any further changes.   We understand and apologize that things have been changing so often here, but each step has been required for us to keep the website going.   This change will guarantee that VW is always up to date!


Most of the older content is still here!! 


I suggest using the search box on the homepage first.  

You can also try our sitemap @ http://volcano.oregonstate.edu/view/sitemap


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Click here for a list of activities and teaching suggestions about Minerals, Magma, and Volcanic Rocks.

Click here for a list of references about Minerals, Magma, and Volcanic Rocks.

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