Source: University of Wisconsin-Madison
Illustration by: Dan Brennan.
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For further assistance regarding the content of this illustration, contact Terry Devitt, 608-262-8282, For further assistance regarding the use of this illustration, contact Nick Weaver, 608-263-9141,

Caption: A cross section of a quartz crystal obtained from rocks near Yellowstone. Crystals of quartz and zircon harbor geochemical clues to past -- and future -- volcanic eruptions in the Yellowstone caldera. In the past, eruptions over this "hot spot" in the Earth have been of a magnitude that would have severely altered Earth's climate.
Image credit: Ilya Bindeman and John Fournelle, remastered in Adobe Illustrator by Mary Diman
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