USGS/CVO Logo, click to link to National USGS Website
USGS/Cascades Volcano Observatory, Vancouver, Washington

America's Volcanic Past
Volcanic Highlights and Features

Though few people in the United States may actually experience an erupting volcano, the evidence for earlier volcanism is preserved in many rocks of North America. Features seen in volcanic rocks only hours old are also present in ancient volcanic rocks, both at the surface and buried beneath younger deposits. A thick ash deposit sandwiched between layers of sandstone in Nebraska, the massive granite peaks of the Sierra Nevada mountain range, and a variety of volcanic layers found in eastern Maine are but a few of the striking clues of past volcanism. With this perspective, an erupting volcano is not only an exciting and awesome spectacle in its own right but a window into a natural process that has happened over and over again throughout Earth's history. -- Excerpt from: Brantley, 1994

Other Menus of Interest


URL for CVO HomePage is: <>
URL for this page is: <>
If you have questions or comments please contact: <>
12/03/07, Lyn Topinka