On Saturday we stopped to take a photo of Black Butte, an extinct volcano near Mt. Shasta. It looms over I-5 as you pass Weed, CA. Northern California is home to many volcano's in the Cascade Mountain Range, most are extinct. The Cascades start in Canada and wind their way through Washington, Oregon, and into California.
-- Geographic Setting, Geologic and Eruptive History - Two of the main eruptive centers at Mount Shasta, the Shastina and Hotlum cones were constructed during Holocene time, which includes about the last 10,000 years. Holocene eruptions also occurred at Black Butte, a group of overlapping dacite domes about 13 kilometers west of Mount Shasta. ... The extrusion of the domes about 9,500 years ago was accompanied by the formation of pyroclastic flows which extended more than 10 kilometers south and 5 kilometers north of the domes. -- Excerpt from: Miller, 1980, USGS Bulletin 1503
I found that excerpt at:
http://vulcan.wr.usgs.gov/Volcanoes/BlackButte/Locale/framework.html
http://en.wikipedia.org/wiki/Black_Butte_(California)
For information on scenic volcano drives in California, check here:
http://www.summitpost.org/area/range/334003/california-cascades.html
