A Geoscience Digital Image Library

TitleJumble of obsidian and pumice, Obsidian Dome, just north of Mammoth Lakes, California, USA
DescriptionObsidian Dome is a 600 year old (very young!) rhyolite dome near Mammoth Lakes in eastern California. It formed by rapid cooling of a viscous lava having the composition of a granite. The inner parts are relatively solid rhyolite, but the outer parts are a jumbled mass of boulders and rocks of various sizes. Much of the material is pumice and/or volcanic glass. A plaque near the dome says, “This mile-wide, 300 foot high rhyolite dome is one of a chain of similar domes extending from Mono Lake to the Inyo Craters. The domes in the northern two-thirds of the chain are known as the Mono Craters.”
Geologic provinceInyo Volcanic Field
LocationUSA ▹ California ▹ Mono. Near Mammoth Lakes. Inyo National Forest.
PhotographerDexter Perkins. 2001-05-22.
Key wordsrhyolite, obsidian, pummice, granite, dome
Tech details553 KB. Outcrop. Canon Eos Rebel, 55 mm lens, Fuji Sensia 100.
GeoDIL number560