A Geoscience Digital Image Library

TitleObsidian at Obsidian Dome, Inyo Volcanic Field, 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. They cooled so quickly that most of the material is not crystalline. Here we see a large boulder that is mostly glass (obsidian). It also contains lesser amounts of gray pumice.
Geologic provinceInyo Volcanic Field
LocationUSA ▹ California ▹ Mono. Near Mammoth Lakes. Inyo National Forest.
PhotographerDexter Perkins. 2001-05-22.
Key wordsObsidian Dome, obsidian, pummice, Inyo, California
Tech details404 KB. Outcrop.
GeoDIL number561