Panum Crater

Panum Crater in eastern California is one of the youngest volcanoes in the Mono–Inyo chain and a classic example of a rhyolitic lava dome. Formed about 600 to 700 years ago, it developed in stages: a steam-driven explosion blasted out a broad crater, falling ash and pumice built a ring around the vent, and thick silica-rich magma then rose slowly into domes whose surfaces shattered into crumble breccia. The volcano produced abundant pumice and obsidian, the latter used by Native Americans for tools. Its flow banding, breadcrust textures, and scattered dome-top debris make it an especially clear record of how gas-rich, sticky magma erupts and cools.

California · United States