A geologist examples a basaltic lava flow along the Madison River
By Yellowstone Volcano Observatory
June 2017 (approx.)
![A geologist examples a basaltic lava flow along the Madison River](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/media/images/Madison%20River%20Basalt.jpg?itok=7vomFxm4)
Detailed Description
A geologist examples a basaltic lava flow along the Madison River, looking for an area that can yield samples suitable for 40Ar/39Ar geochronology. USGS photo by Jorge Vazquez, June 2017.
Sources/Usage
Public Domain.