This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
PSM Exposed section of lava stream on the side of river ardeche. Exposed section of lava stream on the side of River Ardeche archive org Popular Science Monthly Volume Author PDold Popular Science Monthly illustrations Volcanic rocks Volcanoes of France Lava flows in France Columnar basalts of France in France Diagrams of lava