working-with-rocks:My favourite road cut. A welded tuff on the highway between Shoshone, Calif
working-with-rocks:My favourite road cut. A welded tuff on the highway between Shoshone, California and Pahrump, Nevada. There’s a good parking area across the road.This rock erupted out of a volcano as ash. It landed on the ground as a thick pile of still hot ash - the heat in it was enough to allow the ash to re-cross its glass transition to act like a liquid, then it cooled to a glass as the heat escaped. -- source link
#geology#igneous#volcanic#science#nature#california#desert#obsidian