Tuff from Crater Lake eruption, Oregon


I collected this miles from Crater Lake back in the mid-1990s.  The tuff globs are abundant, and I’m sure there is a size stratification, with the larger masses closer to the site of the eruption.  Everyone should have a glob of tuff, just to startle friends through a quick toss.  When I did my Masters work in Guatemala with two other friends (Tom Anderson, Alston Boyd III), one of us would occasionally pick just the right moment (e.g., during a stream crossing) and loft a boulder of pumice at a field partner.  

Age & Formation
7700 years B.P., a product of the Mt. Mazama eruptions and formation of Crater Lake caldera.