High school and geology

A reminder just showed up in my inbox of a message that I never actually received through my high school alumni website. The message was sent three years ago. Cyberspace is weird and wonderful.

I have never been back to my high school and never seriously considered going. I suppose if I still lived in town I would have gone to some alumni events, even though I only had a few friends in high school, but as it is I live far away and my friends and family are no longer in that town (Charlottesville Virginia).

I was warned yesterday that I'm going to be interviewed by some college students about how we know the age of some rocks the state. That won't be a problem, but it might be a challenge to make the answer seem interesting. It is for a documentary film that they are making. Because the answer is that some spores whose age we know showed up in the rocks in Alabama and some shells whose age we know showed up in the rocks in Alabama; I will be hard-pressed to set the blood pumping faster with that. Of course, ultimately, we know the ages because of volcanoes! Volcanic ash beds and ancient lava flows can be dated using unstable isotopes. That's where all of the absolute ages come from.