ancient volcanism

I'm still playing catch-up after my week in the desert, so I've seen a lot of articles I've wanted to mention ... but a certain other volcano has taken up a lot of my time. However, I will attempt to make amends for that now. By the way, would you believe Ubehebe Crater was closed? How do they close a volcano, anyway? However, I did get a great snap of a welded tuff on the road outside of Shoshone, CA. A strongly welded tuff near Shoshone, CA. The dark interior is remelted volcanic ash/tephra surrounded by less welded pink tuff with abundant pumice clasts. Denison student David Sisak is on…
Chaiten in Chile erupting in January 2009. Even after over a year of activity, Eruptions readers are still captivated by the volcano. Thanks for sending me your questions about volcanoes and volcanism. I'll try to tackle some hear - but as always, keep the questions coming! Send them to For those of you who have submitted a question but don't see the answer here, do not fret. Likely it just means that I needed to do a little more research into the question and will get to it in a later mailbag! So, without further ado ... Mark M.: Here in the Appalachians we have very dense crystalline rock (…