Interesting stuff Roger. Some believe that, given (a lot of) time, the current event in Iceland may lead to the formation of a shield volcano.
I'd be afraid to go near an active vent, DrM. A lava flow is sufficient for thrills, though given the opportunity to look into an active crater I'd still be tempted!
We often used to find leaf casts and other plant material the deposits on the Island and I'd have debates with my students are to whether such rocks were igneous or sedimentary.
One of our former pupils was in charge of the recent evacuation and was kind enough to keep me up to speed - very interesting.