Was Long Valley Volcano explosive or nonexplosive?

Question

AND HOW DO YOU KNOW!!!!!

Answer 1

The eruption that produced the Long Valley caldera about 700,000 years ago was definitely explosive. Earlier eruptions were not particularly explosive, producing basaltic and andesitic flows mostly. Subsequent eruptions have also consisted primarily of rhyolitic flows for the most part, with some expulsion of Tephra, and have not been particularly explosive. Here's a great link if you'd like to read up on it a bit more:

http://volcano.und.nodak.edu/vwdocs/volc_images/north_america/california/long_valley.html

How do I know? Hmmm... I'm a geologist. I've visited the area and seen the caldera. It's quite impressive! Volcanism in general is an interesting subject.

Answer 2

The Long Valley caldera is HUGE - this indicates to me that it would have been a massive (explosive) eruption. There are composite volcanos along the rim of the caldera, and composite cones are formed from explosive eruptions (less violent eruptions create shield volcanos like the Hawaiian islands).

I had never heard about the Long Valley caldera before, so I'm just learning about this myself. Here is a website for you to look at if you want more detailed information.

GEOLOGY RULES

EDIT:
Just noticed that GatorGal had already given a much better answer than mine, and had also given you the same link. Oh well... I tried.