At 11:10 AM 5/17/2002 -0700, you wrote:

>I could imagine that could also happen in the wild if a ton of leaves or
>something collected in a crevasse, after a while it could go poof!

I have never seen anything like that, but I know that my grand father used 
to keep a compost heap when I was a kid.  If he didn't keep turning it 
regularly it would start smoldering.  I would think that it would be the 
same idea.


Scott
Team My Blue Heaven
www.myblueheaven.com/geocache