[Rockhounds] fulgurites

[pmodreski at aol.com]

You're right, Earl, there are lots* of rock fulgurite pictures posted on the www; and I think I do remember you telling us before, about those you had seen on Humphrey's Peak.

*Well, maybe not "lots".? When I Google "rock fulgurites" images, a lot of pictures come up, but most of these are still of regular (sand) fulgurites.? I think I only see two bona fide rock fulgurites pictures there online; one of a melted patch on rhyolite from Shastina, California (posted?on geology.about.com), and another of a thin melted tube on the surface of quartzite from Mt. Raymond, Wasatch Range, Utah, posted as an article by the Utah Geological Survey.? I really don't think that any of the other pictures that came up, are actually fulgurites on or in rock.? The Utah article notes that,
"Some of the rock fulgurites, such as those found on Mount Timpanogos, are the result of human activity (a steel shelter placed on top of the peak attracts lightning)."

I think a real "rock fulgurite" is still a pretty rare bird.

Earl, if you ever "dig up" those specimens you collected in AZ, I'd love to see you post a picture of them!

Pete


-----Original Message-----
From: Earl R. Verbeek <everbeek at ptd.net>
To: rockhounds at lists.drizzle.com
Sent: Tue, 16 Sep 2008 11:37 am
Subject: Re: [Rockhounds] fulgurites



Hi Pete,

Years ago I collected some rock fulgurites from the summit area of
Humphrey's Peak near Flagstaff.  Melted andesite, mostly.  In some areas
you can see where the molten skin of rock forms "tendrils" that obviously
followed little streams of water as they flowed on the rock -- that is, the
fulgurites follow drainageways as the rock first starts to become wet
during a rainstorm, and then lightning hits the rock.  Pretty neat to see
these pathways.  There are some nice photos of rock fulgurites on the web,
too.

              Cheers-   Earl




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