
This picture isn’t great (I’m still getting the hang of my new camera) but this is a petrified tree trunk in a cave. Over the weekend, Chuck took me up to a secret spot he found a few months ago where there is a lot of petrified wood, and a number of these big tree trunks either hanging on the cliffs, or inside of erosion caves like this one.
I promised I wouldn’t tell exactly where it is, but it was a lovely afternoon hike while big thunderstorms blew across the Paradise Valley. There was just enough cloud cover to keep us from getting too hot, although we did hit one bad stretch through a high swampy seep where the bugs were enough to drive a person mad.
It’s hard to tell what the geology was here exactly. Somehow the term pyroclastic flow bubbled up from the depths of my brain where my college geology info is stored (Beloit had a particularly fabulous geology department). And from checking Wikipedia it looks like that could have been what happened — an eruption out of Yellowstone that engulfed some big trees in volcanic dust and rock. I loved geology — I couldn’t do the math but the language is so lovely.
Postscript: My biologist friend sent this along: “I showed your blog photo to Josh, the geologist who works for me who got his degree at MSU. He said an actual pyroclastic flow is unlikely to produce a petrified tree, since those flows are usually at 2,000 degrees which will (here’s where the biology PhD comes in handy) incinerate a tree. But a mud flow from a nearby volcano is likely. The mud flows are not so hot and would flow around the standing tree. That’s how the Petrified Forest in Tom Miner basin formed.”
Geology
I know the origin of rocks, settling
out of water, hatching crystals
from fire, put under pressure
in various designs I gathered
pretty, picnic after picnic.
And I know about love, a little,
igneous lust, the slow affections
of the sedimentary, the pressure
on earth out of sight to rise up
into material, something solid
you can hold, a whole mountain,
for example, or a loose collection
of pebbles you forgot you were keeping.
–Robert King
Reprinted from the Marlboro Review, Issue 16, 2005, by permission of the author. Copyright (c) 2005 by Robert King, whose prose book, “Stepping Twice Into the River: Following Dakota Waters,” appeared in 2005 from The University Press of Colorado.
Wow! Thanks Patrice!