Categories: Arizona, canyons, Environment, Geology, Grand Canyon, National Parks, Photos, rocks, Travel
Photo: Steep rugged cliffs above the Colorado River at sunset, Toroweap, Grand Canyon National Park, Arizona
When you look at images of the Grand Canyon and you have any basic sense of geology, you think about eons of huge yet subtle geological forces at work, namely the continually erosive power of water slowly carving its way through layer after layer of sedimentary rock. But you probably don’t think of volcanoes. Here in the United States, volcanoes are for places like Yellowstone, or the Cascade Range in the Pacific Northwest, with Mount Rainier and Mt. St. Helens, even here in California with Mount Lassen, Mount Shasta, and the Long Valley Caldera. But the Grand Canyon and volcanoes? Nope, this combination does not automatically compute.
When I’m hanging out in my living room working on my laptop, I may have the television turned on as background noise to the History or Science Channels, PBS, or the local news. The other day I caught an episode of How the Earth Was Made on the History Channel. I’d previously seen a great episode they had on the formation of Yosemite Valley, so I paid a little more attention than usual when I caught an episode on the formation of the Grand Canyon.
Needless to say, I was a little surprised when they started talking about lava flows at the Grand Canyon, with some surface flows dating to as recently as within the last thousand years or so. Even more surprising was when the pointed out a lava flow formation that could be seen near Toroweap on the north rim. Hey… I’ve been there; let me check my photos. So I went back into my archives and found this image from my visit in October 2006, and sure enough, right in the middle of Read the rest of this post »