Last summer I wrote a post about hiking at Blue Basin, an incredible rock formation in nearby John Day Fossil Beds National Monument. When I was there before, I took the loop trail that circles the whole thing, but recently I went back to check out the shorter trail that takes you into the blue-green canyon itself.
If first guess for what causes the amazing color of the rock is copper, well, you’re not alone; that’s what I would have thought, too. However, it actually comes from the weathering of obscure minerals called celadonite and clinoptilolite, both part of the volcanic ash deposits laid down in this area by ancient volcanoes. (Like I said in my last post: my understanding of the geological history of this region boils down to “volcanoes, woot!”)
If, for some strange reason, you ever find yourself driving Highway 26 through eastern Oregon, the Sheep Rock unit of the John Day Fossil Beds is definitely worth a stop. In addition to Blue Basin, there’s a great visitor center with a lot of interesting fossils on display.
Photos in this post by Evan Heisman.
Tagged: blue basin, geology, john day fossil beds national monument