What drew my attention, though, wasn't the story as much as the lead photo. Any geology types have an idea what we're looking at? I'm guessing it was a lava tube or flow; those radial columnar joints suggest a circular outline, at least on the bottom. The bedrock is somewhat obscured by moss and plants above the midline of the structure, and I can't tell from the picture whether the radiating joints continue to make a full circle. Whatever it is, I like.
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Cool pic! The columnar jointing in basalt sometimes baffles me - maybe it is a filled-in lava tube.
Prepare to make myself look foolish
Is it certain we're looking at basalts? The fracture patterns look more like cleavage in a shale than jointing to me - perhaps it could be a fold hinge?
No, Chris, it's definitely basalt - probably ~17 Ma Columbia River Basalt. I think Silver Fox's idea is a possibility. If I recall correctly, the CRB flows were quite thin and inflated with lava tubes, which allowed them to travel such long distances from their sources. But I'm not a petrologist...
Anyways, it's a beautiful picture, Lockwood.
I'm confident it's basalt. There are some marine seds interbedded with CRB in the W. Cascades (the Willamette Valley was an embayment at the time), but they tend to be nearshore, and strongly bedded. No massive shales that I know of. There is some gentle folding in the region, but I don't think you could get that feature from deformation. The sharp cutoff on the lower left suggests a minor fault to me.
As I noted in the post, this is from the news... I don't really have any idea where it is. But I agree with Anne: it's strikingly beautiful.
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