Thanks gleeaikin and BenLurkin.
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Posted on 03/28/2016 7:12:55 PM PDT by BenLurkin
Up to 12 massive volcanic blasts occurred between 8 million and 12 million years ago in Idaho's Snake River Plain, leading up to today's Yellowstone supervolcano, new research reveals.
A dozen of these ancient supereruptions took place along the Yellowstone hotspot track, researchers reported Feb. 10 in the journal Geological Society of America Bulletin. The trail of eruptions marks where the North American tectonic plate sailed over a superhot blob of mantle rock called a hotspot. (The mantle is the rocky layer between Earth's crust and core.)
Though learning of more supereruptions in the West may seem unsettling, the findings do not suggest that Yellowstone today is any more hazardous than previously suspected. Instead, the researchers said they are now studying whether Yellowstone is actually dwindling in strength compared to the larger and more violent eruptions that occurred 12 million years ago.
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Until now, geologists did not have a firm count of the number of eruptions in Idaho and surrounding states that predate Yellowstone, nor a good estimate of the size of each outburst. The new study suggests there are fewer volcanic eruptions in the central Snake River Plain than previously believed. However, the 12 recorded giant eruptions were likely "significantly larger" than other studies suggested, the researchers said.
The craters formed by these giant eruptions are now buried under sediment and younger lava flows. To better understand past eruptions, Knott led an international team of volcano experts in analyzing the many layers of lava plating central Idaho. The researchers fingerprinted different eruptions by testing for changes in the chemical makeup of the rocks and the rocks' magnetic orientation. (Every volcanic eruption produces lava with a unique chemical makeup.) The team correlated these volcanic deposits across hundreds of miles (thousands of kilometers).
(Excerpt) Read more at livescience.com ...
They were Yuuuge!
It’s really an interesting drive through Eastern Oregon/Southern Idaho toward Wyoming. It’s a volcano natural museum. Just don’t take the drive in the winter!
The ash would be good for the soil.
I need to do some wondering in that direction.
We have been in Yellowstone more than a dozen times and now go annually again since we retired and bought a 5th wheel RV.
If the caldera blows I would just as soon be there.
Today I drove (again) on the highway between East Wenatchee, and Quincy, WA in the deep gorge created by the Columbia River. The north side of this river valley displays an incredible continuous cliff of multiple layers of volcanic eruptions over the millennia. Right next to the highway. If you are interested in geology, (I am) this drive is spectacular. Central WA State is loaded with these kinds of geological marvels.
It’s mostly high desert (which I like) but it’s accessible to the Saw Tooth Mnts and Salmon River which have their own unique geology and great fishing. The volcanic trail north of the Snake as well as the gorge of the Snake are unique. Craters of the Moon National Monument is something else. Invest a little time in it.
I’ve been through the “scablands” and Columbia Gorge a few times. It’s hard to get a mental picture of the Missoula floods until you see what’s left of the flood basalt that was in the way.
Thanks for the info.
I like high deserts also as long as I can follow a river.
Especially along the Snake.
“Craters of the Moon National Monument is something else. Invest a little time in it.”
I’ve always meant to do that, but haven’t made it yet. Sounds like a fantastic route for a meaningful motorcycle trip. On my list.
http://www.iafi.org/floods.html
The above is a link to society for the ice age floods. As you head south to Hanford from Vanatage, when you go south across the river and then up that steep hill, look back to the north and there is a huge ridge (100 feet+ tall?) along the north side of the river that is an old sand bar.
I did a job near the mouth of the Columbia river. It was all basalt rock about 20 feet down, acres of basalt. They drilled down and after 200 feet or so they hit soft sand. (Not sandstone rock!) Not sure how that works!
Here is a site with images of what is called the Picabo Chain which currently ends at Yellowstone after 12 million years. There are also many other volcano and earth images and for some weird reason hamburgers, and other food stuffs.
This article was written by a geologist who has studied the Picabo Chain. He suggests that another super eruption may be a million years away. Smaller ones can occur as has happened about 70 times since the last big one of 640,000ya.
Thanks gleeaikin and BenLurkin.
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