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Tom Mazanec
2017-Jan-02, 02:45 PM
Where would a plausible next flood basalt be located?

Trebuchet
2017-Jan-02, 04:43 PM
Based on Wikipedia (https://en.wikipedia.org/wiki/Flood_basalt), my neck of the woods seems to have had the most recent ones. Rare events in any case, however.

I drive through the Columbia River Basalts (https://en.wikipedia.org/wiki/Columbia_River_Basalt_Group) several times a year and never fail to be impressed. Equally impressive is how water has worn through them, sometimes rather quickly (https://en.wikipedia.org/wiki/Missoula_Floods).

Tom Mazanec
2017-Jan-02, 04:57 PM
I first learned about these in the Sixties, when I read a scifi short story about a man in England who hears of them from a visiting American geologist (he calls them "fissure flows"). Later that day, England is destroyed by a fissure flow, and the man is one of the few survivors.

geonuc
2017-Jan-03, 10:10 AM
Iceland, for one, I would think.

Plausible identifiable future flood basalt regions would be where rifting is occurring in conjunction with a mantle plume. Unidentifiable regions would be those where massive volcanism is caused by an impact.

grapes
2017-Jan-03, 04:59 PM
Iceland, for one, I would think.

Plausible identifiable future flood basalt regions would be where rifting is occurring in conjunction with a mantle plume. Unidentifiable regions would be those where massive volcanism is caused by an impact.

There is a list at this wikipedia article:
https://en.wikipedia.org/wiki/Flood_basalt

The North Atlantic Igneous Province (NAIP) (which includes areas that broke up and ended up scattered in the North Atlantic, from Ireland to North America) was 56 million years ago, and is associated with the hotspot at Iceland today. More recent than the Columbia River Basalt Group ( 17mya, Yellowstone hotspot), is the Canadian Chilcotin Group from 10mya.

ETA: I'm thinking the Cameroon Line, as a future flood basalt region, is a fifty-fifty bet. Is there a mantle hotspot associated? Maybe, maybe not.
https://en.wikipedia.org/wiki/Cameroon_line

geonuc
2017-Jan-04, 09:39 AM
ETA: I'm thinking the Cameroon Line, as a future flood basalt region, is a fifty-fifty bet. Is there a mantle hotspot associated? Maybe, maybe not.
https://en.wikipedia.org/wiki/Cameroon_line

Yes, depending on the presence of a mantle plume. If no plume but the lithographic fracture notion is correct, then perhaps this area would make a plausible candidate for impact-induced flood basalts.

bknight
2017-Jan-04, 02:22 PM
There is a list at this wikipedia article:
https://en.wikipedia.org/wiki/Flood_basalt

The North Atlantic Igneous Province (NAIP) (which includes areas that broke up and ended up scattered in the North Atlantic, from Ireland to North America) was 56 million years ago, and is associated with the hotspot at Iceland today. More recent than the Columbia River Basalt Group ( 17mya, Yellowstone hotspot), is the Canadian Chilcotin Group from 10mya.

...
The Yellowstone hotspot is nearing a historical time frame eruption. When this occurs most of the US will be in for a environmental shock. I'm not suggesting an immanent eruption, but it has been 640 K years since the last.
http://www.yellowstonepark.com/explore/volcanos/

geonuc
2017-Jan-04, 10:51 PM
The Yellowstone hotspot is nearing a historical time frame eruption. When this occurs most of the US will be in for a environmental shock. I'm not suggesting an immanent eruption, but it has been 640 K years since the last.
http://www.yellowstonepark.com/explore/volcanos/
I'd be careful in attributing too much weight to periodicity of the Yellowstone volcano. This isn't Old Faithful. When you consider geologic time, conditions change quite a bit. The mantle plume evolves and the North America plate moves. It may well be that the hotspot produces no further massive eruptions.

grapes
2017-Jan-05, 03:42 AM
I'd be careful in attributing too much weight to periodicity of the Yellowstone volcano. This isn't Old Faithful. When you consider geologic time, conditions change quite a bit. The mantle plume evolves and the North America plate moves. It may well be that the hotspot produces no further massive eruptions.
The datings have moved around a bit over the last twenty years. Right now, it looks like 2.1mya,1.3mya,.64mya, so the average of the two is .73my ((2.1-.64)/2), and the most recent being .66my (13-.64), but the one before that was .8my, so it might be getting shorter. That third possibility is where we might have to worry. :)

These are not flood basalts though. They're big eruptions, but not of the Mt St Helens type either.

bknight
2017-Jan-05, 03:37 PM
The datings have moved around a bit over the last twenty years. Right now, it looks like 2.1mya,1.3mya,.64mya, so the average of the two is .73my ((2.1-.64)/2), and the most recent being .66my (13-.64), but the one before that was .8my, so it might be getting shorter. That third possibility is where we might have to worry. :)

These are not flood basalts though. They're big eruptions, but not of the Mt St Helens type either.

Yes it will be a big eruption if/when it happens, but I don't think you can automatically negate a flood basalt once the magma chamber is exposed to the surface.

grapes
2017-Jan-05, 04:47 PM
Yes it will be a big eruption if/when it happens, but I don't think you can automatically negate a flood basalt once the magma chamber is exposed to the surface.
Of course. I think. :)

I was just pointing out that the historical eruptions, which fuel the speculation about an imminent eruption, are not flood basalt incidents.