Ancient Tectonic Plates discovered beneath Earth's current Tectonic Plates?

Hello ATSers,

Please read the article linked here: www.iflscience.com...

The article clearly states the research has not been peer reviewed as of yet, but the research and results are quite interesting, and opens the door for multiple theories and alternative ideas as to how and when our Earth came to its current form.

Movement from beneath our current Tectonic Plates has been hypothesized to be the cause of some extremely deep originating earthquakes. I know I believed, and I was taught, that once Plates subducted they turned into molten lava, most likely. This article suggests that some more dense Plates remain intact, and have existed for quite some time.

I look forward to more from peer revision to clarify, support/debunk this research.

It's not necessarily that they are ancient. Deep seismology analysis has revealed that there are ancient inactive tectonic plates that are crumpled up inside the mantle. They were pushed down and underneath existing crustal tectonic plates.

Now we have a second set of tectonic plates that seem to be on the underside of the convection currents that move the surface tectonic plates.

Granites and other igneous rocks come from sedimentiary layers that get baked by the heat of the mantle.

To me this makes logical sense as a solution for ultra deep seismicity. That was one thing I never understood either, how a quake could occur at 600+ km depth. But with this new research, the cat is out of the bag.

As a side thought to this, it may offer an additional explanation for why over the geologic eras, volcanism- and especially Continental Flood Basalt type volcanism- has disappeared or decreased. That additional boundary layer of deep plates is sealing off the escape routes for magma in a large percentage of the upper layers. They will probably find that areas that still have active volcanism fall in the areas where there is no second deep plates, or there are gaps.

Good find and interesting article, S&F!

a reply to: Boscov

Our planet's plate tectonic system is purely fascinating.

A well documented example is the ancient Farallon plate, an oceanic plate that has subducted under the western part of the America's, specifically, North America.

Farallon plate info


Great thread on a topic that is receiving the resesarch it deserves.

Could this explain how we have unexplained earth tremors in England when we're about 1000 miles from the nearest tectonic plate edge?

So the romans were right fearing "the sky will fall down on us"! I knew it. History repeats.

originally posted by: Imagewerx
Could this explain how we have unexplained earth tremors in England when we're about 1000 miles from the nearest tectonic plate edge?

In the last Ice Age, the ice sheets pushed the North of the country downwards into the mantle, and actually twisted/tilted the entire UK so that the South of the country was pushed upwards. Now, with the ice sheets gone, the country is gradually tilting back. The South of England is actually sinking.

www.bgs.ac.uk...

a reply to: TrueAmerican

As someone who seems to know a stone from a rock, do you think this might account for the postulated cratons that fuel systems such as Yellowstone, Cascadias and Iceland?

a reply to: stormcell

Post-glacial isostasy!

Deep plates probably exist and possibly wafer-like plate layers
exist. These are all suspended in the molten minerals from the
inner mantle to the outer core. This suspension is immense that
spans the distance from the two and it must be layer upon layer
of particular mixes of elements.

a reply to: TrueAmerican

originally posted by: Revolvacron
a reply to: TrueAmerican

As someone who seems to know a stone from a rock, do you think this might account for the postulated cratons that fuel systems such as Yellowstone, Cascadias and Iceland?

Do you understand what a craton is? A craton is a large more or less stable area of continental rock, so I don't know what you are talking about, unless you are trying to refer to hotspots, and got the two terms mixed up. Hotspots fuel the YS, Hawaiian, and Icelandic volcanic systems, as well as others.

And interestingly, just FYI, the North American stable continental craton runs nearly right down the middle of Yellowstone, diagonally. And if I remember right, scientists believe some kind of large slab is blocking the caldera's magma chamber from refueling, at least to a partial degree. This would explain why there is such a small melt ratio, and also why scientists like Jake Lowernstern, director of the YVO, believe YS is "finished."

originally posted by: Revolvacron
a reply to: TrueAmerican

As someone who seems to know a stone from a rock, do you think this might account for the postulated cratons that fuel systems such as Yellowstone, Cascadias and Iceland?

Yes.

The Juan de fuca subduction zone fuels and created the Cascadia volcanic region. That plate is a direct remnant of the Farallon plate that now lies beneath North America.

originally posted by: CreationBro

originally posted by: Revolvacron
a reply to: TrueAmerican

As someone who seems to know a stone from a rock, do you think this might account for the postulated cratons that fuel systems such as Yellowstone, Cascadias and Iceland?

Yes.

The Juan de fuca subduction zone fuels and created the Cascadia volcanic region. That plate is a direct remnant of the Farallon plate that now lies beneath North America.

Farallon plate is not what we can now see for, much like Wegener's Pangea, most of it has subducted beneath North America. It's only parts that still remain exposed are the micro-plates (?) 'Juan de Fuca' and 'Cocos'.

Source

originally posted by: stormcell

originally posted by: Imagewerx
Could this explain how we have unexplained earth tremors in England when we're about 1000 miles from the nearest tectonic plate edge?

In the last Ice Age, the ice sheets pushed the North of the country downwards into the mantle, and actually twisted/tilted the entire UK so that the South of the country was pushed upwards. Now, with the ice sheets gone, the country is gradually tilting back. The South of England is actually sinking.

www.bgs.ac.uk...

I seem to remember reading the last glacier to visit England only got as far South as Luton.It must have got stuck in the roadworks on the M1.

This is a good 3D view of where the Farallon plate is now:

upload.wikimedia.org...

There are internal convection currents running inside the inner core (iron/nickel). These drive another set of convection cells in the mantle. The remains of the Farallon plate look like the debris from a bullet wound.

a reply to: TrueAmerican
I do, I was curious as to whether this might be an alternative explanation for their origins. At least in Iceland's case, the last I had read, it was still undecided by which mechanism was everything was driven by. Hadn't heard that about Yellowstone, will check it out.