We’re Wrong About How Mountains Form

We think we know how mountains form. Plate tectonics causes rock to be pushed up at fault boundaries. Except that model is hard to prove, and a new study suggests it might actually be a lot more complicated.

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Sources:

[HalfBewolktBestondAl]

I'm a geochemist working a project studying the Italian subduction zone, specifically the influence of subducted sediments on the Italian volcanic products. Some claims in the video are a bit more nuanced; at 1:01, it is suggested that asthenospheric convective currents drive the movement of plates. This is a common misconception, but the actual primary drivers of plate movement are ridge push and slab pull (the latter of these is shown in the diagram, but not in the correct spot). Both are gravitational forces acting on the plate, at the MOR and subduction zone respectively. Later in the video, it is claimed that dynamic topography is only suggested from computer models, but never observed in nature. However, dynamic topography can be observed as a subtle bulge surrounding oceanic islands above mantle plumes. Lastly, another important factor dictating the rate of uplift during mountain building phases is actually erosion! The unloading caused by erosion during orogenesis has a tremendous effect on the rate of uplift. As erosion rates are controlled by climatic changes, this also results in changes in uplift rates, independent from the rate of subduction.

[fumfering]

I love this! Anybody who's watched anything that flows has seen (but perhaps dismissed) how complex the action is, so it's always been clear to a careful observer that tectonic plate movements are more interesting than the simplistic model presented in a Geology 101 class. So it's not that geologists were wrong; it's that they went with a simplistic model, which is the way most scientific models start out. Sounds like the next generation of scientists are going to live in interesting times!

[nothanks]

I think it's important for people to remember that plate tectonic theory has only gained widespread acceptance since the late 1960's. So we're still in the process of refining and perfecting the various aspects of the theory and that has rapidly increased in the last 20 years with improving sensor technology and techniques such as more advanced geophysical technology and methods.

[mashrurrashid]

Tectonic plate theory

Convergent Boundaries: The most frequent way that mountains form is when tectonic plates collide. Mountain ranges can be created when two tectonic plates collide and push against one another, lifting the crust. The Himalayas, Andes, and Rocky Mountains are all the result of this kind of mountain formation.

Tectonic plates are forced beneath one another in subduction zones, where there is a great deal of pressure and friction. As a result, volcanic mountain ranges like the Cascades in the Pacific Northwest may form.

[Celeste-in-Oz]

From now on, ‘mountain chains’ will be referred to as ‘rocky pool floaties’. Thank you.

[nertia]

I love when what we "know" turns out to be wrong - it shows that science is always evolving and that we will never stop learning 😃

[The_Opinion_of_Matt]

Or maybe slower subduction is a sign of higher friction between plates and the higher friction results in more of the top layer of rock being scraped off. Conversely, faster subduction could be the result of less friction resulting in less of the top layer of rock being scraped of. Like taking a course file to the edge of a metal cube. Light pressure on the file results in smaller shavings coming off the metal block and file sliding smoothly across the edge. High pressure on the file results in larger shavings coming off the metal block and the file moves slowly across the edge.
I'm not saying the researchers are wrong, just proposing a different possibility.

[Caracal-lmes]

"Things might not always be as simple as we imagined"

What a surprise! 😉

[skybluskyblueify]

Some people are uneasy about uncertainty and updating ideas as new info comes in. They want it to be written in stone and unchanging so they won't feel off balance on what is reality and what is not reality. Why aren't kids taught that this is how science works rather than taught a list of unchanging "facts"? That way they will be less likely to panic when, let's say, ideas about plate tectonics seems to change?

[CathodeRayKobold]

In retrospect, it seems kind of obvious that fluid dynamics is as complicated on a continental scale as it is on a human one.

[outlawbillionairez]

There's mountains forming on my front lawn. Connected by small geological tunnels! At this rate of growth, there'll be a full mountain range soon.😮

[DanH-uf]

They are formed by plate tectonics. This is fact.

[DANGJOS]

This makes more sense. I was never very knowledgeable about this, but I always found the conventional explanation to be unconvincing. Whenever we oversimplify complex processes in nature, we are often wrong.

[huw]

So it's not so much that the model is wrong - but there are some added refinements to our understanding of a complex process.

[Mithrandir]

I can think of a different explanation that does not change the way we think of mountain building.

If subduction is fast, then the 2 plates are not "catching" on each other and therefor there is little mountain building. Likewise, if subduction is slow that is because the plates are "catching" this time and it is causing the upper plate to buckle and build up the mountains.

Seems to make sence to me.

[IAmWillIAmWill]

You should look into Arthur Posnansky's work on Tiahuanaco. He did considerable research into the land rises in that area among many other things.

[MegaAstroFan]

Doesn't really mean we're "completely" wrong about how mountains form, just that our view was overly simplistic.

[dgblitwin]

Funny, I was just talking with the lead author of this study today. Great to see this work getting some public coverage!

[DenizenoftheAges]

I mean - slow progress means longer melting and more concentrated temps.
Any baker would tell you this is equal to how "gooey" a cake is vs how it bakes.
Edit: Geography/Geology graduate.

[edwardhanson]

And convergent plates don't all interact the same way. Some descending slabs dive down, some slide along the underside of the out crust.