<p>I think there are two aspects to consider.</p>
<ul>
<li>Before moving away when a supercontinent breaks up, plates have to collide to form this supercontinent in the first place. This process, called an orogeny, builds mountains. And mountains take a long, long time to erode. For example, the <a href="https://en.wikipedia.org/wiki/Variscan_orogeny" rel="nofollow noreferrer">Variscan orogeny</a> happened when Laurussia and Gondwana collided to form Pangaea. This formed many mountains that still exist today, in Europe (French Massif Central, Bohemian Massif...) or in North America (Appalachian). Breaking up the supercontinent doesn't mean that you erase the mountains that were formed when the supercontinent formed. So <strong>even if plates move away, you keep old mountains</strong>.</li>
<li>When plates move away from a broken supercontinent, they can eventually meet and collide. For example, when Pangaea broke up, Asia and India both moved away, but at some point Asia began to move North and collided with Asia, forming the Himalayas. So <strong>even if plates move away, they can collide and form new mountains</strong>.</li>
</ul>
<p>Supercontinents actually follow <a href="https://en.wikipedia.org/wiki/Supercontinent_cycle" rel="nofollow noreferrer">a cycle</a> of formation and breaking up, and both phases can lead to mountain building.</p>

CC BY-SA 4.0
2022-09-03T20:26:21.450Z
2022-09-03T20:26:21.450Z
Jean-Marie Prival
<p>Please correct me if I have said something wrong, as it might be the answer to my question. Also, these are all the things that I've learned through self-studying, so I might have been mislead.</p>
<p>Anyways,</p>
<p>The plate tectonics theory states that the Earth's lithosphere have been and is still (slowly) moving since about 3.4 billion years ago. It is proved by many evidences, most notably global distributions or locations of volcanoes, earthquake epicenters, and mountain belts. When superimposed, these locations somewhat forms the plate boundaries of a proposed supercontinent pangea.</p>
<p><a href="https://i.sstatic.net/u9O9a.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/u9O9a.png" alt="enter image description here" /></a></p>
<p>Photo credits: <a href="https://www.learner.org/wp-content/interactive/dynamicearth/tectonicsmap/index.html" rel="nofollow noreferrer">https://www.learner.org/wp-content/interactive/dynamicearth/tectonicsmap/index.html</a></p>
<p>From my understanding, volcanoes, earthquake epicenters, and mountain belts are all the products of colliding plates.</p>
<p>If this is so, and if it is true that the plates moved somewhat <em>away</em> from each other (since it was once a supercontinent, then it is now <em>scattered</em>), then why is it that there are volcanoes, earthquake epicenters, and mountain belts--products of collision--in areas where a collision didn't happen?</p>
<p>Like, the plates moved away right? And collision, from my understanding, is the <em>crashing</em> of two plates, and collision ≠ moving away. So why is it that they formed despite no plates collided to each other?</p>

<geophysics><plate-tectonics><tectonics>
Why are the supposed-to-be results of collision and/or subduction formed in an area where collision and/or subduction didn't happen?
Harvey
# Why are the supposed-to-be results of collision and/or subduction formed in an area where collision and/or subduction didn't happen?

(Asked by: username_0 on 2022-09-03)

Please correct me if I have said something wrong, as it might be the answer to my question. Also, these are all the things that I've learned through self-studying, so I might have been mislead.

Anyways,

The plate tectonics theory states that the Earth's lithosphere have been and is still (slowly) moving since about 3.4 billion years ago. It is proved by many evidences, most notably global distributions or locations of volcanoes, earthquake epicenters, and mountain belts. When superimposed, these locations somewhat forms the plate boundaries of a proposed supercontinent pangea.

[![enter image description here](https://i.sstatic.net/u9O9a.png)](https://i.sstatic.net/u9O9a.png)

Photo credits: <https://www.learner.org/wp-content/interactive/dynamicearth/tectonicsmap/index.html>

From my understanding, volcanoes, earthquake epicenters, and mountain belts are all the products of colliding plates.

If this is so, and if it is true that the plates moved somewhat *away* from each other (since it was once a supercontinent, then it is now *scattered*), then why is it that there are volcanoes, earthquake epicenters, and mountain belts--products of collision--in areas where a collision didn't happen?

Like, the plates moved away right? And collision, from my understanding, is the *crashing* of two plates, and collision ≠ moving away. So why is it that they formed despite no plates collided to each other?

**Tags:** geophysics, plate-tectonics, tectonics


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## 1 answers

### Answer by username_1 on 2022-09-03. Score: 2 | Accepted answer

I think there are two aspects to consider.

* Before moving away when a supercontinent breaks up, plates have to collide to form this supercontinent in the first place. This process, called an orogeny, builds mountains. And mountains take a long, long time to erode. For example, the [Variscan orogeny](https://en.wikipedia.org/wiki/Variscan_orogeny) happened when Laurussia and Gondwana collided to form Pangaea. This formed many mountains that still exist today, in Europe (French Massif Central, Bohemian Massif...) or in North America (Appalachian). Breaking up the supercontinent doesn't mean that you erase the mountains that were formed when the supercontinent formed. So **even if plates move away, you keep old mountains**.
* When plates move away from a broken supercontinent, they can eventually meet and collide. For example, when Pangaea broke up, Asia and India both moved away, but at some point Asia began to move North and collided with Asia, forming the Himalayas. So **even if plates move away, they can collide and form new mountains**.

Supercontinents actually follow [a cycle](https://en.wikipedia.org/wiki/Supercontinent_cycle) of formation and breaking up, and both phases can lead to mountain building.


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