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Mike2220 t1_jb2ridj wrote

Realistically, whatever plate is following behind the sinking plate would just become the new subduction zone with whichever plate was initially going over. Also there would be a lot of mountainous terrain formations and seismic activity as islands/continents would literally have been shoved together during this process

This has happened before if you'd like to read more specifics

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sth128 t1_jb326bd wrote

Is it possible the ruins of an entire ancient civilization got subducted and are lost forever?

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sciencedthatshit t1_jb332xy wrote

If that civilization was on the ocean floor, sure.

The "what if geological processes erased a truely ancient civilization" question comes up frequently and the most rigorous treatment of this thought experiment is contained in a paper called The Silurian Hypothesis...check out the wikipedia article on it and the paper as well if you're interested in that sort of thing.

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[deleted] t1_jb373no wrote

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[deleted] t1_jb3fvbj wrote

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CrustalTrudger t1_jb4huld wrote

This presumes that the plate that "follows" is subductable or if it is subductable (i.e., it's oceanic) that the boundaries between the fully subducted plate and the following plate are such that allow for continued subudcution. None of those conditions are guaranteed and in fact with reference to the latter consideration, we very often see cessation of subduction when a mid-ocean ridge (i.e., the boundary between two oceanic portions of a plate) approaches or reaches a subduction zone.

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LordNoodles t1_jb57qjt wrote

What happens then? Like there’s the massive momentum, where does it go?

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CrustalTrudger t1_jb5hcc8 wrote

The force is driven by the negative buoyancy of the slab. If the slab detaches, there is no more driving force for the portion of the plate on the surface whereas the slab continues to sink. A simple analogy would be a weight clipped to the edge of a floating mat. If the mat rips, the portion attached to the weight will sink but the rest of the mat will just sit there (assuming it is buoyant). This is expanded on in much more detail in a top level answer I made within this thread to try to address the relative incompleteness of the specific top level comment that everyone is upvoting.

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[deleted] t1_jb39dd3 wrote

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NightOfTheLivingHam t1_jb49lsm wrote

I was about to say the farallon plate and there it is.

Its why nevada is a big stretch mark too.

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