<p>It is claimed by some that the reason for gaps in chains of volcanoes generated by plate subduction is that some parts of the plate dive deep into the mantle and generate magma plumes, while other parts of the plate continue in an almost horizontal direction and therefore don't create magma plumes, hence the lack of volcanoes. Where one part of a plate continues almost horizontally while an adjacent section is driven down into the mantle, wouldn't that cause a violent fracture of the plate, and if not, why not? </p>

<p>Push a sheet of cardboard along a table top so that the leading edge of the cardboard overlaps the edge of the table, then grab a bit of cardboard and force it to descend. It will either carry the rest of the cardboard down with it, or it will break. I know that plates are not made of cardboard, but that's the best analogy I could think of to illustrate the principle. A similar fracture in an oceanic plate would surely be quite violent.</p>

CC BY-SA 4.0
2020-01-14T13:16:57.643Z
If you bother to read the second paper in my answer here (https://earthscience.stackexchange.com/a/18877), you'll have your answer in figure 1: the Nazca plate is divided into several segments moving at different velocities and separated by fracture zones. Some segments sink, other experience flat subduction.
Jean-Marie Prival
CC BY-SA 4.0
2020-01-14T17:26:32.597Z
Well, you have a reference given on Jan 4th. See below.
Michael Walsby
CC BY-SA 4.0
2020-01-14T18:00:38.207Z
Then please add it to your question. Click "edit", then third button from the left, paste the url, click "add link".
Jean-Marie Prival
<volcanology><plate-tectonics><earthquakes><magma-plumes>
How Can Adjacent Parts of an Oceanic Plate be Subducted in Different Directions?
Michael Walsby
# How Can Adjacent Parts of an Oceanic Plate be Subducted in Different Directions?

(Asked by: username_0 on 2020-01-14)

It is claimed by some that the reason for gaps in chains of volcanoes generated by plate subduction is that some parts of the plate dive deep into the mantle and generate magma plumes, while other parts of the plate continue in an almost horizontal direction and therefore don't create magma plumes, hence the lack of volcanoes. Where one part of a plate continues almost horizontally while an adjacent section is driven down into the mantle, wouldn't that cause a violent fracture of the plate, and if not, why not?

Push a sheet of cardboard along a table top so that the leading edge of the cardboard overlaps the edge of the table, then grab a bit of cardboard and force it to descend. It will either carry the rest of the cardboard down with it, or it will break. I know that plates are not made of cardboard, but that's the best analogy I could think of to illustrate the principle. A similar fracture in an oceanic plate would surely be quite violent.

**Tags:** volcanology, plate-tectonics, earthquakes, magma-plumes

> **Comments:**
> **username_1**: If you bother to read the second paper in my answer here (https://earthscience.stackexchange.com/a/18877), you'll have your answer in figure 1: the Nazca plate is divided into several segments moving at different velocities and separated by fracture zones. Some segments sink, other experience flat subduction.  
> **username_0**: Well, you have a reference given on Jan 4th. See below.  
> **username_1**: Then please add it to your question. Click "edit", then third button from the left, paste the url, click "add link".  

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