I'm working through Artifaxian's (https://www.youtube.com/watch?v=AzD_WVsEIRM) series on using gPlates to make tectonic history. I've run into the place where I have two subduction ridges about to meet. The bottom continent is moving up, the one at the top is moving down. Which one is likey to subduct?

I can imagine that the unified front of the bottom subduction could make it easier for it to take under the top subduction zone. Likewise I could imagine that the sharp point could pierce the bottom one.

The ocean crust segments are the same age.

Thanks for any thoughts and ideas you share!

enter image description here


1 Answer 1


If two continental plates meet, neither generally subduct -- you just get a big collision, in the way the Alps and the Himalayas are formed. That's because continental plates are relatively light, and neither wants to disappear into the mantle.

If a continental and an oceanic plate meet, the oceanic plate (being denser) generally loses the battle and subducts. If two oceanic plates meet, it's a toss-up.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.