Answer:
Anywhere along the mid-atlantic ridge
Step-by-step explanation:
It goes through a bunch of history, such as the Continental Drift Theory from Alfred Wegener to Harry Hess proving it. So, in WW2, Harry Hess was in the navy (he was a geographer/geologist who noticed while using sonar, that the waves were bouncing back uneven when they launched sonar, which proved the ocean floor was not flat like how they used to beleive it was.
Anyways, they discovered the mid-atlantic ridge, (you can see it on maps! Go to a search engine's maps and look at the atlantic ocean and you can see this weird ridges along with these (not latitude or longitude) lines.
The mantle in the Earth's layers is moving the plates (continental and oceanic plates to be exact) from convection currents, and there is very deep trenches in the Earth, such as the Mariana Trench. The mantle pushes magma through some holes, and it rises and cools in the ocean, which is then pushed aside by more solidifiying magma in a process called seafloor spreading. Magma is called lava when it comes out of the place where it comes from, so the lava cools into rock which is called basalt too.
Hope this helps anyone in the future!
I don't mean to be a boomer by necroposting
dont roast me plz