in earths crust, what type of rock is found under the oceans?

Answer 1

I believe that would be sedimentary rock, due to the fact that heavy particles descending to the ocean floor settle on top of each other until the sheer weight begins to compact and compress, over centuries and eons, until it becomes sedimentary rock.

Answer 2

the type of rocks found on the bottom of the ocean are generally just like the ones found on land because the bottom of the ocean is still part of the earths crust

Answer 3

Indeed, over time, sedimentary rock is formed under oceans, except along the mid ocean ridge, there you find igneous.