You want to know where the sediments came from? They were washed off the land and churned up from the ocean..
Wouldn't that moving sediment up from the depths of the ocean basins onto the continental plates require velocities so high that the sediment would just be washed back off the continents?
We would see, in the ocean basins, thick layers of sand downstream of the continents and only thin, recent layers on the upstream side. To my knowledge we don't see that.