The yields of acid hydrocarbon belong to medium to low abundance compared with those of the subaerial basins and the East China Sea shelf basin, and show weak geochemical field features.

Massive projectiles striking much larger bodies create various kinds of craters, including multi-ring basins—the largest geologic features observed on planets and moons.

It seems possible that a sinking current of cooled mantle material on the upper side of the plate might be the cause of such deep basins.