The sediments on the bottom of the Pacific ocean are mainly oceanic in origin due to the lack of drainage from the continents

Off the eastern coast of the Pacific Ocean, the sediments on the ocean floors are almost entirely pelagic. This means that they are not derived from materials swept from the land, but rather from the remains of planktonic organisms that once inhabited the surface waters of the ocean. The immense size of the Pacific Ocean, and the fact that a very small land area actually drains into its waters, account for the almost exclusively oceanic origins of its sediments.