mark all true statements The process of subduction pulls material down into the mantle to be recycled at a mid ocean ridge. The process of sea floor spreading adds new crust to the Ocean floor on both sides of the deep ocean trench. The process of subduction pulls material down into the mantle to be recycled at a deep ocean trench. Sea floor spreading creates crust. as subduction recycles it. The process of sea floor spreading adds new crust to the Ocean floor in both sides of the mid ocean ridge.