ABSTRACT
The formation of ocean basins was closely coupled to the development of the global plate tectonics theory that revolutionized the field of marine geology during the 1960s. Biogenic sediment is composed of shells and skeletal remains of marine organisms, particularly plankton. Both larger plastics and microplastics can be detrimental to marine life and marine food webs. Marine planktonic organisms produce nearly all skeletal remains deposited on the deep ocean floor. Submarine volcanism produces far less marine sediment than subaerial eruptions. Clays exist in low-energy environments throughout the marine realm, settling out of suspension to the seafloor. The gradient of the seafloor increases significantly when proceeding from the continental shelf to the continental slope. Continental slopes and rises generally have the thickest sediments within continental margin provinces. Continental slopes and rises are most extensively developed on Atlantic-type margins, where tectonically quiescent conditions enable thick terrigenous sediment masses to accumulate.
