CLASSIFICATION OF DEEP-SEA, FINE-GRAINED SEDIMENTS

Most deep-sea sediments contain one or more biogenic components and one dominant nonbiogenic component, usually clay or silty clay. We present a desefiptive classification scheme in which deep-sea, fine-grained sediments are placed within a three-component system ofcalcareous-biogenic, siliceous-biogenic, and nonbiogenic components. In a three-step procedure the user assesses whether the dominant component is biogenic or nonbiogenic, whether the dominant biogenic component is siliceous or calcareous, and what the relative abundances of the biogenic components are within limits of 10, 25, and 50%. The terminology proposed is that commonly used by many sedimentologists, with some refinements and greater precision in the use of terms. © 1985,The Societyof EconomicPaleontologistsand Mineralogists.