Geochemistry of Marine Sediments



The uplift of rocks above sea level on the Earth's surface over geologic time produces material that can be altered into soils and sediments by weathering processes. Over time, a fraction of sediments are sequestered in ocean basins, with most of it stored in the coastal margin. Sediments produced from weathering of igneous, metamorphic, and sedimentary rocks are transported primarily to the oceans through the world's river systems. The storage of organic matter in marine sediments is largely dependent upon the amount of early diagenesis (processes that alter the structure, texture, and mineralogy of a sediment, turning it progressively into solid hard rock; early diagenesis occurs immediately after deposition or burial of the sediment) that occurs in the upper sediments, which is controlled largely by the “quality” of organic detrital inputs and redox conditions of the sedimentary environment.