Erosion, Sedimentation and Sedimentary Origin of Clays

Of all the various types of sediment, fine-grained sediments with a high proportion of clay minerals are by far the most abundant. In the marine environment, terrigenous (land-derived) muds cover about 60% of the continental shelves, and almost 40% of the deep ocean basins, amounting in total to about a third of the Earth’s surface (Fig. 4.1). Similarly, although proportionally much smaller in area, continental aquatic environments are often dominated by fine-grained sediments, and these environments include many of the rivers, lakes, deltas and estuaries used extensively by man.