Figure 6. Distribution of radiolarian oozes in the World Ocean. Upon death Polycystine shells settle to the sea floor. While these shells are not immune to dissolution, in many areas input from the water column exceeds the rate of dissolution, so that skeletons pile up on the bottom forming layers tens to hundreds of meters thick. These sediments where radiolarian shells are a major component are known as radiolarian oozes. Modified from Lisitzin, A.P., 1974. Osadkoobrazovanie v okeanakh. Nauka, Moskva, pp. 1-438.