Oceanic crust transition elements

Iron is the most abundant transition element in the Earth s crust and, in general, in all life forms. An outline of the distribution of iron in the Earth s crust is shown in Table 1.2. As can be seen, approximately one-third of the Earth s mass is estimated to be iron. Of course, only the Earth s crust is relevant for life forms, but even there it is the most abundant transition element. Its concentration is relatively high in most crustal rocks (lowest in limestone, which is more or less pure calcium carbonate). In the oceans, which constitute 70 percent of the Earth s surface, the concentration of iron is low but increases with depth, since this iron exists as suspended particulate matter rather than as a soluble species. Iron is a limiting factor in plankton growth, and the rich... 

Manganese is the twelfth most abundant transition element (1,060 parts per million of Earth s crust) with twenty-three known isotopes. Large nodules of manganese ore have been discovered on the ocean floor. The pure metal can be obtained by reduction of the oxide with sodium or by electrolysis. 

This highly corrosive fluid is now capable of leaching elements such as Li, K, Rb, Ca, Ba, the transition metals Fe, Mn, Cu, Zn, together with Au, Ag and some Si from the oceanic crust (Mottl 1983 Table 13.2). Metals and S are leached mainly from immiscible sulfide droplets trapped in the crystallized magma (e.g., Keays 1987 Shanks... 

Table 19.1 shows the distribution of elements in the earth s crust, oceans, and atmosphere. The major element is, of course, oxygen, which is found in the atmosphere as O2, in the oceans in H2O, and in the earth s crust primarily in silicate and carbonate minerals. The second most abundant element, silicon, is found throughout the earth s crust in the silica and silicate minerals that form the basis of most sand, rocks, and soil. The most abundant metals, aluminum and iron, are found in ores in which they are combined with nonmetals, most commonly oxygen. One notable fact revealed by Table 19.1 is the small incidence of most transition metals. Since many of these relatively rare elements are assuming... 

---