Iridium in natural waters
- California Institute of Technology, Pasadena, CA (United States); and others
Iridium, commonly used as a tracer of extraterrestrial material, was measured in rivers, oceans, and an estuarine environment. The concentration of iridium in the oceans ranges from 3.0 ({+-}1.3) x 10{sup 8} to 5.7 ({+-}0.8) x 10{sup 8} atoms per kilogram. Rivers contain from 17.4 ({+-}0.9) x 10{sup 8} to 92.9 ({+-}2.2) x 10{sup 8} atoms per kilogram and supply more dissolved iridium to the oceans than do extraterrestrial sources. In the Baltic Sea, {approximately}75% of riverine iridium is removed from solution. Iron-manganese oxyhydroxides scavenge iridium under oxidizing conditions, but anoxic environments are not a major sink for iridium. The ocean residence time of iridium is between 2 x 10{sup 3} and 2 x 10{sup 4} years. 32 refs., 3 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG03-88ER13851
- OSTI ID:
- 433224
- Journal Information:
- Science, Vol. 273, Issue 5281; Other Information: PBD: 13 Sep 1996
- Country of Publication:
- United States
- Language:
- English
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