Experiments on the deposition of iron with special reference to the Clinton iron ore deposits

Abstract

Laboratory experiments simulating conditions of formation of the Clinton iron ores show that significant quantities of ferrous iron can be carried in solution in aerated river waters of pH 7 or lower. If such waters enter a marine environment with solid calcium carbonate in equilibrium with the sea water, the iron is essentially completely precipitated as ferric oxide, both in the water and as direct replacement of the calcium carbonate. Quantitative data are presented relating both ferrous and ferric iron concentration to the pH and reduction-oxidation potential of the environment. Suggestions are made as to the major controls of iron deposition as oxide, silicate, or carbonate.