Geochemical and mineralogical property of ferromanganese oxides precipitates over the rock outcrops; implication to the diversity of ferromanganese crusts

Abstract

The rock outcrops of the sea mount and escarpments are usually covered with black iron-manganese oxide patina or thick stiff layers of the oxide deposits. The deposits are of significant variety of chemistry, mineralogy and microstructures. The diversities in time and place are important keys to understand the paleographic geological and oceanographic environments as well as to evaluate the economic potential of the ferromanganese crusts in the world oceans. We collected ferromanganese oxide patina, undisturbed surfaces of hydrogenetic ferromanganese crusts, and precipitates of long-term exposure experiments on seabeds, and analyzed with chemistry, microstructure, and mineralogy, and attempted to correlate the variability with modern oceanography and sea floor geology.