Chemical constituents of selected ferromanganese crust samples from the Hawaiian Archipelago

Bottom dredging during the KK84 campign of the R/V Kana Kenoki recovered numerous ferromanganese crusts on a large variety of substrate (basalt, volcanics, limsetone and phosphorite). These deposits were sampled using hard substrate coring device. The retrieved part was air-dried at 110°C and reduced to powder. One split was dissolved by acid-pressure digestion with concentrated, ultrapure HCI-HNO3-HF and the dissolved residue was analysed for major and selected minor constituents by atomic absorption spectrophotometry (AAS) using a Perkin-Elmer Model 603 doublebeam spectrophotometer. Loss-on-ignition (LOI) determinations were also carried on the duplicate splits for 30 min at 1000°C in a muffle furnace.