Bulk chemical composition of manganese deposits fom the Pacific and Indian oceans

Manganese nodules retrieved by early cruises of the R/V Hakuho Maru in the Pacific Ocean and the R/V Umikata Maru in the Indian Ocean have been chemically analysed. Samples were dried at 300°C in order to remove volatile water components and were then treated with 3N-hydrochloric acid and a few drops of 30% hydrogen peroxide. The acid soluble part was then submitted to atomic absorption spectrophotometry to determine the composition of Mn, Fe, Ni, Cu and Co.