Electron probe microanalyses of ocean manganese nodules and a crust from the Groote Eylandt, Australia

Marine manganese nodules dredged from five locations in the central Pacific Ocean were studied for their mineral composition in todorokite. They were compared with pisolitic manganese ore from 'G' quarry on Groote Eylandt, off the north coast of Australia. The chemical composition of the todorokite rich areas in the samples was determined using Electron microprobe analysis (EPMA) using an ARL type EMX microprobe, with 52.5° take-off angle. Counting data were fully ZAF corrected ( ZAF model, see: https://link.springer.com/article/10.1007/BF01196142 ). All results listed are non-normalized, and totals are less than 100% because the phases are hydrated.