Chemical composition of ferromanganese nodules from the Pacific Ocean obtained by solution in HCl and H2SO4

Mn nodules from the Pacific ocean were retrieved during expeditions of the R/V Vytiaz and analysed for their chemical composition after separation of soluble (authigenic) part from insoluble (detrital) part using a 1 M Hydroxylamine Hydrochloride solution and a 2% HCl solution after 5 minutes boiling.