Chemical composition and morphology of manganese nodules and crusts retrieved in the Pacific Ocean during GH80-5 campaign

Chemical analyses were made on one hundred and forty five powder samples taken from defined parts of manganese nodules retrieved during the GH80-5 campaign of the R/V Hakurei-Maru in the Pacific Ocean. The analyzed parts were prescribed according to external and internal morphology: samples from nodule tops, bottoms, outer layer, inner parts, and entire nodules were prepared. This description of analysed parts proved important in understanding the relationship between mineral and chemical compositions as compared with previous bulk analyses. More than one samples were selected from each station as representatives of the stations. Samples have been powdered and dried at 110° C. Seven metal elements have been determined by atomic absorption spectroscopy. Water content has been determined both for H2O+ by the Penfield method (gravimetric) and for H2O- as the drying loss at 100°C.