[MZZ41-P06] Identification of oxide layer structures of ferromanganese nodules in the Minamitorishima EEZ using X-ray CT
Keywords:ferromanganese nodules, X-ray CT analysis, Minamitorishima EEZ
In this study, we conducted X-ray CT analysis of the nodules from the Minamitorishima EEZ to nondestructively identify the internal structures of the nodules. As a result of the analysis, it was defined that the oxide layers of the nodules can be classified into 5 layers on the basis of the difference in X-ray absorption rate. We also found that the X-ray absorption rate corresponds to both the growth texture and chemical composition of the oxide layers. Moreover, several peaks were observed in the histograms of the total oxide layer thickness, and these peaks corresponded to number of oxide layers. This suggests that formations of ferromanganese nodules occur intensively during certain periods when each oxide layer starts growing.
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