“…This is primarily inferred through the comparison of MnO/FeO values which are virtually unaffected by mixed analyses with the Si-rich host material on top of which Mn-Fe mineralization developed. The MnO/FeO in the studied micronodules is on average 4 ± 2 ( Table 1) which fits the range shown by Mn-nodules (MnO/FeO =~3-6, Table 1, analyses 70, 72, 96, 97, 50p, 51p, 52p) recovered from the ocean floor [77]. Moreover, the exceedingly high MnO/FeO reported in the dendritic outgrowths (Figure 2e), spanning from~14 to 23 (Table 1, analyses 80,81,86), is comparable with the nodules of analogue morphology documented offshore Peru (MnO/FeO~15.6 to 21) [75,76].…”