DISTRIBUTION OF MN, FE, NI, CO, AND CU IN YOUNG SEDIMENTS ON THE PALINURO SEAMOUNT IN THE SOUTHEAST TYRRHENIAN SEA (MEDITERRANEAN)

An extensive offshore exploration campaign, aiming at identifying and evaluating the ferromanganese-bearing encrustations and micronodules discovered previously on the top sediment layers of the seamounrt, provided the means for constructing the geochemical maps of Mn, Fe, Ni, Co, Cu and of interpreting a complex metals history that in addition to ferromanganese mineralization, resulted in metal-bearing massive sulfides interpreted to be the outcome of ongoing hydrothermal activity. The data have shown meaningful associations: the first (Fe-Cu) is interpreted as being linked with the sulfides,; the second (Mn-Ni-Co), with ferromanganese bearing encrustations and micronodules. In relation to the area where sulfides were discovered, the zoning of Mn and Fe supports the idea that encrustations and micronodules are also primarily of hydrothermal origin. This interpretation is supported by using a discriminant plot. The presence of traces of ferromanganese mineralizations associated with low redox facies in depth is viewed as being caused by remobilization of previously deposited Mn mineral phases, thus posing the question that diagenetic processes may also have played a significant role in the deposition of the encrustations and micronodules.