(Table 1, page 262) Chemical data on the major- (wt. %) and minor (ppm) element contents of the Tyrrhenian Sea crusts (T/76 series)

Dark crusts and concretions on volcanic and calcareous rocks dredged from seamounts west of the Aeolian Islands, southern Tyrrhenian Sea, consists mainly of amorphous Fe-Mn hydroxides, with some goethite, todorokite, birnessite and clastic minerals. Chemically they consist of predominant Fe (up to 45%) and Mn (up to 12%), with significant amounts of Zn, Ni, Co and Cu. That the REE distribution patterns are similar to those of shallow Pacific derivation - from hydrothermal waters cognate or cycled through volcanic rocks of intermediate composition - is tentatively suggested.