Ferromanganese Crusts of the Doldrums Fracture Zone, Central Atlantic: New Data on the Chemical Composition

摘要

New data on the morphology, chemical composition, and age of the ferromanganese crusts of the Doldrums Fracture Zone, Central Atlantic, collected during the 45th cruise of the R/V Akademik Nikolai Strakhov, are presented. According to studies of the chemical composition, the Doldrums crusts are characterized by high concentrations of Fe, Al, Si, and trace elements-Cd, Cr, Li, Hf, Nb, Sb, Sc, Th, W, and V. Most of the crusts have a two-layer structure: the upper layer shows an increased content of detritus and lower concentrations of Mn, Fe, Co, Ni, Cu, and REEs in comparison with the lower layer. The two-layered structure reflects the change in the conditions of crust formation.