ABSTRACT: New Data on Trace Elements in Pacific Manganese Nodule Deposits
Ronald K. Sorem
New analyses of 94 representative manganese nodules from 36 sites in the NE Pacific Ocean reveal geographic variations in concentrations of 36 chemical elements. ICP analyses were run on nodules from five regions: (l) the entire NE Pacific, (2) locations north of the Clarion Fracture Zone, (3) DOMES Site A area, (4) DOMES Site C area, and (5) the entire C-C^prime region.
Compared to mean concentrations in Region 1, mean values for Region 2 are higher for Fe and the minor elements Ce, Gr, Dy, Gd, La, Nb, Nd, P, Pr, Sc, Sm, Ti, Y, and Zr, and lower for the major metals Mn, Cu, Ni, Co, and Zn. The Region 3 analyses are higher for Mn, Fe, Cu, and Ni, as well as for Dy, Gd, La, Mo, Nb, Nd, P, Pr, S, Sc, Sm, Sr, Ti, V, Y, Yb, and Zr. Co and Zn are about the same as for Region 1. Mean values for Region 4 are higher for Mn, Cu, Ni, Co, Zn, and the minor elements Cd, Li, Mo, V, and W, and lower for Fe.
Correlation coefficients support the well-known correlation of Mn with Cu, Ni, and Zn content and other correlations less well-known. Correlations of minor elements with (Ni+Cu) content were calculated because concentration of (Cu+Ni) may well be the major factor in selection of nodule mining sites in the future. When mining of nodules takes place, recoverable amounts of Cd, Li, Mo, and V may be found in the concentrates, along with traces of perhaps a dozen other elements. Production of some minor elements may be profitable.
Further research on the role of minor elements in nodule origin, growth, and distribution is needed to explain the partitioning reported.
AAPG Search and Discovery Article #90097©1990 Fifth Circum-Pacific Energy and Mineral Resources Conference, Honolulu, Hawaii, July 29-August 3, 1990