Chemical composition of manganese micronodules from expedition VA-05/1 in the Pacific Ocean

DOI

A radioisotope energy-dispersive X-ray (EDX) system has been used on board the German research vessel "Valdivia" during an exploration expedition in the northern equatorial Pacific in 1973. The instrumentation used consisted of an X-ray detection system incorporating a 30 mm2 effective-area Si (Li) detector with a measured energy resolution of 195 eV for Mn K alpha X-rays, standard nuclear electronics, a 1024-channel analyser and a data read-out unit. The X-ray spectra in the manganese-nodule samples were excited by a 30-mCi 238Pu source. The six elements Mn, Fe, Co, Ni, Cu and Zn were analysed on board. Precision values for the analyses were less than 3% for Mn, Fe, Ni, Cu and Zn and about 5% for Co. A total amount of 350 analyses was carried out during a one-month cruise. Average contents of 190 analysed whole manganese-nodule samples from all the sampling sites of the covered area were 23.3% Mn, 6.7% Fe, 0.23% Co, 1.16% Ni, 0.94% Cu and 0.10% Zn. The average content of the base metals expressed as the sum of the Co, Ni, Cu and Zn contents was 2.48%. A linear relationship between Mn and Ni in all analysed samples, including whole manganese-nodule samples, zones of manganese nodules and manganese crusts, was observed. The Mn/Ni ratio calculated by regression analysis was 23.0. Zonal variations of the chemical contents of the six elements in the manganese nodules were found. A size classification of the manganese nodules has been suggested. Geochemical correlations of Cu and Ni versus Mn/Fe in the investigated samples are given.

From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis...) not present in the NOAA-MMS database.

Supplement to: Friedrich, Günther; Kunzendorf, Helmar; Plüger, W L (1974): Ship-borne geochemical investigations of deep-sea manganese-nodule deposits in the Pacific using a radioisotope energy-dispersive X-ray system. Journal of Geochemical Exploration, 3(4), 303-317

Identifier
DOI https://doi.org/10.1594/PANGAEA.865317
Related Identifier https://doi.org/10.1016/0375-6742(74)90001-6
Related Identifier https://doi.org/10.7289/V52Z13FT
Related Identifier https://doi.org/10.7289/V53X84KN
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.865317
Provenance
Creator Friedrich, Günther; Kunzendorf, Helmar; Plüger, W L
Publisher PANGAEA
Publication Year 1974
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 3 datasets
Discipline Earth System Research
Spatial Coverage (-152.500W, 7.950S, -146.300E, 11.100N)