Metallic spherules from Central Pacific Ocean sediments (“Valdivia” expedition VA-05/1, 1973) were studied by means of microscopy and by electron microprobe analysis. The data suggest that most of the spherules are of meteoritic origin, i.e. ablation drops from meteorites as suggested in former studies on spherules from marine environment by Schmidt and Keil (1966), Finkelmann (1970, 1972) and others. The metallic spherules contain up to about 60% Ni, 37% Fe and 3% Co. Unusually high contents of Cr (up to 12%) were noted in some spherules. Some specimen being coated with Fe oxide could be mistaken for manganese micronodules always abundant in the sediments of the Central Pacific Ocean.
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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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, G; Schmitz-Wiechowski, A (1976): Mikroskopische und mikroanalytische Untersuchungen an metallischen Kügelchen aus Tiefseesedimenten des Zentralen Pazifik. Marine Geology, 20(3), 239-250