Analysis of spherules from Pacific Ocean sediments

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.