The distribution of Pb, Ag, Sn, Tl, and Zn in sediments on active oceanic ridges

Abstract

Ninety-five sediment samples, taken from traverses across active oceanic ridges, were analyzed by emission spectrography for Pb, Ag, Sn, Tl, and Zn. The concentration patterns produced from these analyses indicate that processes associated with active oceanic ridges partially affect the distribution of Pb, Tl, and Zn, while the distribution of Ag is affected only in the Pacific and western Indian Ocean, and Sn distribution is not related to any active ridge process. The covariation between distance from a ridge and concentration indicates that the ridge effects are not more than 10%. Average concentrations (weighted by sedimentation rates) were determined for Pb, Ag, Sn, Tl, and Zn in parts of the Pacific, the Atlantic, and the Indian Ocean. On the basis of the high elemental concentrations of Pb, Tl, and Zn in the Pacific, the intermediate concentrations in the Indian Ocean, and the low concentrations in the Atlantic, it is inferred that the East Pacific-Antarctic Ridge system is the most active, the north Mid-Atlantic Ridge is the least active, and the Indian Ocean Ridge system is of intermediate activity; all of which seems to be in accord with presently available geophysical data for the same regions.