Geochemistry, description and mineralogy of sediments at DSDP Holes 92-597B and 92-597C

B, Li, and other trace elements were analyzed in samples from 12 celadonite and smectite-rich veins from oxidative and non-oxidative alteration zones in basalts from Holes 597B and 597C. The oxidative alteration zones are characterized by celadonite and Fe-oxyhydroxide and conspicuously high K, Rb, and B concentrations. In contrast, the non-oxidative alteration zones are characterized by Mg-rich smectite (saponite), talc, and calcite and high Li concentrations. Neither B nor Li reaches high concentrations in high-Al high-Ti veins that appear to have formed by replacement of basalt. B, Li, and Rb enrichments in vein assemblages of low-temperature origin reflect an important removal mechanism from seawater for these species.
The alteration zones characterized by Mg-smectite and talc are strikingly enriched in Ni. There is a correlation between the Ni-enriched smectite and the presence of olivine in the host basalt; the correlation indicates that olivine alteration may be the source of the Ni. Other transition elements, including Cr, Mn, Co, Cu, and Zn, are often found in significant concentrations in the celadonite and high-Mg smectite veins, but their enrichments are neither as large nor as consistent as the enrichment of Ni in the Mg-smectite veins.
Two high-Al, high-Ti vein assemblages of smectite and noncrystalline phases have transition element abundances similar to those of the host basalts but are relatively depleted in Cu and Cr. The material in these veins may have formed by replacement with concomitant release of Cu and Cr to circulating aqueous fluids.