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.对597B孔和597C孔玄武岩中氧化蚀变带与非氧化蚀变带的12条富绿鳞石(celadonite)和蒙脱石(smectite)脉体样品，开展了硼(B)、锂(Li)及其他微量元素的分析测试。氧化蚀变带以绿鳞石、铁羟基氧化物(Fe-oxyhydroxide)为特征，且钾(K)、铷(Rb)、硼(B)浓度显著偏高。与之相反，非氧化蚀变带以富镁蒙脱石（皂石saponite）、滑石(talc)和方解石(calcite)为特征，且锂(Li)浓度较高。在被认为由玄武岩交代形成的高铝高钛脉体中，硼与锂均未出现高浓度富集。低温成因脉体组合中的硼、锂、铷富集现象，反映了这类元素从海水中被移除的一种重要机制。 以镁蒙脱石和滑石为特征的蚀变带，镍(Ni)富集现象极为显著。富镍蒙脱石与寄主玄武岩中的橄榄石(olivine)产出存在相关性，这一关联表明橄榄石蚀变可能是镍的来源。其他过渡金属元素(transition elements)包括铬(Cr)、锰(Mn)、钴(Co)、铜(Cu)和锌(Zn)，常以显著浓度赋存于绿鳞石和高镁蒙脱石脉体中，但其富集幅度既不及镁蒙脱石脉体中的镍富集，富集持续性也不如后者。 两组由蒙脱石与非晶质相组成的高铝高钛脉体组合，其过渡金属元素丰度与寄主玄武岩相近，但铜、铬相对亏损。此类脉体的形成可能源于交代作用，且伴随铜、铬向循环流体中的释放过程。