(Table 1, Page 402) Chemical and radiochemical data for nodule SO11-278DK from the Peru Basin, Southeast PAcific Ocean

Recent studies on marine ferromanganese nodules have suggested a relationship between their growth rate and their chemical composition. The suggestion is based on the hypothesis that the metals in nodules have two sources of supply: bottom seawater (hydrogenous) and sediment pore water (diagenetic). The diagenetic source calls for upward diffusion of Mn mobilized in a deeper, low Eh zone of the sediment column and its subsequent precipitation in an oxidized surface zone. Addition of the remobilized Mn to surface nodules would augment their accretion rate. It would also render the oxide layers to contain higher Mn/Fe ratios than layers resulting from hydrogenous precipitation. We report here a radiometrically determined accretion rate of 168±24 mm/Myr for a deep-sea manganese nodule from the Peru Basin in the Pacific. This rate is about two orders of magnitude higher than that frequently found in nodules of deep-sea origin, and emphasizes the importance of sediment diagenetic processes on the growth of manganese concretions.针对海洋铁锰结核 (marine ferromanganese nodules) 的近期研究已揭示其生长速率与化学成分之间存在关联。该结论基于如下假说：结核中的金属存在两种供给来源：底层海水 (hydrogenous，水成成因) 与沉积物孔隙水 (diagenetic，成岩成因)。成岩成因来源要求沉积物柱深部低氧化还原电位 (Eh) 带中活化的锰向上扩散，并随后在氧化表层带中发生沉积。将再活化的锰添加至表层结核中，不仅会提升其增生速率，还会使氧化层的锰铁比高于水成沉积形成的氧化层。本文报道了采自太平洋秘鲁海盆的一处深海锰结核的放射测年增生速率：168±24 毫米/百万年。该速率约为常见深海成因结核增生速率的两个数量级，凸显了沉积物成岩作用对锰结核生长的重要性。