(Table, page 351-359) Chemical composition of manganese nodules and crusts from the Pacific and Indian Ocean

Chemical and mineralogical analyses of manganese nodules from a large number of widely spaced localities in the Pacific and Indian Oceans have shown that their mineralogy and chemical composition varies both areally and with depth of formation. This is considered to result from a number of factors, important among which are: (a) their proximity to continental or volcanic sources of elements; (b) the chemical environment of deposition, including the degree of oxygenation; and (c) local factors such as the upward migration of reduced manganese in sediments from certain areas. Sub-surface nodules appear to share the chemical characteristics of their surface counterparts, especially those from volcanic areas where sub-surface sources of elements are probably important.

对太平洋与印度洋内大量分布间距较大的采样位点采集的锰结核（manganese nodules）开展化学与矿物学分析后发现，其矿物组成与化学组分在空间分布及形成深度两个维度上均存在显著差异。该现象被认为由多重因素共同作用所致，其中关键影响因素包括：(a) 采样位点与大陆或火山元素源的空间邻近度；(b) 沉积化学环境，涵盖水体氧化程度；(c) 局部环境因素，例如特定区域沉积物中还原态锰的向上迁移作用。次表层锰结核（sub-surface nodules）的化学特征与表层锰结核整体相似，尤其在元素次表层来源可能发挥主导作用的火山区域，这种相似性表现得更为突出。