Chemical analysis of manganese nodules from the Cape Leeuwin field, southeast Indian Ocean

Manganese nodules from 36 stations in the Cape Leeuwin field were analyzed for Mn, Fe, Ni, Cu and Co and the results were combined with earlier work to demonstrate quantitative and geographic variations. Nodules in this field are moderately enriched in Ni, moderately depleted in Cu, and contain intermediate values of Co. The sum of Ni + Cu vs. Mn/Fe plots along a hyperbolic regression line derived from nodules of the southeastern Pacific, suggesting that this relationship has general applicability. Regional variations in nodule grade (Ni + Cu + Co) assist in defining pathways of Antarctic Bottom Water between the Southeast Indian Ridge and the Wharton basin.对卢因角海区（Cape Leeuwin field）36个站位的锰结核（Manganese nodules）测定了其中锰（Mn）、铁（Fe）、镍（Ni）、铜（Cu）及钴（Co）的含量，随后将本次分析结果与既往研究数据相结合，以阐明其含量的定量变化与地理分布特征。该海区的锰结核镍含量呈中等富集状态，铜含量相对贫化，钴含量则处于中等水平。镍与铜的含量总和（Ni+Cu）与锰铁比值（Mn/Fe）的散点分布沿一条由东南太平洋锰结核推导得到的双曲线回归曲线分布，这表明该含量关系具备普遍适用性。锰结核品位（Ni+Cu+Co）的区域差异，有助于厘清南极底层水（Antarctic Bottom Water）在东南印度洋海岭（Southeast Indian Ridge）与沃顿海盆（Wharton basin）之间的运移路径。