中文摘要:文章以大洋海山铁锰结壳与南极底层流（AABW）之间关系的角度，从铁锰结壳的结构构造、矿物组合，特别是结壳新壳层的Ce异常和Ce/La比值的区域分布来探讨AABW的活动在铁锰结壳中留下的证据。主要对中太平洋和西北太平洋5座海山的17个铁锰结壳新壳层样品进行了结构构造分析和REE含量测定。结果表明，铁锰结壳的REE含量很高，平均为1 716.66×10-6，且轻稀土元素明显富集，LREE/HREE平均值为4.82，除MID06样品具微弱的Ce负异常外，其他铁锰结壳样品均具明显的Ce正异常。为了对比研究AABW的影响，除铁锰结壳外，还引用了不同区域的多金属结核的稀土元素平均值资料按不同区域进行了对比研究，结果发现，AABW活动区和非活动区的δCe值和Ce/La比值有显著差异。一般来说，沿AABW流路，从南向北，δCe值和Ce/La比值有逐渐减小的趋势，但在局部地区，如地形复杂的海山区，AABW的强度会发生变化，其Ce正异常和Ce/La比值可能会局部增大。本项研究成果将有助于全面认识大洋成矿作用与海洋环境变迁的内在联系。
Abstract:According to the relationship between ferromanganese crusts in big ocean seamount area and the AABW, the structure, mineral components, and especially Ce anomalies and Ce/La ratios of the ferromanganese crusts, this paper summarized the characteristics of Antarctic Bottom Water (AABW) which is existent in ferromanganese crusts. 17 ferromanganese crust samples in Central Pacific area and West Pacific area were analyzed structurally and the REE contents were determined with the ICP_MS method. It is shown that the REE contents in the ferromanganese crusts are relatively high, with an average of 1 716.66×10-6, and LREE contents are especially prominent, with the LREE/HREE ratio being 4.82. With the exception of the MID06 sample which has weak Ce negative anomaly, all ferromanganese crust samples show obvious Ce positive anomalies. In order to make a comparative study of the effects of the AABW, the authors investigated average REE values of polymetallic nodules from different regions besides data of ferromanganese crusts and found that Ce/La ratios of the AABW active area are remarkably different from those of the inactive area. In general, δCe values and Ce/La ratios seem to decrease gradually from south to north. However, in some local areas, such as the topographically complex terrain, the intensity of AABW may change, and its Ce positive anomalies and Ce/La ratios will increase. The result of this study helps to understand the internal relation between the big ocean mineralization and the marine environment variation.
keywords:geochemistry ferromanganese crusts Antarctic bottom water rare earth elements seamount central Pacific area
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基金项目:国家“十五”大洋专项基金（DY105_01_04_3）和国家自然科学基金（40206010）
引用文本：
韩 杰，武光海，叶 瑛, 邬黛黛.2006.铁锰结壳中底层洋流活动的地球化学研究[J].矿床地质,25(5):620~628.2006.Geochemical record of bottom water in ferromanganese crusts[J].Mineral Deposits25(5):620~628
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