中太平洋M海山富钴结壳稀土元素地球化学  

Geochemistry of Rare Earth Elements in Cobalt-Rich Crusts from the Mid-Pacific M Seamount

作　　者：崔迎春[1,2,3] 刘季花[2] 任向文[2] 石学法[2] 

机构地区：[1]中国科学院海洋研究所,山东青岛266071 [2]国家海洋局第一海洋研究所海洋沉积与环境地质国家海洋局重点实验室,山东青岛266061 [3]中国科学院研究生院,北京100039

出　　处：《中国稀土学报》2008年第6期760-768,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(40704029;40376016);国际科技合作项目(2006DFB21620);国家海洋局青年基金(2005304)

摘　　要：用ICP-AES和重量法测试了中太平洋M海山不同水深范围内（1300~3000 m）25个富钴结壳样品的稀土元素和常量元素。结果显示M海山富钴结壳为水成结壳,稀土元素总量平均为2084.69μg.g-1,LREE/HREE平均为4.84,具有正的Ce异常。ΣREE（不含Ce）随水深增加而增加,而Ce和LREE/HREE比值则以文石溶跃面为界（水深2000 m）呈现不同的变化,稀土元素这些变化除了与海洋背景颗粒的吸附清扫有关外,还与稀土元素在海水中的行为有关。富钴结壳Ce虽随水深变化,但与水深关系不明显,可能反映其通量恒定。富钴结壳中Ce基本全为Ce（Ⅳ）,表明氧化富集过程,这一过程受动力学因素控制。The REE and major elements of twenty-five cobalt-rich crusts obtained from different depths of Mid-Pacific M seamount were analyzed using ICP-AES and Gravimetric method. The results showed that they were hydrogenous crusts with average ∑ REE content of 2084.69 μg·g^-1 and the LREE/HREE ratio of 4.84. The shale-normalized REE patterns displayed the positive Ce anomalies. The total content of strictly trivalent REEs increased with water-depth. The Ce content and LREE/HREE ratios in Fe-Mn crusts above 2000 m were lower than those below 2000 m. The change of REE with water depth could be elucidated with two processes： adsorptive scavenging by setting matters and the behaviors of REE in seawater. However, it was clear that there was not obvious correlation between-Ce abundance and water-depth, which reflected the constant Ce flux. The Ce in crusts existed mainly as Ce（ Ⅳ ）, implying that the oxidative enriching process was controlled by kinetic factors.

关 键 词：稀土元素 富钴结壳 M海山 中太平洋 

分 类 号：P618.7[天文地球—矿床学] P744.3[天文地球—地质学]