西太平洋海山区深海软泥中稀土元素富集的地球化学特征  

Enrichment and Geochemical Characteristics of Rare Earth Elements in Deep-Sea Mud from Seamount Area of Western Pacific

作　　者：张霄宇[1] 邓涵[1] 张富元[2] 章伟艳[2] 杜泳[1] 江彬彬[1] 

机构地区：[1]浙江大学地球科学系,浙江杭州310027 [2]国家海洋局第二海洋研究所海底科学重点实验室,浙江杭州310012

出　　处：《中国稀土学报》2013年第6期729-737,共9页Journal of the Chinese Society of Rare Earths

基　　金：浙江大学海洋学科交叉研究引导基金项目(2012HY006A);国家自然科学基金(40706057);大洋专项基金(DY125-14-R-01);973项目(2012CB417305)资助

摘　　要：对西太平洋海山区和东太平洋CC区18个站位40个沉积物样品进行了元素测定,以探讨西太平洋海山区含沸石深海粘土中稀土元素富集的地球化学特征和可能的富集机制。西太平洋海山区沉积物类型复杂,含沸石型深海粘土中富含各类微量元素,尤其以稀土元素富集程度最大,接近或高于中国南方离子吸附型稀土矿床,含沸石型深海粘土主要分布在马绍尔和莱恩群岛,∑REE最高达1018.84μg·g-1,其中∑LREE为781.00μg·g-1,∑HREE为237.84μg·g-1。平缓的北美页岩归一化模式、显著的δCe负异常、以及轻中重稀土分馏特征表明热液铁锰水合物以及早期成岩的含磷矿物混入是造成含沸石深海粘土中稀土元素富集的可能机制。含沸石型深海沉积物中REE的具体富集机制还需要做进一步的研究。40 sediment samples were collected in 18 stations from seamounts areas in Western Pacific and from CC zone in Central Pacific. Based on the meas- urements of main elements and minor elements including Rare Earth Elements （REEs）, the geochemical characteristics of REE enrichment in zeolitic clay were analyzed. The zeolitic clay was found to be distributed mainly at Marshall Seamounts and Line Islands, marked by high content of metal elements and especially of REEs. The observed highest content of REE in zeolitic clay was 1018.84 μg·g^-1, with the highest ∑LREE of 781.00 μg·g^-1, and the highest ∑HREE of 237.84 μg·g^-1, which were comparable to or even greater than REEs content from the southern China ion-absorption-type deposits. The normalizd REEs with North American Shale Composite （NASC） in zeolitic clay displayed gentle slope, distinct negative Ce anomaly and fractionation of HREE and LREE, which suggested that combined effect of hydrothermally Fe- Mn oxyhydroxides and mixture of phosphatic mineral formed during early diagenesis are possible mechanism of REEs enrichment in zeolitic clay, but needs further study.

关 键 词：西太平洋海山区 含沸石深海粘土 富集特征 稀土 

分 类 号：P736.21[天文地球—海洋地质]