麦哲伦海山群富钴结壳铈富集的控制因素  

Controlling Factors on Enrichment of Cerium in Co-Rich Fe-Mn Crusts from Magellan Seamount Cluster

作　　者：任向文[1,2] 石学法[1] 朱爱美[1] 刘季花[1] 方习生[1] 

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

出　　处：《中国稀土学报》2010年第4期489-494,共6页Journal of the Chinese Society of Rare Earths

基　　金：科技部国际科技合作重大项目(2006DFB21620);国家自然科学基金项目(40806027);国际海底区域研究开发“十一五”课题(DYXM-115-01-2-1,DYXM-115-01-2-7);国家海洋局第一海洋研究所基本科研业务费专项资金项目(2008T03,GY02-2009G23);“泰山学者”建设工程专项经费资助

摘　　要：利用ICP-OES和ICP-MS,分析了麦哲伦海山群西北端MK海山2170 m水深的MKD23B-3号富钴结壳样品,获得了其剖面上Ce,Co和P2O5含量数据。结果显示,该样品未磷酸盐化壳层的过剩Ce(Cexs)与Co含量之间呈明显的正相关关系,相关系数R2高达0.7893;与生长速率呈负相关关系,相关系数R2高达0.7211,表明壳层生长速率是制约结壳Ce含量的主因,高的Ce含量是低的生长速率造成的。在假设海水pH,Mn2+等条件不变的前提下,结壳生长速率正相关于Fe,Mn的沉积通量,而Fe,Mn的沉积通量正相关于海水中溶解氧含量。因此,在海水pH,Mn2+等条件不变的前提下,Cexs负相关于海水中溶解氧含量,海水溶解氧含量只是制约结壳Ce含量的间接因素,纠正了"结壳高Ce异常指示其形成时海水中高溶解氧含量"的认识。A Co-rich Fe-Mn crust MKD23B-3 was dredged from Seamount MK of Magellan Seamount cluster at a water depth of about 2170 m,and the Ce,Co and P2O5 contents along the section of this sample were analyzed by means of ICP-OES and ICP-MS.The results exhibited that,in non-phosphatized crust layer,the excess Ce（Cexs） correlated positively with Co content and correlation coefficient R2 was as high as 0.7893,however,correlated negatively with growth rate and correlation coefficient R2 was as high as 0.7211,which suggested that growth rate was the predominant factor controlling the Ce content in this Co-rich Fe-Mn crust,and high Ce content was resulted from low growth rate.If the pH and Mn2＋ content in seawater were constant during the growth of this sample,the growth rate of Fe-Mn crusts correlates positively with the depositional flux of Fe and Mn,and the depositional flux of Fe and Mn correlates positively with the dissolved oxygen in seawater.Based on above analysis,it could be concluded that,in case of the constant pH and Mn2＋ content,Cexs correlated negatively with the dissolved oxygen in seawater,and the dissolved oxygen in seawater was an indirect controlling factor for the content of Ce in Fe-Mn crusts.This essay corrected the former conclusion that ＂the high Ce anomaly indicates the low dissolved oxygen content in seawater out of which Fe-Mn crusts deposited＂.

关 键 词：富钴结壳 过剩铈 麦哲伦海山群 稀土 

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