太平洋铁锰结核与富Co结壳的矿物地球化学比较研究  

Comparison of the Mineral and Geochemistry Characteristics Between Co-Rich Crusts and Ferromanganese Nodules from the Pacific Ocean

作　　者：赵广涛[1] 何雨旸[1] 陈淳[1] 李德平[1] 徐翠玲[1] 陆建国[1] 吴晓[1] 

机构地区：[1]中国海洋大学海底科学与探测技术教育部重点实验室,海洋地球科学学院,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2011年第5期85-93,共9页Periodical of Ocean University of China

基　　金：国家大学生创新性实验计划项目(091042318)资助

摘　　要：本文对采自东太平洋CC区的2块不同类型的铁锰结核及中太平洋麦哲伦海山的1块富Co结壳，采用XRD和IcP—MS（AES）等分析研究方法，进行了矿物地球化学的比较研究。结果表明：铁锰结核主要由水羟锰矿及钡镁锰矿组成，富Co结壳主要以水羟锰矿为主。与2块铁锰结核相比，富Co结壳总体上Cu、Al、Na含量较低而Co含量较高；两块不同类型的结核相比较，水成型铁锰结核的P、Ti含量较高，而成岩型铁锰结核的Cu、Ni含量较高。3块样品的稀土元素含量均较高，为（521．8～1424．15）×10^-6。REE分布型式总体呈平缓型，（La／Yb）20为0．72～1.01，并具程度不同的Ce、Eu正异常。经估算，富Co结壳的生长速率为1．92～4．24mm／Ma，水成型铁锰结核的生长速率为1．31～14．29mm／Ma，成岩型铁锰结核的生长速率为¨．24~76．32mm／Ma。并根据铁锰结核的化学成分变化推测了其生长环境的变化。Two different ferromanganese nodule samples were collected from CC area in the east pacific, one Co-rich crust sample was collected from Magellan seamounts in the west pacific. Various observations and different analytical techniques including electron microprobe analysis, X-ray diffraction （XRD） and ICP-MS （AES） were used in the study. According to the data, Vernadite and Todorokite are the main compositions of ferromanganese nodules, while the Co-rich crust mainly consists of Vernadite. Compared with each other, hydrogenic ferromanganese nodule has higher amount of P, Ti, whereas Cu, Ni in diage- netic ferromanganese nodule is higher. The Co-rich crust is depleted in Cu, A1, Na, and rich in Co, compared with ferromanganese nodule samples. The samples are rich in Fe, Mn, Cu, Co, Ni. The content of REI; （rare earth elements） is high and the distribution of the REE elements shows positive anomaly of Ce and Eu in all the samples. Growth rates calculated by the ratio of Mn/Fe and the content of Co in these samples show that they are 1.92~4. 24 mm/Ma in Co-rich crust, 1. 31414. 29 mm/Ma in hydrogenic fer- romanganese nodule and 11.24~76.32 mm/Ma in diagenetic ferromanganese nodule respectively. Ele- ments correlation of Mn-Fe （Cuq-Ni）×10 suggests the origin of the samples.

关 键 词：多金属结核 富Co结壳 矿物学 地球化学:生长速率 成因 太平洋 

分 类 号：P595[天文地球—地球化学]