中太平洋YJA海山富钴结壳矿物组成与元素地球化学

研究样品采自马尔库斯（MARCUS）海脊YJA海山。利用等离子光谱、等离子质谱、X-射线衍射、红外光谱、场发射电镜等分析测试方法，对富钴结壳中不同构造层的矿物组成和元素地球化学进行了研究。该结壳为一大型板状新结壳，矿石矿物是水羟锰矿，脉石矿物是石英、斜长石、磷灰石等，微量矿物有蒙脱石、高岭石、钠沸石、水黑云母、片沸石等。从结壳的底部构造层到顶部构造层，TMn,Ni,Cu, Ba,Zn等元素的质量分数逐渐减少，TFe逐渐增加，Co变化不大；在相对疏松的构造层中，Si,Al,K,Na,Ca,Mg,Ti,P,Li,Rb等元素相对富集；结壳的稀土元素总量是1 982.27×10^-6，Ce具明显的正异常。不同构造层稀土元素的演化趋势是：Ce与Mn等元素相同，其他稀土元素（Y除外）与Fe等相似。

The Mineral Composition and Element Geochimestry of Co-Enriched Crust from the YJA Sea Mount in the Central Pacific Ocean

The mineral composition and the concentration of ore forming and rare earth elements of different structure layers in the Co crust from the YJA sea mount in the central Pacific ocean, were determined using ICP AES, ICP MS, XRD, FT IR and JSM. The results show that this crust is a large of plank new crust,ore mineral is vernadite, gangue minerals are quartz, plagioclase and apatite, minor minerals are montmorillonite, kaolinite, natrolite, hydrobiotite and heulandite and so on. The contents of total Mn, Ni, Cu, Ba, Zn are gradually decreased from lower to upper the structure layers while TFe increased and Co keep almost unchanged. Si, Al, K, Na, Ca, Mg, Ti, P, Li and Rb are relatively enriched in the loose structure layers. In the crust, total REE content are 1 982.27×10-6 and Ce is distinctively positive anomalies.The varied tendency of Ce is similar to Mn while other REE (excepting Y) are more like Fe.