权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

A study of diffusion and partition of 3d transition metal and rare-earth elements in the rock-forming minerals

3d过渡金属和稀土元素在造岩矿物中的扩散分配研究

基本信息

批准号：
09440193
负责人：
NAGASAWA Hiroshi
金额：
$ 9.54万
依托单位：
Gakushuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

The following results have been obtained in this study. 1) A new unhydrous Cu(2)-bearing silicate mineral and a Cu(2)-bearing ortho-pyroxene have been synthesized and their structures have been analyzed by single crystal X-ray diffraction. It is found that Cu mainly occupies a 4-fold coordinated site with square planar shape, while Mg occupies a 6-fold coordinated octahedral site in the new Cu-silicate structure. In the ortho-pyroxene structure Cu(2) occupies M2 site with square pyramidal 5-fold coordinated structure. The results reflect the Jahn-Teller nature of Cu(2) ion. 2) Diffusion of CO and Ni in olivine has been measured in the temperature range of 700-1000℃. It is found that the observed diffusion coefficients are consistent with those at high temperatures in terms of Arrhenius-relation. In gehlenite Ni and CO showed unexpectedly high diffusivities with unusually high activation energies, suggesting a unique mechanism for these elements. 3) Diffusion coefficients of the rare-earth elements (REE) have been measured. Individual REE showed different diffusivities depending to their ionic radii. Eu showed, under atmospheric condition, diffusion profiles composed of two segments corresponding to significantly different diffusivities. 4) Fractionation factor of D/H between hydrated CuClィイD22ィエD2 crystal and saturated CuClィイD22ィエD2 solution has been measured. Raman spectra of CuClィイD22ィエD2 crystal have been measured, and the fractionaton factors are calculated using the partition function relations. It is found that the observed and calculated fractionation factors agree reasonably well.

本研究得到以下结果：1)合成了一种新的无水含Cu(2)硅酸盐矿物和一种含Cu(2)的正辉石，并用单晶x射线衍射对其结构进行了分析。发现在新型铜硅酸盐结构中，Cu主要占据4重配位，具有方形平面形状，而Mg主要占据6重配位的八面体位置。在正辉石结构中，Cu(2)以五重配位结构占据M2位。结果反映了Cu(2)离子的Jahn-Teller性质。2)在700 ~ 1000℃范围内测定了CO和Ni在橄榄石中的扩散。结果表明，观测到的扩散系数与高温时的扩散系数符合arrhenius关系。在辉长岩中，Ni和CO表现出异常高的扩散率和异常高的活化能，表明这些元素具有独特的机制。3)测量了稀土元素（REE）的扩散系数。不同的稀土元素表现出不同的扩散系数，这取决于它们的离子半径。Eu表明，在大气条件下，扩散曲线由两段组成，对应着显著不同的扩散系数。4)测定了水合CuCl D22 D2晶体与饱和CuCl D22 D2溶液之间的D/H分馏系数。测量了CuCl φ φ D22 φ φ D2晶体的拉曼光谱，并利用配分函数关系计算了分选因子。结果表明，实测分馏因子与计算分馏因子吻合较好。