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.

这项研究已获得以下结果。 1）一种新的不溶解的Cu（2） - 含硅酮矿物质和Cu（2） - 含有原孔氧烯已合成，已经通过单晶X射线衍射对其结构进行了分析。发现CU主要占据了一个具有方形平面形状的4倍协调位置，而MG在新的Cu-Silicate结构中占据了6倍协调的八面体位置。在邻苯二甲烯结构中，Cu（2）占据了M2位点，具有5倍配位结构。结果反映了Cu（2）离子的Jahn-Teller性质。 2）在700-1000℃的温度范围内测量了CO和Ni在橄榄石中的扩散。发现观察到的扩散系数与ARRHENIUS相关性的高温下的扩散系数一致。在Gehlenite中，Ni和Co在异常高的激活能量中表现出了出乎意料的高差异，这表明了这些元素的独特机制。 3）已经测量了稀土元件（REE）的扩散系数。单个REE根据其离子半径显示出不同的差异。欧盟在大气条件下显示了差异，该差异由两个片段组成，对应于明显不同的差异。 4）水合CUCL D22E D2晶体和饱和CUCL D22E D2溶液之间D/H的分级因子已被测量。 CUCL D22E D2晶体的拉曼光谱已经测量，并使用分区功能关系计算了分数因子。发现观察到的分馏因子相当吻合良好。