原著論文
超臨界条件下におけるカンラン石と塩化物水溶液間の元素分配に関する実験
2000 年 29 巻 3 号 p. 85-96
詳細
2000 年 29 巻 3 号 p. 85-96
Experiments on the partitioning of Mg2+, Ca2+, Mn2+, Fe2+, Co2+, Ni2+ and Zn2+ between olivine (forsterite and fayalite) and 2 N aqueous chloride solutions were performed in the temperature range of 500 to 800°C, 1 kb.
The partition coefficient, which is defined as KPN(Fo)=(XMe2SiO4/XMg2SiO4)/(mMeCl2°aq/mMgCl2°aq) or KPN(Fa)=(XMe2SiO4/XFe2SiO4)/(mMeCl2°aq/mFeCl2°aq), vs. ionic radius (PC-IR) diagrams are drawn based on the experimental results. In the case of forsterite, the PC-IR curve has a local maximum near Ni2+ and shows a concave curve in the region of larger ionic size. However Zn2+ deviates from such a trend. In the case of fayalite, the PC-IR curve shows a convex curve with a peak near Ni2+ except for 500°C. Also in this case, Zn2+ deviates from such a trend. The anomaly of Zn2+ may be attributable to its tetrahedral site preferency. The KPN value for Ni2+ decreases with increasing temperature, whereas those for the other elements except for Ca2+ increase. The optimum ionic radius for forsterite and fayalite seem to increase slightly with increasing temperature.
