Partitioning of potassium between iron and silicate at the core-mantle boundary
Partitioning of potassium between iron and silicate at the core-mantle boundary
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DOI：
10.1029/2005gl025324
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发表时间：
2006-04-19
影响因子：
5.2
通讯作者：
Kikegawa, T
中科院分区：
文献类型：
--
作者：
Hirao, N;Ohtani, E;Kikegawa, T
在地球深处2900 km的地核-地幔边界（CMB）条件下，在激光加热的金刚石-砧细胞（LHDAC）中研究了金属铁和硅酸钾之间的化学反应和钾的分配。利用聚焦离子束（FIB）技术在134gpa和3500 K条件下对回收样品进行了透射电镜（ATEM）分析，发现钾（0.8 wt.%）溶解在铁水中，表明钾在铁和硅酸盐之间的分配系数为0.15。我们的研究结果表明，地核可以含有35ppm的总钾，即4.1x10(-3) ppm的（40）K，它可以作为相当于0.23 TW的地核热源。
Chemical reactions and the partitioning of potassium between metallic iron and potassium-silicate were studied at the core-mantle boundary (CMB) condition, 2900 km deep in the Earth, in a laser-heated diamond-anvil cell (LHDAC). Analytical transmission electron microscope (ATEM) analysis of the recovered samples from 134 GPa and 3500 K, prepared with Focused Ion Beam (FIB) techniques, revealed significant dissolution of potassium (0.8 wt.%) into molten iron, indicating that the partition coefficient of potassium between iron and silicate is 0.15. Our results show that the Earth's core can contain 35 ppm total potassium, i.e., 4.1x10(-3) ppm of (40)K, which could serve as a heat source corresponding to 0.23 TW in the Earth's core.