Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4741521 | Physics of the Earth and Planetary Interiors | 2014 | 8 Pages |
Abstract
We studied partitioning of potassium (K) between aluminosilicate (adularia, KAlSi3O8) and metals with and without light elements, oxygen and silicon (Fe-O, Fe-Si, and pure Fe metals). We conducted experiments at pressures up to 50Â GPa, temperatures up to 3500Â K, and oxygen fugacities (log fO2) between 2.5 and 4.0 log units below the iron-wüstite (IW) buffer using a double-sided laser-heated diamond anvil cell. Our results on pressure, temperature, and compositional effects on partition coefficient of potassium, DK (i.e., the content of potassium in metal [wt%] divided by the content of potassium in silicate [wt%]), revealed that the temperature effect is slightly positive but weaker than that reported previously, whereas the pressure effect is negative. Oxygen in metal increases the potassium content in metal, whereas silicon in metal has the opposite effect. According to the present study on potassium partitioning, we estimated that the amount of potassium in the core is less than 40Â ppm and that it generates less than 0.17Â TW heat in the core. The amount of heat generated in the core is very small compared with the heat escaping from the core at the core-mantle boundary (5-15Â TW).
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geophysics
Authors
Kosui Watanabe, Eiji Ohtani, Seiji Kamada, Tatsuya Sakamaki, Masaaki Miyahara, Yoshinori Ito,