Interaction between iron and post‐perovskite at core‐mantle boundary and core signature in plume source region
Interaction between iron and post‐perovskite at core‐mantle boundary and core signature in plume source region
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DOI：
10.1029/2006gl026868
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发表时间：
2006-08
影响因子：
5.2
通讯作者：
T. Sakai;T. Kondo;E. Ohtani;H. Terasaki;N. Endo;Toshiko Kuba;Toshiaki Suzuki;T. Kikegawa
中科院分区：
文献类型：
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作者：
T. Sakai;T. Kondo;E. Ohtani;H. Terasaki;N. Endo;Toshiko Kuba;Toshiaki Suzuki;T. Kikegawa
下地幔和地核之间的相互作用对于理解核地幔边界（CMB）D”层的性质至关重要。在这里，我们报道了后钙钛矿（PPv）和金属铁在 CMB 条件下的反应，例如 139 GPa 和 3000 Kelvin。分析型透射电子显微镜 (ATEM) 分析表明，铁水中可溶解高达 6.3 重量百分比 (wt.%) 的大量氧和高达 4.0 重量% 的硅。 PPv与铁水之间的二面角为67度。因此，大约 2 体积百分比 (vol.%) 的少量核心金属可以被捕获而不会在 CMB 处的 PPv 区域中分离。这种机制捕获的地核金属量可以在下地幔底部的羽流源中产生外核的同位素特征。
Interaction between the lower mantle and core is essential for understanding the nature of D″ layer at the core‐mantle boundary (CMB). Here, we report the reaction between post‐perovskite (PPv) and metallic iron under the condition of the CMB, for example, 139 GPa and 3000 Kelvin. Analytical transmission electron microscope (ATEM) analysis revealed that significant amount of oxygen up to 6.3 weight percent (wt.%) and silicon up to 4.0 wt.% can be dissolved into molten iron. The dihedral angle between PPv and molten iron is 67 degrees. Thus, a small amount of core metal of about 2 volume percent (vol.%) can be trapped without separation in the PPv region at the CMB. The amount of core metal trapped by this mechanism can produce the isotopic signature of the outer core in the plume source at the base of the lower mantle.