Effect of light elements on the sound velocities in solid iron: Implications for the composition of Earth's core
Effect of light elements on the sound velocities in solid iron: Implications for the composition of Earth's core
复制标题
DOI：
10.1016/j.epsl.2006.11.025
复制
发表时间：
2007-02-15
影响因子：
5.3
通讯作者：
d'Astuto, Matteo
中科院分区：
文献类型：
--
作者：
Badro, James;Fiquet, Guillaume;d'Astuto, Matteo
我们测量压缩声速轻元素合金铁（FeO，FeSi，FeS和FeS 2）在高压下的非弹性X射线散射。该数据集提供了对地球核心组成的新矿物学约束，并完成了这些化合物的压力-密度系统学所形成的先前集合。基于这些数据集的组合和径向地震模型的比较，我们提出了一个地球核心的平均组成模型。我们表明，掺入少量的硅或氧是兼容的地球物理观测和地球化学丰度。镍对计算的轻元素含量的影响是可以忽略不计的。从我们的测量中得到的优选的芯模型是包含2.3重量%的内芯。硅和痕量氧，以及含有2.8重量%硅和约5.3重量%氧气(c)2006 Elsevier B. V.保留所有权利。
We measured compressional sound velocities in light element alloys of iron (FeO, FeSi, FeS, and FeS2) at high-pressure by inelastic X-ray scattering. This dataset provides new mineralogical constraints on the composition of Earth's core, and completes the previous sets formed by the pressure-density systematics for these compounds. Based on the combination of these datasets and their comparison with radial seismic models, we propose an average composition model of the Earth's core. We show that the incorporation of small amounts of silicon or oxygen is compatible with geophysical observations and geochemical abundances. The effect of nickel on the calculated light element contents is shown to be negligible. The preferred core model derived from our measurements is an inner core which contains 2.3 wt.% silicon and traces of oxygen, and an outer core containing 2.8 wt.% silicon and around 5.3 wt.% oxygen. (c) 2006 Elsevier B.V. All rights reserved.