Reaction of metallic iron and minerals under high pressure and its implications for the composition of the Earth's core

金属铁和矿物在高压下的反应及其对地核组成的影响

• 批准号: 08640534
• 负责人: SUZUKI Toshihiro
• 金额: $ 1.54万
• 依托单位: Gakushuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640534/
• 关键词: Earth's Core; High pressure experiment

Using 6-8 type high-pressure apparatus, the high pressure experiments on the reaction of silicate minerals and metallic iron was performed at 10-15 GPa, and the solubility of light elements, such as oxygen and silicon, in metallic iron was investigated. At above 2000ﾟC,silicates and metallic iron were in liquid state. The specimen was quenched and recovered to normal pressure-temperature condition, and their texture and chemical compositions were examined.Dendritic textures and spherical grains were found in the metallic grain of recovered specimen at 15GPa. The dendritic textures show that these FeO grains were exsolved from molten metallic iron, and spherical FeO grains are regarded as the crystallized immissible oxygen rich liquid. The amount of dissolved oxygen in the metallic liquid iron was estimated to be about 10wt%. However, the amount of dissolved silicon in the molten iron is very small. Itwas also found that the amount of dissolved oxygen in the metallic phase is largely depend on the composition of the coexisting silicate liquid. The solved oxygen in the metallic phase decreased with the decrease of FeO content of the coexisting silicate liquid. At 10GPa, the amount of dissolved oxygen in the metallic phase was very small, and only hydrogen was dissolved in the molten iron.Unforunately, we have no mateal that do not react with metallic iron and silicates. Hence the specimens of the present experiments were reacted with the sample chamber and/or heating element. In order to reveal the nature of reaction between metallic iron and silicates under high pressures, further developments are required for the sample capsule and sample heating technique.

利用6-8型高压装置，在10-15 GPa的高压条件下对硅酸盐矿物与金属铁的反应进行了实验，研究了氧、硅等轻元素在金属铁中的溶解度。在2000℃以上，硅酸盐和金属铁呈液态。将试样淬火后恢复到常压-温状态，并对试样的组织和化学成分进行了检测。在15GPa下，回收试样的金属晶粒中存在枝晶织构和球形晶粒。枝晶织构表明，这些FeO晶粒是从金属铁中析出的，球形FeO晶粒是结晶化的不允许富氧液体。据估计，金属液态铁中溶解氧的含量约为10%。然而，在铁水中溶解的硅的量是非常少的。研究还发现，金属相中溶解氧的数量在很大程度上取决于共存的硅酸盐液体的组成。随着共存硅酸盐液体中FeO含量的降低，金属相中溶解氧减少。在10GPa时，金属相中溶解氧的含量非常少，只有氢溶解在铁液中。不幸的是，我们没有不与金属铁和硅酸盐反应的材料。因此，本实验的样品与样品室和/或加热元件反应。为了揭示金属铁和硅酸盐在高压下的反应性质，需要进一步发展样品胶囊和样品加热技术。

项目成果

Kubo, A, T.Suzuki snd M.Akaogi: "High pressure pahse equilibria in the system CaTiO_3-CaSiO_3: Stability of perovskite solid solutions" Physics and Chemistry of Minerals. 24. 488-494 (1997)

Kubo, A, T.Suzuki snd M.Akaogi：“CaTiO_3-CaSiO_3 系统中的高压相平衡：钙钛矿固溶体的稳定性”《矿物物理与化学》。

Akaogi,M.,H.Kojitani,K.Matsuzaka,T.Suzuki and E.Ito: "Postspinel transformations in the system Mg_2SiO_4-Fe_2SiO_4:Element partitioning,calorimetry,and thermodynamic calculation" High Pressure-High Temperature Research:Properties of Earth and Planetary Ma

赤尾木，M.，H.Kojitani，K.Matsuzaka，T.Suzuki和E.Ito：“Mg_2SiO_4-Fe_2SiO_4系统中的后尖晶石转变：元素分配，量热和热力学计算”高压高温研究：地球的性质

Akaogi, M., H.Kojitani, K.Matsuzaka, T.Suzuki and E.Ito: "Postspinel transformations in the system Mg_2SiO_4 -Fe_2SiO_4 : Element partitioning, calorimetry, and thermodynamic calculation." High Pressure-High Temperature Research : Properties of Earth and

Akaogi, M.、H.Kojitani、K.Matsuzaka、T.Suzuki 和 E.Ito：“Mg_2SiO_4 -Fe_2SiO_4 系统中的后尖晶石转变：元素分配、量热法和热力学计算。”

Suzuki, T., M. Akaogi and T.Yagi: "Pressure dependence of Ni,Co and Mn partitioning between iron hydride and olivine, magnesiowustite and pyroxene" Physics of the Earth and Planeary Interiors. 96. 209-220 (1996)

Suzuki, T.、M. Akaogi 和 T.Yagi：“氢化铁和橄榄石、镁方铁矿和辉石之间 Ni、Co 和 Mn 分配的压力依赖性”地球和行星内部物理学。

Suzuki, T.and M.Akaogi: "Element partitioning between some mantle minerals and the coexisting silicate melt under high pressure." High Pressure-High Temperature Research : Properties of Earth and Planetary Materials. Amer. Geophys. Union Monograph. (in pr

Suzuki, T. 和 M.Akaogi：“高压下一些地幔矿物与共存硅酸盐熔体之间的元素分配。”