Study on the primordial state of the terrestrial planets from the abundance of transition metal elements

从过渡金属元素丰度研究类地行星的原始状态

• 批准号: 05833010
• 负责人: SUZUKI Toshihiro
• 金额: $ 1.34万
• 依托单位: Gakushuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05833010/
• 关键词: Mantle-Core Separation; High Pressure; Element Partitioning

The partitioning behavior of Mn, Co and Ni between metallic iron and olivine, pyroxene and magnesiowustite were experimentally investigated at 1400ﾟC and 3-11 GPa.The effect of dissolution of hydrogen in metallic iron on the partitioning behavior was also examined. At normal pressure, it is known that Co and Ni concentrate in metallic phase and Mn concentrates in oxide phases. These siderophile and lithophile nature of these elements reduce under high pressures : all the observed metal/silicate partition coefficients, are approaching to 1 with an increase in pressure. It is also found that the effect of dissolution of hydrogen in metallic iron is very small. Since the exchange reaction with Fe can not be defined on the trivalent elements, the pressure effect on the partition behavior of these elements were not determined precisely. However, it was suggested that partition coefficient of Cr, V,In, La, Tm and Sc may be also approaching to 1 with increase in pressure.It has been pointed out that the abundance of elements in the Earth's upper mantle can not be explained by metal/silicate equilibrium consideration estimated from the partition coefficients at normal pressure. From the present experimental results, however, it is found that partition coefficients approach to 1 with increase in pressure, and the observed upper mantle elemental abundance may be explained by the equilibrium between metal/silicates under extremely high pressure. When we compare the geochemical characters of Earth, Moon, Shergottite parent body and Eucrite parent body, it is found that the apparent partition coefficients of these terrestrial planes systematically changed with change in size of the planet. These observations suggest that pressure effect on partition coefficients playd an important role for the chemical evolution of the terrestrial planets.

在1400 ℃、3-11 GPa压力下，研究了Mn、Co、Ni在金属铁与橄榄石、辉石和镁橄榄石之间的分配行为，并考察了氢在金属铁中的溶解对分配行为的影响。在常压下，已知Co和Ni富集在金属相中，Mn富集在氧化物相中。这些元素的亲铁和亲石性质在高压下降低：所有观察到的金属/硅酸盐分配系数随着压力的增加接近1。同时发现氢在金属铁中的溶解作用很小。由于与Fe的交换反应不能在三价元素上确定，因此压力对这些元素分配行为的影响不能精确确定。然而，Cr、V、In、La、Tm和Sc的分配系数也可能随压力的增加而趋于1，并指出用常压下的分配系数估算的金属/硅酸盐平衡考虑不能解释地球上地幔元素的丰度。然而，从目前的实验结果可以看出，随着压力的增加，分配系数趋于1，上地幔元素丰度可以用金属/硅酸盐在极高压力下的平衡来解释。通过对地球、月球、Shergottite母岩和Eucrite母岩地球化学特征的比较，发现这些地球平面的表观分配系数随行星大小的变化而系统地变化。这些观测结果表明，压力对分配系数的影响在类地行星化学演化中起着重要作用。

项目成果

Toshihiro Suzuki Masaki Akaogi Takehiko Yagi: "Pressure effect on Mn,Co and Ni Partitioning between iron hydride and mantle minerals" Proceedings of the Japan Academy. (in press). (1994)

Toshihiro Suzuki Masaki Akaogi Takehiko Yagi：“压力对氢化铁和地幔矿物之间锰、钴和镍分配的影响”日本科学院院刊。

鈴木敏弘: "高圧下における金属-鉱物の反応と核の組成" 高圧力の科学と技術. Vol.3. 34-40 (1994)

Toshihiro Suzuki：“高压下的金属矿物反应和核心成分”高压科学与技术第 3 卷（1994 年）。

Toshihiro Suzuki,Masaki Akaogi,Takehiko Yagi: "Pressure effect on Mn,Co,and Ni partitioning between iron hydride and Mantle minerals" Proceedings of the Japan Academy. Vol.70,Ser.B. 31-36 (1994)

Toshihiro Suzuki、Masaki Akaogi、Takehiko Yagi：“压力对氢化铁和地幔矿物之间锰、钴和镍分配的影响”日本科学院院刊。

Suzuki T., Akaogi M.and Yagi T.: "Pressure effect on Mn, Co and Ni partitioning between iron hydride and mantle minerals." Proc.Japan Acad.70, Ser B. 31-36 (1994)

Suzuki T.、Akaogi M.和 Yagi T.：“压力对氢化铁和地幔矿物之间锰、钴和镍分配的影响。”

Toshihiro Suzuki,Masaki Akaogi,Takehiko Yagi: "Pressure effect on Mn,Co and Ni Partitioning between iron hydride and mantle minerals" Proceedings of the Japan Academy. Vol.70,Ser.B. 31-36 (1994)

Toshihiro Suzuki、Masaki Akaogi、Takehiko Yagi：“压力对氢化铁和地幔矿物之间锰、钴和镍分配的影响”日本科学院院刊。