[S-IT21] 核-マントルの相互作用と共進化

[SIT21-17] Some technological developments in high temperature generation using KMA and precise melting/phase relations of minerals and rocks under deep mantle conditions

*入舩 徹男^1,2、周 佑黙¹、有本 岳史¹、桑原 秀治¹、野村 龍一³、西 真之¹、山口 桃子¹、丹下 慶範⁴、栗林 貴弘⁵、劉 兆東⁶ (1.愛媛大学地球深部ダイナミクス研究センター、2.東京工業大学地球生命研究所、3.京都大学白眉センター/大学院人間・環境学研究科、4.高輝度光科学研究センター利用研究促進部門、5.東北大学理学研究科、6.吉林大超硬材料研究所)

キーワード：下部マントル、マルチアンビル装置、融解関係、相関係、高温高圧実験、技術開発

Technological developments in stable and homogeneous high temperature generation have been made using conventional LaCrO₃ or Re heater for Kawai-type multianvil apparatus (KMA) with tungusten carbide (WC) and sintered diamond (SD) anvils. For WC-KMA, stable temeperature generation to ~3000 K has been achieved under the pressures up to ~27 GPa mainly for quench experiments. Temperatures of ~2000-2300 K have been produced stably for 20-180 minutes at pressures to ~65 GPa for in situ X-ray measurements using SD-KMA, in addition to the ex situ experiments.

Some experimental studies for precise determination of subsolidus and melting phase relations have successfully been made for some simple mineral systems, such as MgSiO₃-Al₂O₃, MgSiO₃-FeSiO₃, MgSiO₃-CaSiO₃, CaSiO₃-SiO₂, Al₂O₃-SiO₂, KAlSi₃O₈-NaAlSi₃O₈, Al₂SiO₅, Ca₃Al₂Si₃O₁₂, etc. at temperatures near and above the typical geotherm at pressures corresponding to those of the mantle transition region to the middle part of the lower mantle. These studies have provided firm experimental databases for the mineralogy of the deep mantle, and also led to findings of some new high-pressure phases stable only under the very high-temperture conditions. Melting and associated partioning of some key trace elements in more complex chemical compositions have also been conducted under the pressures of the uppermost lower manlte to constrain the differentiation and evolution of the deep mantle.