Kyushu University Department of Earth and Planetary Sciences, Faculty of Sciences
Kyushu University Department of Earth and Planetary Sciences, Faculty of Sciences
Kyushu University Department of Earth and Planetary Sciences, Faculty of Sciences
Kyushu University Department of Materials Sciences and Engineering, Faculty of Sciences
Kyushu University Department of Materials Sciences and Engineering, Faculty of Sciences
Kyushu University Department of Earth and Planetary Sciences, Faculty of Sciences
出版者
宇宙航空研究開発機構宇宙科学研究本部
出版者（英）
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)
雑誌名
第28回月・惑星シンポジウム
雑誌名(英)
Proceedings of the 28th ISAS Lunar and Planetary Symposium
ページ
169 - 172
発行年
1995-12
抄録（英）
Spherules isolated from deep sea sediments were analyzed for chemical compositions. Three types of internal texture are observed in Ni-bearing I-type spherules: Ni free Fe oxide mantle with Fe-Ni metallic core, Fe-Ni oxide mantle with Fe-Ni metallic core and Fe-Ni oxide spherules without metallic core. Numerical simulation was performed in order to estimate variation of temperatures and radii of I-type spherules, and the force of inertia exerted on them entering the atmosphere. From the result of the simulation, it is figured out that spherules lose more than 90 percent of their original mass by ablation over 1,900 C and that the force of inertia is maximum at last stage of evaporation. Based on the observations of I-type spherules and the numerical simulation of their formation, we propose a model of the formation process of I-type spherules: during ablation, metallic core is off-centered, then surface of the core is exposed to the air due to the strong force of inertia and oxidation reaction might proceed from the exposed core surface.
Numerical simulation of 1-type spherule formation
