Formation of FeNi metal nodules in the Jilin H5 chondrite, the largest stone meteorite in the world

• 作者: OA Xiande Xie Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials Guangzhou Institute of Geochemistry Chinese Academy of Sciences
• 来源期刊: 地球化学学报(英文）
• 学科: 地球科学
• 年，卷（期）: 2025,（6）
• 页码范围: 1-10
• 页数: 10页
• 语种: 中文

摘要

The Jilin H5 chondrite, the largest known stony meteorite in the world, with its No.1 fragment weighing1770 kg. It contains submillimeter-to centimeter-sized FeNi metal particles/nodules. Our optical microscopic and electron microprobe analyses revealed that the formation of metal nodules in this meteorite is a complex and long-term process, The early stage is the thermal diffusion-caused migration and concentration of dispersed metallic material along fractures to form root-hair shaped metal grains during thermal metamorphism of this meteorite. The later two collision events experienced by this meteorite led to the further migration and aggregation of metallic material into the shock-produced cracks and openings to form largersized metal grains. The shock-produced shear movement and frictional heating occurred in this meteorite greatly enhanced the migration and aggregation of metallic material to form the large-sized nodules. It was revealed that the metal nodule formation process in the Jilin H5 chondrite might perform in the solid or subsolidus state, and neither melting of chondritic metal grains nor shock-induced vaporization of bulk chondrite material are related with this process.