The evolution of material in the inner solar system: Elucidating the history of enstatite chondrites

太阳系内部物质的演化：阐明顽辉石球粒陨石的历史

• 批准号: 2298144
• 金额: --
• 依托单位: The Open University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2298144
• 关键词: evolution; material; inner; solar; system

The solar system formed from a disk of dust and gas, and this can be analysed using meteorites that date from this time. The student will undertake a detailed study of materials that date from this time and place - specifically the enstatite meteorites, which may have originated in the innermost part of the disk.Chondritic meteorites are relicts from the early solar system composed largely of sub-spherical um-to-mm sized objects called chondrules. Enstatite chondrites are isotopic twins to the Earth-Moon system, suggesting a genetic connection.In addition, recent orbital data from the MESSENGER mission to Mercury have shown that it has chemical similarities to the enstatite chondrites, for example high sulphur abundances and Mg/Si ratios.This rare meteorite group (only around 500 enstatite meteorites are known) are therefore highly likely to be products of the inner solar system; if not direct ancestors then possible 'aunts' to the terrestrial planets.The enstatite chondrites are remarkable for their extremely reduced mineralogy; sulphides and metal are very abundant and the main silicate is FeO-poor enstatite. Reduced C and N bearing minerals such as SiC, graphite and nierite (Si3N4) are relatively abundant. High temperature solids such as calcium aluminium-rich inclusions (CAIs) are rare.The student will analyse the chemistry and isotope systematics of individual, pristine, chondrules, CAIs and isolated sulphide grains from the most primitive available enstatite chondrites.

太阳系是由尘埃和气体组成的圆盘形成的，这可以通过这个时期的陨石来分析。学生将对这个时间和地点的材料进行详细的研究，特别是可能起源于圆盘最内部的长辉石陨石。球粒陨石是早期太阳系的遗迹，主要由um- mm大小的亚球形物体组成，称为球粒。顽辉石球粒陨石是地月系统的同位素双胞胎，这表明它们之间存在遗传联系。此外，信使号水星任务最近传回的轨道数据表明，它与顽辉石球粒陨石具有化学相似性，例如高硫丰度和高镁硅比。因此，这种罕见的陨石群（已知的顽辉石陨石只有大约500颗）极有可能是内太阳系的产物；如果不是直系祖先，那么可能是类地行星的“阿姨”。顽火辉石球粒陨石的显著特征是其矿物学极度还原；硫化物和金属非常丰富，硅酸盐主要为贫铁顽辉石。还原性含碳、含氮矿物如碳化硅、石墨、铌石（Si3N4）相对丰富。高温固体，如富钙铝包裹体（CAIs）是罕见的。学生将从最原始的顽辉石球粒陨石中分析单个、原始、球粒、cai和分离的硫化物颗粒的化学和同位素系统。