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

太阳系是由尘埃和气体的圆盘形成的，这可以用从这个时候开始的陨石来分析。学生将对这个时间和地点的物质进行详细的研究--特别是顽辉石陨石，它可能起源于圆盘的最深处。球粒陨石是早期太阳系的遗迹，主要由称为球粒的次球形微米到毫米大小的物体组成。顽火辉石球粒陨石是地球-月球系统的同位素双胞胎，暗示着一种成因联系。此外，最近信使号前往水星的轨道数据表明，它与顽火辉石球粒陨石有化学上的相似之处，例如高硫丰度和镁硅比。这种稀有的陨石群(仅有约500块顽火辉石陨石已知)很可能是太阳系内的产物；如果不是直系祖先，那么可能是地球行星的阿姨。顽火辉石球粒陨石以其极低的矿物学而引人注目；硫化物和金属非常丰富，主要硅酸盐是贫铁的顽火辉石。碳化硅、石墨和硝铁矿(Si3N4)等还原碳氮矿物相对丰富。高温固体，如富钙铝包裹体(CAI)是罕见的。学生将分析单个的、原始的、球粒陨石、CAI和最原始的顽火辉石球粒陨石中孤立的硫化物颗粒的化学和同位素系统。

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.