Planetesimal accretion timescales inferred from Hf-W chronometry

确定内太阳系行星吸积的时间尺度对于理解行星的形成和限制控制行星后续演化的参数至关重要。短寿命核素非常适合于获得这样的年龄限制，182Hf-182W计时器已被证明在提供小行星和类地行星化学分化的时间尺度方面特别有用。该研究项目的主要目的是获得高精确的铁粒和辉化辉石球粒陨石的Hf-W年龄，并限制其母体的吸积时间尺度。球粒陨石和顽辉石球粒陨石都是在太阳星云的不同区域形成的，那里的吸积可能非常迅速。因此，了解这些陨石母体的吸积时间尺度对于理解太阳系内部的行星吸积是至关重要的。然而，关于球粒陨石和顽辉石球粒陨石年龄的信息很少，它们的吸积时间尺度也不知道。富钙铝包裹体的Hf - W定年将作为对ureites和en辉石球粒陨石年代学工作的补充，目的是更好地约束太阳系初始Hf和W同位素组成。这些参数对于精确测定陨石材料的Hf-W年龄至关重要，但目前还不够精确。

Determining the timescales of planetary accretion in the inner solar system is critical to understanding planet formation and for constraining the parameters that controlled the subsequent evolution of planets. Short-lived nuclides are well suited for obtaining such age constraints and the 182Hf–182W chronometer has proven particularly useful for providing the timescales of the chemical differentiation of asteroids and terrestrial planets. The major aim of this research project will be to obtain highly precise Hf–W ages for ureilites and enstatite chondrites and to constrain the accretion timescales of their parent bodies. Both ureilites and enstatite chondrites have formed in distinct regions of the solar nebula, where accretion may have been rapid. As such, knowing the accretion timescales of these meteorite parent bodies is essential for understanding planetary accretion in the inner solar system. However, information on the ages of ureilites and enstatite chondrites are scarce and their accretion timescales are not known. The chronological work on ureilites and enstatite chondrites will be complemented by Hf–W dating of Ca-Al-rich inclusions with the aim to better constrain the initial Hf and W isotopic compositions of the solar system. These parameters are critical for a precise determination of Hf–W ages of meteoritic materials but are currently not known sufficiently precise.