各类陨石中的54Cr/52Cr比值有着很系统的变化。对变化的原因目前还不十分清楚。一个可能就是这个变化反映了富集54Cr的载体在太阳系中与时间有关的不均匀分布。本项目拟在建立与发展高精度Cr同位素分析方法的基础上，系统测量碳质球粒陨石的Cr同位素组成，结合C的含量和Zn/Si比值进一步了解陨石的54Cr异常与陨石的挥发性的关系；通过对不同变质程度的CK球粒陨石的Cr同位素分析来研究54Cr异常与变质程度的关系；还计划系统研究各类球粒陨石中球粒的54Cr异常，并结合53Mn-53Cr球粒内部定年来研究54Cr异常与形成时间的关系。本项目拟通过以上研究对太阳系中54Cr异常的变化提供新的制约。

The variations in 54Cr/52Cr ratio are very systematic among different meteorite classes. The reason for these variaitons is not very clear. One possibility is that these variations reflect temporal heterogeneity in the distribution of 54Cr-rich carrier in the Solar nebula. This project is intended, on the basis of developing a high-precision method for Cr isotopic analyses, to systematically study the Cr isotopic compositions of carbonaceous chondrites,combined with C content and Zn/Si, to constrain the correlation between 54Cr anomaly and the volatility of the sample. The Cr isotopic compositions of CK chondrites with different metamorphic degrees will also be measured to constrain the relationship of 54Cr anomaly with metamorphic degree. We also want to systematically study the 54Cr anomalies of chondrules from various chondrite classes, combined with 53Mn-53Cr internal isochron, to test the possible correlation between 54Cr anomaly and the formation time. This project is intended to provide new constraints on the variations in the 54Cr anomaly in the Solar System through the approaches above.