COLLABORATIVE RESEARCH: Early Archean Crustal Evolution in the Northern Wyoming Province

怀俄明州暴露了一个 同位素演化的太古宙古生子 怀俄明州 形成了北美前寒武纪的早期部分 盾牌，年轻的人被附在上面。 然而，在这方面， 该省的起源尚不清楚， 数据表明它来自一个更古老的水库 如果U/Pb比为 与平均地壳相比。 确定年龄和 这一古老储层的组成对于 理解导致转变的过程 这个克拉通从一个较老的，相对较高的U/Pb系统， 在太古代末期形成了一个低U/Pb体系。 工作 包括详细的地质和地球化学调查， 包括SHRIMP U-Pb年代学， 熊牙山脉的太古代地壳 同位素特征是最好的记录。 结果将 重要的是，在限制地球的过程中， 早期地球化学分异

The Wyoming Province exposes one of the most isotopically evolved Archean cratons. The Wyoming Province forms an early part of the north American Precambrian shield, to which younger terranes were accreted. However, the origin of the province is unclear, with some isotopic data suggesting that it was derived from an older reservoir that must have been older than 4.0 Ga if it U/Pb ratio was comparable to average crust. Determining the age and composition of this older reservoir is crucial for understanding the processes that lead to the transformation of this craton from an older, relatively high U/Pb system to a low U/Pb system by the end of the Archean. The work involves a detailed geologic and geochemical investigation, including SHRIMP U-Pb geochronology, of the Middle to Early Archean crust in the Beartooth Mountains where the evolved isotopic signature is best documented. Results will be important in constraining the processes involved in Earth's early geochemical differentiation.