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

怀俄明省暴露了最具同位素演化的太古宙克拉通之一。怀俄明省形成了北美前寒武纪地盾的早期部分，年轻的地体被吸积到那里。然而，该省的起源尚不清楚，一些同位素数据表明，它来自一个更古老的储层，如果它的U/Pb比与平均地壳相当，那么它的年龄一定超过4.0 Ga。确定古陆古储层的年龄和组成，对于理解太古宙末期古陆由高U/Pb体系向低U/Pb体系转变的过程至关重要。这项工作包括详细的地质和地球化学调查，包括SHRIMP U-Pb地质年代学，对熊齿山中至早期太古宙地壳进行了详细的地质和地球化学调查，在那里演化的同位素特征得到了最好的记录。这些结果对于限制地球早期地球化学分异过程具有重要意义。

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.