U-Pb Geochronology of the Wildhorse Gneiss Complex, Pioneer Mountains Core Complex, South-Central Idaho

美国爱达荷州立大学师生对美国爱达荷州先锋山岩心杂岩中新古宙地层进行了综合野外、岩石学、地球化学和地质年代学研究。以前对古生代地层的研究已经发现了一个不寻常的年龄在750到600 Ma之间的碎屑锆石群。这个年代的岩石在北美西部边缘非常罕见。野外考察发现，这些岩石的明显来源是先锋山脉。这项研究利用学生项目来确定这些岩石的来源并确认它们的同位素年龄。这项工作对罗迪尼亚古地理重建和雪球地球假说的评价具有重要意义。

Faculty and students from Idaho State University are engaged in integrated field, petrographic, geochemical, and geochronologic study of Neoproterozoic strata exposed in the Pioneer Mountains core complex of Idaho. Previous studies of Paleozoic strata have identified an unusual population of detrital zircons with ages of about 750 to 600 Ma. Rocks of this age are very unusual along the western margin of North America. Fieldwork has traced the apparent origin of these rocks to the Pioneer Mountains. This study utilizes student projects to determine the source of these rocks and confirm their isotopic ages. The work has implications for paleogeographic reconstructions of Rodinia and evaluation of the Snowball Earth hypothesis.