UBC Theses and Dissertations
Geochronology of the Clachnacudainn Gneiss, located near Revelstoke, B.C. Birnie, David John
K-Ar biotite ages and Rb-3r mineral isochron ages indicate that a 55 m. yr. old Tertiary thermal event has affected the rocks of the Clachnacudainn Salient of the Shuswap Metamorphic Complex. An attempt was made to date the Clachnacudainn Gneiss by the Rb-Sr whole rock method. It was hoped that this study would provide some insight into the problem of determining the origin of the gneiss. However, the data shows considerable scatter with no systematic pattern to it. This, together with petrographic evidence, suggests that the closed system assumption has not been maintained. Thus no isochron could be determined. Several suggestions are presented to account for the scatter in the data.
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