Regional correlation, sedimentology and new U-Pb detrital zircon and whole rock Sm-Nd data: Implications for Neoproterozoic Miette Group paleogeography and provenance, southern Canadian Rocky Mountains

Abstract We present detailed stratigraphic sections from the Miette Group and a set of U-Pb detrital zircon ages obtained by Laser Ablation Multicollector-Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICPMS) from twelve samples collected throughout the Miette Group accompanied by eight whole-rock Sm-Nd data. The new Sm-Nd data show εNd(T) values between −19.1 and −22.6 and TDM ages in the 2.50 and 2.88 Ga range which indicate regionally consistent SmNd characteristics for the Miette Group. Detrital zircon ages in the Miette Group define four populations. Most zircons show a bimodal Paleoproterozoic and Neoarchean distribution pattern with variable limits and abundances. These zircon grains were sourced from the proximal Paleoproterozoic and Archean western craton. Two other small populations of Mesoproterozoic zircon grains lie in the 1176–945 Ma range (n = 20), and in the 1463–1324 Ga range (n = 5). Grains in the 1176–945 Ma range could imply a river system reaching across the continent to the Grenville Province. The youngest Paleoproterozoic zircon grains in the 1769–1658 Ma and the small number of Mesoproterozoic grains in the 1463–1324 Ma range were probably recycled from the underlying Belt-Purcell Supergroup to the south. Detrital zircon U-Pb age probability plots reveal several temporal and spatial dissimilarities within the Miette Group and significant one-sample occurrences of anomalous ages argue for denser and more systematic sampling of the Miette Group and other components of the Windermere Supergroup.