Regional and global chemostratigraphic correlation of the early Neoproterozoic Shaler Supergroup, Victoria Island, Northwestern Canada

Abstract

High resolution inorganic carbon isotope stratigraphy provides a new tool for correlating the Neoproterozoic Shaler Supergroup with the Mackenzie Mountains Supergroup. Previous stratigraphic studies established a widely accepted basis for correlation between the two supergroups. This contribution introduces a revised, testable hypothesis for the correlation of the Shaler and Mackenzie Mountains supergroups, based on matching distinctive features in the Shaler Supergroup δ 13 C data with the previously published δ 13 C curve for the Mackenzie Mountains Supergroup. The hypothesis suggests that some lithologically similar units in the two basins were deposited diachronously, and that a significant disconformity may exist within the Wynniatt Formation of the Shaler Supergroup. An important implication of the newly proposed correlation is that the flora and fauna of the Wynniatt Formation predate the “Bitter Springs” isotopic stage, placing a new constraint on the chronology of the Neoproterozoic fossil record.