SEDIMENTARY GEOCHEMISTRY OF THE TONIAN DOLORES CREEK FORMATION, YUKON, CANADA: INVESTIGATING EARLY NEOPROTEROZOIC PALEOENVIRONMENTAL CONDITIONS

The early Neoproterozoic represents a critical period in Earth history due to the origin of many eukaryotic groups including animals. To better understand this relationship between environmental change and biotic evolution, we analyzed the sedimentary geochemistry of the Neoproterozoic Dolores Creek Formation exposed in the Wernecke Mountains in Yukon, Canada. The Dolores Creek Formation represents a succession of dark siltstone and shale interpreted to have been deposited on a prograding shelf. Shales from the upper Dolores Creek Formation have yielded a Re-Os geochronology age of 896 ± 45 Ma. In particular, we analyzed major element and redox-sensitive trace metal concentrations, total organic carbon concentrations, and iron speciation. The results of these analyses in comparison to similar studies will aid in reconstructing the paleoredox conditions of the basins of northwest Laurentia and in understanding environmental change in the early Neoproterozoic. Finally, this data will be combined with data from the Sedimentary Geochemistry and Paleoenvironments Project Phase 2 data release in order to track paleoredox change from the Neoproterozoic to early Paleozoic.