Joint 69th Annual Southeastern / 55th Annual Northeastern Section Meeting - 2020

Paper No. 50-1
Presentation Time: 1:30 PM-5:30 PM

GEOCHEMICAL CONSTRAINTS ON THE PROVENANCE OF EDIACARAN-CAMBRIAN SEDIMENTARY ROCKS FROM THE SOUTHWESTERN MARGIN OF LAURENTIA


WEBB, L.C.1, NELSON, L.L.1, MILLIKIN, A.E.G.2, HODGIN, E.B.3, ROONEY, A.D.2 and SMITH, E.F.1, (1)Department of Earth and Planetary Sciences, Johns Hopkins University, 3400 N. Charles Street, BALTIMORE, MD 21218, (2)Department of Geology and Geophysics, Yale University, 210 Whitney Ave., New Haven, CT 06511, (3)Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138

The break-up of the supercontinent Rodinia is often mechanistically linked to coeval changes in Neoproterozoic–Cambrian surface conditions, climate, and life, yet the timing and nature of this tectonic evolution remain debated topics. Calibration of the rift to drift transition along the western (present-day coordinates) margin of Laurentia has remained particularly contentious with suggestions ranging over a hundred million years from the early Ediacaran to the middle Cambrian. We present high resolution whole rock εNd and trace element geochemical data of fine-grained clastic rocks from late Ediacaran–Cambrian str­atigraphic sections in southwestern North America. This study aims to use these geochemical data to understand temporal changes in sedimentary provenance that may be associated with the weathering of rift-related volcanic rocks along this margin.