NEW RE-OS AND U-PB AGE CONSTRAINTS FOR THE BIOLOGICAL INNOVATIONS AND GEOCHEMICAL AND CLIMATIC PERTURBATIONS OF THE NEOPROTEROZOIC (Invited Presentation)

Over the past two decades a renewed interest in the Neoproterozoic Era (1000-541 Ma) has led to the recognition of globally synchronous and long-lived (multi Myr) glacial episodes, large-scale shifts in many geochemical cycles, and biological innovations that ushered in increased ecological niche complexity. All of these biogeochemical and climatic upheavals took place during the final assembly and subsequent rifting of the Rodinia supercontinent. Unraveling the tempo of interactions between tectonics, oscillating marine redox cycles and biology is essential in order to better understand the drivers of evolutionary developments during this critical period of Earth history. Of particular interest is the paleoenvironmental context and timing of eukaryotic diversification in the lead up to the Sturtian glaciation. A paucity of radiometric age constraints has hindered our efforts to refine the temporal framework of these environmental and evolutionary events and global correlation schemes for Neoproterozoic sedimentary successions. Here we present new U-Pb zircon and Re-Os sedimentary rock and sulfide geochronological data from multiple locations. Coupled with mineralogical, geochemical, and paleontological datasets, these new age constraints enable us to more fully understand the role of tectonic and/or environmentally driven change that triggered the biological and geochemical transformations of the Neoproterozoic Era.