Dates for the Shuram excursion

One of the biggest conundrums of the Neoproterozoic is the cause of the 'Shuram' carbon isotope excursion, the largest negative carbonate carbon isotope excursion in the geologic record. In collaboration with colleagues at Yale, MIT and Dartmouth, we have helped produced new radiometric constraints on the Shuram excursion. The paper, which was published in PNAS by Alan Rooney and can be accessed here, demonstrates that the excursion occurred at the same time on multiple paleocontinents, helping constrain possible causal mechanisms. These ages also provide surprising new constraints on the evolution of the Ediacaran biota, demonstrating that the first deep-water Ediacaran organisms originated after the Gaskiers glaciation and before the Shuram excursion.