The stratigraphic expression of a large negative carbon isotope excursion from the Ediacaran Johnnie Formation, Death Valley

► Carbon and oxygen isotopes were measured in Neoproterozoic strata of Death Valley. ► Data reveal the basin-scale expression of a large negative carbon isotope excursion. ► The data exhibit a north south trend when overlain on a palinspastic reconstruction. ► This lends support to hypotheses that these excursions reflect changes in marine DIC.