A late Ediacaran ice age: The key node in the Earth system evolution

Glacial depositions are widely discovered in the late Ediacaran strata all over the world, but the temporal and spatial distributions of the Ediacaran glaciations remain poorly constrained, preventing our further understanding of the nature and consequence of this ice age. In this study, we reviewed the global Ediacaran glacial depositions, the environmental changes, and biological evolution during the ice age. Available geochronological and biostratigraphic data suggest that the Ediacaran ice age might have extended from >580 Ma to <560 Ma, which is broadly coincident with a true polar wander (TPW) event with rapid rotation of continents. The TPW event may provide a possible solution for the spatiotemporal distributions of Ediacaran glaciations. Moreover, the late Ediacaran ice age bracketed the Shuram Excursion (SE), the largest negative carbonate carbon isotope excursion in Earth's history, which has been attributed to the massive oxidation of dissolved organic carbon or methane in the deep ocean, as well as witnessed the diversification of Ediacaran biota, the earliest, complex, macroscopic life forms in Earth's history. Termination of this ice age brought metazoans into the fossil records, starting the prelude of the 'Cambrian Explosion', thus implying the late Ediacaran ice age as a critical node in the history of Earth System.