Calibrating the Cryogenian
Document Type
Article
Publication Date
3-5-2010
Abstract
The Neoproterozoic was an era of great environmental and biological change, but a paucity of direct and precise age constraints on strata from this time has prevented the complete integration of these records. We present four high-precision U-Pb ages for Neoproterozoic rocks in northwestern Canada that constrain large perturbations in the carbon cycle, a major diversification and depletion in the microfossil record, and the onset of the Sturtian glaciation. A volcanic tuff interbedded with Sturtian glacial deposits, dated at 716.5 million years ago, is synchronous with the age of the Franklin large igneous province and paleomagnetic poles that pin Laurentia to an equatorial position. Ice was therefore grounded below sea level at very low paleolatitudes, which implies that the Sturtian glaciation was global in extent.
Publication Information
Macdonald, Francis A.; Schmitz, Mark D.; Crowley, James L.; Roots, Charles F.; Jones, David S.; Maloof, Adam C.; Strauss, Justin V.; Cohen, Phoebe A.; Johnston, David T.; and Schrag, Daniel P.. (2010). "Calibrating the Cryogenian". Science, 327(5970), 1241-1243. https://doi.org/10.1126/science.1183325