A recent estimate of the timing and duration of Proterozoic glacial periods. Note that great uncertainty surrounds the dating of pre-Gaskiers glaciations. The status of the Kaigas is not clear; its dating is very tentative and many researchers do not recognise it as a glaciation.[1] An earlier and longer possible snowball phase, the Huronian glaciation, is not shown here.
The Marinoan glaciation, sometimes also known as the Varanger glaciation,[2] was a period of worldwide glaciation.[3]
Its beginning is poorly constrained, but occurred no earlier than 654.5 Ma (million years ago).[4]
It ended approximately 632.3 ± 5.9 Ma[3]
during the Cryogenianperiod. This glaciation possibly covered the entire planet, in an event called the Snowball Earth. The end of the glaciation was caused by volcanic release of carbon dioxide and dissolution of gas hydrates[5]
and may have been hastened by the release of methane from equatorial permafrost.[6][7]
^ abRooney, Alan D.; Strauss, Justin V.; Brandon, Alan D.; Macdonald, Francis A. (2015). "A Cryogenian chronology: Two long-lasting synchronous Neoproterozoic glaciations". Geology. 43 (5): 459–462. Bibcode:2015Geo....43..459R. doi:10.1130/G36511.1.