Editing Snowball Earth (section)

===Neoproterozoic===
{{main|Sturtian glaciation|Marinoan glaciation|Baykonurian glaciation}}
There were three or four significant ice ages during the late Neoproterozoic. Of these, the Marinoan was the most significant, and the Sturtian glaciations were also widespread.<ref name=Stern2006>{{cite journal
| author = Stern, R.J. |author2=Avigad, D. |author3=Miller, N.R. |author4=Beyth, M.
| year = 2006
| title = Geological Society of Africa Presidential Review: Evidence for the Snowball Earth Hypothesis in the Arabian-Nubian Shield and the East African Orogen
| journal = [[Journal of African Earth Sciences]]
| volume = 44
|issue=1 | pages = 1–20
| doi = 10.1016/j.jafrearsci.2005.10.003|bibcode = 2006JAfES..44....1S }}</ref> Even the leading snowball proponent Hoffman agrees that the 350 thousand-year-long<ref name=Pu/> [[Gaskiers glaciation]] did not lead to global glaciation,<ref name=Hoffman2005>{{cite journal
| author = Hoffman, P.F.
| year = 2005
| title = On Cryogenian (Neoproterozoic) ice-sheet dynamics and the limitations of the glacial sedimentary record
| journal = [[South African Journal of Geology]]
| volume = 108
| pages = 557–77
| doi = 10.2113/108.4.557
| issue = 4
}}</ref> although it was probably as intense as the [[Andean-Saharan glaciation|late Ordovician glaciation]]. The status of the [[Kaigas]] "glaciation" or "cooling event" is currently unclear; some scientists do not recognise it as a glacial, others suspect that it may reflect poorly dated strata of Sturtian association, and others believe it may indeed be a third ice age.<ref name=Smith2008>{{Cite journal | last1 = Smith | first1 = A. G. | doi = 10.1144/SP326.2 | title = Neoproterozoic timescales and stratigraphy | journal =  Geological Society, London, Special Publications| volume = 326 | pages = 27–54 | year = 2009 | issue = 1 | bibcode=2009GSLSP.326...27S| s2cid = 129706604 }}</ref> It was certainly less significant than the Sturtian or Marinoan glaciations, and probably not global in extent. Emerging evidence suggests that Earth underwent a number of glaciations during the Neoproterozoic, which would stand strongly at odds with the snowball hypothesis.<ref name=nature_geo/>