{{Short description|Last major glacial event of the Precambrian}}{{Snowball Earth timeline}}The '''Gaskiers glaciation''' is a period of widespread [[glacial deposit]]s (e.g. [[diamictite]]s) that lasted around 250,000 years, between 579.88 ± 0.44 and 579.63 ± 0.15 million years ago<ref name="eb">{{cite journal|doi=10.1130/G38284.1|title=Dodging snowballs: Geochronology of the Gaskiers glaciation and the first appearance of the Ediacaran biota|journal=Geology|volume=44|issue=11|pages=955|year=2016|last1=Pu|first1=Judy P.|last2=Bowring|first2=Samuel A.|last3=Ramezani|first3=Jahandar|last4=Myrow|first4=Paul|last5=Raub|first5=Timothy D.|last6=Landing|first6=Ed|last7=Mills|first7=Andrea|last8=Hodgin|first8=Eben|last9=MacDonald|first9=Francis A.|bibcode=2016Geo....44..955P}}</ref> — i.e. late in the [[Ediacaran]] Period — making it the last major glacial event of the [[Proterozoic]].<ref>F. M. Gradstein, Gabi Ogg, Mark Schmitz, ''The Geologic Time Scale'', Elsevier, 2012, p.&nbsp;428.</ref> It was also the last and the shortest of at least three major ice ages in the [[Neoproterozoic]] era. It is assumed that, in contrast to the [[Sturtian glaciation|Sturtian]] and [[Marinoan glaciation|Marinoan]] glaciations, it did not lead to global glaciation ("[[Snowball Earth]]").<ref name="VernhetEtAl2012" />

Deposits attributed to the Gaskiers — assuming that they were all deposited at the same time — have been found on eight separate [[paleocontinent]]s, in some cases occurring close to the [[equator]] (at a latitude of 10–30°). The {{convert|300|m|ft|adj=mid|-thick|0}} name-bearing section at [[Gaskiers-Point La Haye|Gaskiers]] ([[Newfoundland (island)|Newfoundland]]) is packed full of striated [[dropstone]]s.<ref name="eb"/> Its {{delta|13|C|link}} values are very low (pushing {{Per thousand|8|1000}}), consistent with a period of environmental abnormality.<ref name="eb"/> The bed lies just below some of the oldest fossils of the [[Ediacaran biota]], leading to early suggestions that the passing of the glaciation and the subsequent sharp rise in the [[oxygen]] levels in the ocean may have paved the way for the evolution of these odd organisms.<ref name="Canfield DE et al. (2007)">{{cite journal |author=D. E. Canfield, S. W. Poulton, G. M. Narbonne |title=Late-Neoproterozoic deep-ocean oxygenation and the rise of animal life |journal=Science |volume=315 |issue=5808 |pages=92–95 |date=January 2007 |pmid=17158290 |doi=10.1126/science.1135013|s2cid=24761414 |doi-access=free |bibcode=2007Sci...315...92C}}</ref> More accurate dating methods have shown that there is a 9-million-year gap between the diamictites and the 570 million year old macrofossils.<ref name="eb"/>

The '''Bou-Azzer glaciation''', an Ediacaran glaciation known from evidence collected from the [[West African craton|West African Craton]], may be equivalent to the Gaskiers glaciation. Alternatively, it has also been suggested to have been part of a glacial event later in the Ediacaran.<ref name="VernhetEtAl2012">{{cite journal |last1=Vernhet |first1=E. |last2=Youbi |first2=N. |last3=Chellai |first3=E. H. |last4=Villeneuve |first4=M. |last5=El Archi |first5=A. |date=February 2012 |title=The Bou-Azzer glaciation: Evidence for an Ediacaran glaciation on the West African Craton (Anti-Atlas, Morocco) |url=https://www.sciencedirect.com/science/article/abs/pii/S030192681100249X |journal=[[Precambrian Research]] |volume=196-197 |pages=106–112 |doi=10.1016/j.precamres.2011.11.009 |bibcode=2012PreR..196..106V |access-date=17 December 2022 |url-access=subscription}}</ref>

== Notes == {{notelist}}

== References == {{reflist}}

{{Ice Ages}}

[[Category:Ediacaran geology]] [[Category:Ice ages]] [[Category:Glaciology]]

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