Huronian glaciation
The Huronian glaciation (or Makganyene glaciation) extended from 2400 Mya to 2100 Mya (~300 million years), during the Siderian and Rhyacian periods of the Paleoproterozoic era, following the Great Oxygenation Event (GOE), which oxidised the atmospheric methane (a greenhouse gas).
To give some temporal context to this era of glaciations, complex life on earth has only been around for 650 million years. The Huronian glaciation more or less lasted 300 million years, so about 1/2 the time there has been complex life on Earth. However, this era may have had intermittent breaks in the extent of glaciation so there are many issues of continuity.
Name origin
This geological era was named due to evidence collected from the Lake Huron region in North America where three separate horizons of glacial deposits are separated by non-glacial sediment.
Geological context
The Huronian glaciation was one of the most severe and longest ice ages in geologic history, similar to the shorter proposed Snowball Earth ice ages that happened in the Cryogenian, a geologic period that occurred 850 to 635 million years ago.[1][2][3][4]
Causes
The Huronian glaciation may have been caused by
- the oxygen catastrophe
- or by a 250 million year lull in volcanic activity which resulted in lower carbon dioxide levels and a reduced greenhouse effect
- or by the placement of the continental landmasses, as is associated as being a probable cause of the Cryogenian
- or by the way in the Earth orbited the Sun
- or by a variable combination of all of these factors, so called Perfect Storm
There is little consensus on the exact cause of the event. The Sun's output during this era was about -6% of what it is today, but this factor alone does not work as the Sun was even weaker 4 billion years ago.
In popular culture
This greatest of great geological glaciations has more or less not been covered in popular culture, even in documentary series that cover global glaciations
- There is a BBC Horizon Snowball Earth (2001) on that mentions this era in passing, but is more concerned with the Cryogean era
- The Time Travellers Guide To Australia (Australia, 2012) mentions it also in Part 1 of 4 but only in passing.
- The BBC/CBC/NHK "Miracle Planet : Snowball Earth" (2010s) episode covers this era better
- There is a NASA lecture "New and Emerging Perspectives on Late Precambrian 'Snowball Earth' Glaciation" that covers this era and several other glacial events in great detail
References
- ↑ Lane, Nick (5 February 2010). "First breath: Earth's billion-year struggle for oxygen". New Scientist (2746). A snowball period, c2.4–c2.0 Gya, triggered by the Great Oxygenation Event
- ↑ Williams G.E.; Schmidt P.W. (1997). "Paleomagnetism of the Paleoproterozoic Gowganda and Lorrain formations, Ontario: low palaeolatitude for Huronian glaciation" (PDF). EPSL 153 (3): 157–169. Bibcode:1997E&PSL.153..157W. doi:10.1016/S0012-821X(97)00181-7.
- ↑ Evans, D.A.; Beukes, N.J.; Kirschvink, J.L. (March 1997). "Low-latitude glaciation in the Palaeoproterozoic era". Nature 386 (6622): 262–6. Bibcode:1997Natur.386..262E. doi:10.1038/386262a0.
- ↑ Kopp, Robert E.; Kirschvink, Joseph L.; Hilburn, Isaac A.; Nash, Cody Z. (2005). "The Paleoproterozoic snowball Earth: A climate disaster triggered by the evolution of oxygenic photosynthesis". Proc. Natl. Acad. Sci. U.S.A. 102 (32): 11131–6. Bibcode:2005PNAS..10211131K. doi:10.1073/pnas.0504878102. PMC 1183582. PMID 16061801.
| Proterozoic Eon | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Paleoproterozoic Era | Mesoproterozoic Era | Neoproterozoic Era | |||||||
| Siderian | Rhyacian | Orosirian | Statherian | Calymmian | Ectasian | Stenian | Tonian | Cryogenian | Ediacaran |
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