The Gaskiers glaciation is a period of widespread

glacial deposit image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

s (e.g.

diamictite Diamictite (; from Ancient Greek ''δια'' (dia-): ''through'' and ''µεικτός'' (meiktós): ''mixed'') is a type of lithified sedimentary rock that consists of nonsorted to poorly sorted terrigenous sediment containing particles that r ...

s) that lasted under 340 thousand years, between 579.63 ± 0.15 and 579.88 ± 0.44 million years ago — i.e. late in the

Ediacaran Period The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...

— making it the last major glacial event of the

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of th ...

.F. M. Gradstein, Gabi Ogg, Mark Schmitz, ''The Geologic Time Scale'', Elsevier, 2012, p. 428. It was also the last and the shortest of at least three major ice ages in the

Neoproterozoic The Neoproterozoic Era is the unit of geologic time from 1 billion to 538.8 million years ago. It is the last era of the Precambrian Supereon and the Proterozoic Eon; it is subdivided into the Tonian, Cryogenian, and Ediacaran periods. It is prec ...

era. It is assumed that, in contrast to the

Sturtian The Sturtian glaciation was a Snowball Earth glaciation, or perhaps multiple glaciations, during the Cryogenian Period when the Earth experienced repeated large-scale glaciations. The duration of the Sturtian glaciation has been variously defined, ...

and Marinoan periods, it did not lead to global glaciation ("

Snowball Earth The Snowball Earth hypothesis proposes that, during one or more of Earth's icehouse climates, the planet's surface became entirely or nearly entirely frozen. It is believed that this occurred sometime before 650 M.Y.A. (million years ago) du ...

"). Deposits attributed to the Gaskiers — assuming that they were all deposited at the same time — have been found on eight separate

paleocontinent A paleocontinent or palaeocontinent is a distinct area of continental crust that existed as a major landmass in the geological past. There have been many different landmasses throughout Earth's time. They range in sizes, some are just a collectio ...

s, in some cases occurring close to the

equator The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can also ...

(at a latitude of 10–30°). The 300 m-thick name-bearing section at Gaskiers (Newfoundland) is packed full of striated

dropstone Dropstones are isolated fragments of rock found within finer-grained water-deposited sedimentary rocks or pyroclastic beds. They range in size from small pebbles to boulders. The critical distinguishing feature is that there is evidence that the ...

s. Its values are very low (pushing ), consistent with a period of environmental abnormality. The bed lies just below some of the oldest fossils of the

Ediacaran biota The Ediacaran (; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were composed of enigmatic tubular and frond-shaped, mostly sess ...

, leading to early suggestions that the passing of the glaciation and the subsequent sharp rise in the ocean

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

levels may have paved the way for the evolution of these odd organisms. More accurate dating methods have shown that there is a 9 million year gap between the diamictites and the 570 Ma macrofossils. The Bou-Azzer glaciation, an Ediacaran glaciation known from evidence collected from the

West African Craton The West African Craton (WAC) is one of the five cratons of the Precambrian basement rock of Africa that make up the African Plate, the others being the Kalahari craton, Congo craton, Saharan Metacraton and Tanzania Craton.Jessell M.W., Liégeo ...

, 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.

References

Ediacaran geology Ice ages Glaciology {{glaciology-stub