Marinoan glaciation

geology

Also known as: Varanger-Marinoan glaciation

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June 30, 2026

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The Marinoan glaciation was a period of extreme global cooling that occurred approximately 650 to 635 million years ago, during the Cryogenian Period. This event is part of the broader "Snowball Earth" hypothesis, which suggests that Earth's surface was largely or entirely covered in ice.12

Evidence for this glaciation includes glacial deposits found near the Equator, indicating that ice sheets extended to low latitudes. The cause is thought to be linked to volcanic activity associated with the breakup of the supercontinent Rodinia, which released gases that increased weathering and removed carbon dioxide from the atmosphere, weakening the greenhouse effect.21

The thawing of this ice age is theorized to have been triggered by massive amounts of carbon dioxide released by volcanoes, which enhanced the greenhouse effect and warmed the planet. Life may have survived in areas like hydrothermal vents or meltwater ponds.21

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Ediacaran Period
The Ediacaran environment
…and glaciers associated with the Marinoan (or Varanger-Marinoan) glaciation—which began near the end of the Cryogenian Period and ended approximately 635 million years ago—and declines in the carbon isotope composition of marine rocks. Oxygen levels rose in the atmosphere and in the oceans, and many scholars suggest that the change…
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…and glaciers associated with the Marinoan (or Varanger-Marinoan) glaciation—which began near the end of the Cryogenian Period and ended approximately 635 million years ago—and declines in the carbon isotope composition of marine rocks. Oxygen levels rose in the atmosphere and in the oceans, and many scholars suggest that the change…
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Australia
The Precambrian
…newly rifted troughs; the younger Marinoan glaciation is represented by diamictites deposited on the basin floor and sandstone on the shelf. The Wilpena group comprises extensive sheets of interbedded sandstone, siltstone, and shale deposited during two marine transgressions, during the second of which deep canyons were cut and filled. The…
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…newly rifted troughs; the younger Marinoan glaciation is represented by diamictites deposited on the basin floor and sandstone on the shelf. The Wilpena group comprises extensive sheets of interbedded sandstone, siltstone, and shale deposited during two marine transgressions, during the second of which deep canyons were cut and filled. The…
Read More