The brief ice age
340,000 years of ice — and immediately afterwards, animals
See it on the timeline →In depth
The Gaskiers glaciation in Newfoundland is dated unusually precisely using ash beds, to 579.63–579.88 million years. Unlike the Cryogenian snowballs it was brief and probably confined to higher latitudes. Its significance lies in the stratigraphy: the Avalon assemblage at Mistaken Point sits a few metres above the Gaskiers deposits. Whether the link is causal or coincidental is unresolved, but it is one of the sharpest temporal associations between a climate event and an evolutionary leap in the entire fossil record.
For children
A third ice age came, but this one was short and did not reach the tropics. It lasted only about 340,000 years. What matters is what happens immediately afterwards: in the rocks just above the glacial deposits we find the very first large, complex life forms.
Connects to
Part of Terra Saga — the story of Earth on a timeline. terrasaga.org