Sturtian glaciation

Proterozoic snowball periods
−750 —
−725 —
−700 —
−675 —
−650 —
−625 —
−600 —
−575 —
−550 —
−525 —
Estimate of Proterozoic glacial periods.
Vertical axis: millions of years ago

The Sturtian glaciation, also known as the Sturt glaciation, was a worldwide glaciation during the Cryogenian Period when the Earth experienced repeated large-scale glaciations. The Sturtian glaciation is thought to have lasted from c. 717 Ma to c. 660 Ma, a time span of approximately 57 million years. It is hypothesised to have been a Snowball Earth event, or contrastingly multiple regional glaciations, and is the longest and most severe known glacial event preserved in the geologic record after the much earlier Huronian glaciation.