Interesting Article About the Great Unconformity

Mass glaciation?:

According to the team, at intervals within those billion or so years, up to a third of Earth’s crust was sawn off by Snowball Earth’s roaming glaciers and their erosive capabilities. The resulting sediment was dumped into the slush-covered oceans, where it was then sucked into the mantle by subducting tectonic plates.

...Effectively, in many locations, Earth buried the evidence of about a fifth of its geological history....