Snowball Earth
Proper noun
Meaning
Snowball Earth
(geology) The planet Earth when its surface was almost completely frozen some time earlier than 650 million years ago, according to a hypothesis aiming to explain certain enigmatic features in the geological record, such as apparently glacial sedimentary deposits found at tropical paleolatitudes.
Examples
Gernon et al. demonstrated that the increase in alkalinity over the course of glaciation is sufficient to explain the thickness of cap carbonates formed in the aftermath of Snowball Earth events.
One of the most delved into is the Sturtian-Varangian glaciation, around 600 Ma, which may have brought glacial conditions all the way to the equator, resulting in a " Snowball Earth ".
Snowball Earth scenario Water flowing over iron-rich beds Until 1992, Kirschvink, Joseph (1992).
Some scenarios such as the Snowball Earth or research into the extinction events have raised the possibility that life on Earth is relatively fragile.
The same tillites also provide some support to the Precambrian Snowball Earth glaciation event hypothesis.
These glaciations are believed to have been so severe that there were ice sheets at the equator—a state known as the " Snowball Earth ".