411 REFERENCE · Wiktionary
Snowball Earth
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Proper noun
Snowball Earth
en 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.
Coordinate terms
en banded ironstone formation banded iron formation BIF