Before revision: Huronian Glaciation – an icehouse period that ran from 2.4 billion to 2.1 billion years ago A greenhouse period ran from 2.1 billion to 720 million years ago.
After revision: Huronian glaciation – an icehouse period that ran from 2.4 billion to 2.1 billion years ago A greenhouse period ran from 2.1 billion to 720 million years ago.