Not that weâd expect less after the cliffhanger last season. If you havenât yet watched the September 23rd premiere of Chicago Fire, and somehow have managed not to find out who died, donât keep reading. If you have, please join me in my misery.
The Precambrian Super-Eon lasted from the formation of Earth 4,567 million years ago until the start of the Pharerozoic Eon 542 million years ago. It lasted 4.025 billion years. 90% of Earth's history.
The Precambrian is usually considered to have three eons: the Hadean, the Archean and the Proterozoic. Some scientists recognize a fourth eon, which they call the Chaotian, which predates the others and is the time of the first formation of our solar system. The Hadean Eon occurred 4.6 billion to 4 billion years ago.