GENERAL GEOLOGY

Detailed explanation-1: -The Hadean, Archean, and Proterozoic eons together are called Precambrian time and make up almost 90 percent of Earth’s history.

Detailed explanation-2: -Precambrian (Informal-4.6 billion years ago to 541 million years ago) Precambrian is the informal name for the first 4 billion years, or 88 percent, of Earth’s history.

Detailed explanation-3: -The Precambrian encompasses nearly 90% of the history of the Earth and around a third of the history of the Universe. The Precambrian begins with the formation of the Solar System 4.57 billion years ago (bya) and extends to the beginning of the Cambrian 540 million years ago (Mya, or 0.54 bya).

Detailed explanation-4: -Precambrian time covers the vast bulk of the Earth’s history, starting with the planet’s creation about 4.5 billion years ago and ending with the emergence of complex, multicelled life-forms almost four billion years later.