GENERAL GEOLOGY

Detailed explanation-1: -Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago.

Detailed explanation-2: -During the Paleozoic Era, which lasted 289 million years, plants and reptiles began moving from the sea to the land. The era has been divided into six periods: Permian, Carboniferous, Devonian, Silurian, Ordovician, and Cambrian.

Detailed explanation-3: -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. It includes the Proterozoic and Archeon Eons.

Detailed explanation-4: -Eons are the largest intervals of geologic time and are hundreds of millions of years in duration. In the time scale above you can see the Phanerozoic Eon is the most recent eon and began more than 500 million years ago. Eons are divided into smaller time intervals known as eras.

Detailed explanation-5: -The period of Earth’s history that began 2.5 billion years ago and ended 542.0 million years ago is known as the Proterozoic, which is subdivided into three eras: the Paleoproterozoic (2.5 to 1.6 billion years ago), Mesoproterozoic (1.6 to 1 billion years ago), and Neoproterozoic (1 billion to 542.0 million years ago).