Historical Geology: A Timeline of Earth’s Formation and Evolution Geology is the study of the Earth’s physical structure, history, and processes that have shaped the planet over millions of years. It helps us understand the world we live in and how it came to be. One branch of geology, known as Historical Geology, focuses on the Earth’s formation and evolution over its 4.5 billion-year history. In this article, we will delve deeper into what historical geology is, why it is important, and how it is studied.