Identifying Text Structure in History

In the book 'A Journey Through Time', the author describes various epochs in Earth's history, detailing events that shaped the planet. The book opens with a chapter about the formation of the Earth, discussing volcanic activity and the cooling of the planet.

Following this, the second chapter shifts to the emergence of life, highlighting the evolution of single-celled organisms. The third chapter focuses on the age of dinosaurs, describing their dominance and eventual extinction.

Which text structure is primarily employed in this book to organize the information?