Historical geology is the study of the Earth's history through its rock layers and fossils. It helps scientists understand how the planet has changed over millions of years, including the formation of continents, oceans, and various life forms. By examining sedimentary rocks and their structures, researchers can reconstruct past environments and events. This field also explores major geological events, such as plate tectonics, volcanic eruptions, and mass extinctions. By analyzing these occurrences, historical geologists can gain insights into the processes that shaped the Earth and how life has evolved in response to changing conditions over time.