Historical geology

[3] 18th-century geologist James Hutton contributed to an early understanding of the Earth's history by proposing the theory of uniformitarianism, which is now a basic principle in all branches of geology.

Uniformitarianism describes an Earth formed by the same natural phenomena that are at work today, the product of slow and continuous geological changes.

[8] Modern geologists have generally acknowledged that Earth's geological history is a product of both sudden, cataclysmic events (such as meteorite impacts and volcanic eruptions) and gradual processes (such as weathering, erosion, and deposition).

Layers of rock, or strata, represent a geologic record of Earth's history.

Sedimentary rocks, including limestone, sandstone, and shale, serve as a record of Earth's history: they contain fossils and are transformed by geological processes, such as weathering, erosion, and deposition, through deep time.

[10] Absolute dating allows geologists to determine a more precise chronology of geological events, based on numerical ages or ranges.